Preconditions.java
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.base;
import static com.google.common.base.Strings.lenientFormat;
import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* Static convenience methods that help a method or constructor check whether it was invoked
* correctly (that is, whether its <i>preconditions</i> were met).
*
* <p>If the precondition is not met, the {@code Preconditions} method throws an unchecked exception
* of a specified type, which helps the method in which the exception was thrown communicate that
* its caller has made a mistake. This allows constructs such as
*
* <pre>{@code
* public static double sqrt(double value) {
* if (value < 0) {
* throw new IllegalArgumentException("input is negative: " + value);
* }
* // calculate square root
* }
* }</pre>
*
* <p>to be replaced with the more compact
*
* <pre>{@code
* public static double sqrt(double value) {
* checkArgument(value >= 0, "input is negative: %s", value);
* // calculate square root
* }
* }</pre>
*
* <p>so that a hypothetical bad caller of this method, such as:
*
* <pre>{@code
* void exampleBadCaller() {
* double d = sqrt(-1.0);
* }
* }</pre>
*
* <p>would be flagged as having called {@code sqrt()} with an illegal argument.
*
* <h3>Performance</h3>
*
* <p>Avoid passing message arguments that are expensive to compute; your code will always compute
* them, even though they usually won't be needed. If you have such arguments, use the conventional
* if/throw idiom instead.
*
* <p>Depending on your message arguments, memory may be allocated for boxing and varargs array
* creation. However, the methods of this class have a large number of overloads that prevent such
* allocations in many common cases.
*
* <p>The message string is not formatted unless the exception will be thrown, so the cost of the
* string formatting itself should not be a concern.
*
* <p>As with any performance concerns, you should consider profiling your code (in a production
* environment if possible) before spending a lot of effort on tweaking a particular element.
*
* <h3>Other types of preconditions</h3>
*
* <p>Not every type of precondition failure is supported by these methods. Continue to throw
* standard JDK exceptions such as {@link java.util.NoSuchElementException} or {@link
* UnsupportedOperationException} in the situations they are intended for.
*
* <h3>Non-preconditions</h3>
*
* <p>It is of course possible to use the methods of this class to check for invalid conditions
* which are <i>not the caller's fault</i>. Doing so is <b>not recommended</b> because it is
* misleading to future readers of the code and of stack traces. See <a
* href="https://github.com/google/guava/wiki/ConditionalFailuresExplained">Conditional failures
* explained</a> in the Guava User Guide for more advice. Notably, {@link Verify} offers assertions
* similar to those in this class for non-precondition checks.
*
* <h3>{@code java.util.Objects.requireNonNull()}</h3>
*
* <p>Projects which use {@code com.google.common} should generally avoid the use of {@link
* java.util.Objects#requireNonNull(Object)}. Instead, use whichever of {@link
* #checkNotNull(Object)} or {@link Verify#verifyNotNull(Object)} is appropriate to the situation.
* (The same goes for the message-accepting overloads.)
*
* <h3>Only {@code %s} is supported</h3>
*
* <p>{@code Preconditions} uses {@link Strings#lenientFormat} to format error message template
* strings. This only supports the {@code "%s"} specifier, not the full range of {@link
* java.util.Formatter} specifiers. However, note that if the number of arguments does not match the
* number of occurrences of {@code "%s"} in the format string, {@code Preconditions} will still
* behave as expected, and will still include all argument values in the error message; the message
* will simply not be formatted exactly as intended.
*
* <h3>More information</h3>
*
* <p>See the Guava User Guide on <a
* href="https://github.com/google/guava/wiki/PreconditionsExplained">using {@code
* Preconditions}</a>.
*
* @author Kevin Bourrillion
* @since 2.0
*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Preconditions {
private Preconditions() {}
// TODO(cpovirk): Standardize parameter names (expression vs. b, reference vs. obj).
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* @param expression a boolean expression
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(boolean expression) {
if (!expression) {
throw new IllegalArgumentException();
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessage the exception message to use if the check fails; will be converted to a
* string using {@link String#valueOf(Object)}
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(boolean expression, @CheckForNull Object errorMessage) {
if (!expression) {
throw new IllegalArgumentException(String.valueOf(errorMessage));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessageTemplate a template for the exception message should the check fail. The
* message is formed by replacing each {@code %s} placeholder in the template with an
* argument. These are matched by position - the first {@code %s} gets {@code
* errorMessageArgs[0]}, etc. Unmatched arguments will be appended to the formatted message in
* square braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message template. Arguments
* are converted to strings using {@link String#valueOf(Object)}.
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(
boolean expression,
String errorMessageTemplate,
@CheckForNull @Nullable Object... errorMessageArgs) {
if (!expression) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, errorMessageArgs));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, char p1) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, int p1) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, long p1) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, @CheckForNull Object p1) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, char p1, char p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, char p1, int p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, char p1, long p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, char p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, int p1, char p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, int p1, int p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, int p1, long p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, int p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, long p1, char p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, long p1, int p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(boolean b, String errorMessageTemplate, long p1, long p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, long p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, char p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, int p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, long p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b,
String errorMessageTemplate,
@CheckForNull Object p1,
@CheckForNull Object p2,
@CheckForNull Object p3) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2, p3));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* <p>See {@link #checkArgument(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkArgument(
boolean b,
String errorMessageTemplate,
@CheckForNull Object p1,
@CheckForNull Object p2,
@CheckForNull Object p3,
@CheckForNull Object p4) {
if (!b) {
throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2, p3, p4));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* @param expression a boolean expression
* @throws IllegalStateException if {@code expression} is false
* @see Verify#verify Verify.verify()
*/
public static void checkState(boolean expression) {
if (!expression) {
throw new IllegalStateException();
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessage the exception message to use if the check fails; will be converted to a
* string using {@link String#valueOf(Object)}
* @throws IllegalStateException if {@code expression} is false
* @see Verify#verify Verify.verify()
*/
public static void checkState(boolean expression, @CheckForNull Object errorMessage) {
if (!expression) {
throw new IllegalStateException(String.valueOf(errorMessage));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessageTemplate a template for the exception message should the check fail. The
* message is formed by replacing each {@code %s} placeholder in the template with an
* argument. These are matched by position - the first {@code %s} gets {@code
* errorMessageArgs[0]}, etc. Unmatched arguments will be appended to the formatted message in
* square braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message template. Arguments
* are converted to strings using {@link String#valueOf(Object)}.
* @throws IllegalStateException if {@code expression} is false
* @see Verify#verify Verify.verify()
*/
public static void checkState(
boolean expression,
/*
* TODO(cpovirk): Consider removing @CheckForNull here, as we've done with the other methods'
* errorMessageTemplate parameters: It it unlikely that callers intend for their string
* template to be null (though we do handle that case gracefully at runtime). I've left this
* one as it is because one of our users has defined a wrapper API around Preconditions,
* declaring a checkState method that accepts a possibly null template. So we'd need to update
* that user first.
*/
@CheckForNull String errorMessageTemplate,
@CheckForNull @Nullable Object... errorMessageArgs) {
if (!expression) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, errorMessageArgs));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, char p1) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, int p1) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, long p1) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, @CheckForNull Object p1) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, char p1, char p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, char p1, int p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, char p1, long p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b, String errorMessageTemplate, char p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, int p1, char p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, int p1, int p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, int p1, long p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b, String errorMessageTemplate, int p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, long p1, char p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, long p1, int p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(boolean b, String errorMessageTemplate, long p1, long p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b, String errorMessageTemplate, long p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, char p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, int p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, long p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b, String errorMessageTemplate, @CheckForNull Object p1, @CheckForNull Object p2) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b,
String errorMessageTemplate,
@CheckForNull Object p1,
@CheckForNull Object p2,
@CheckForNull Object p3) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2, p3));
}
}
/**
* Ensures the truth of an expression involving the state of the calling instance, but not
* involving any parameters to the calling method.
*
* <p>See {@link #checkState(boolean, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
public static void checkState(
boolean b,
String errorMessageTemplate,
@CheckForNull Object p1,
@CheckForNull Object p2,
@CheckForNull Object p3,
@CheckForNull Object p4) {
if (!b) {
throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2, p3, p4));
}
}
/*
* Preconditions.checkNotNull is *intended* for performing eager null checks on parameters that a
* nullness checker can already "prove" are non-null. That means that the first parameter to
* checkNotNull *should* be annotated to require it to be non-null.
*
* However, for a variety of reasons, Google developers have written a ton of code over the past
* decade that assumes that they can use checkNotNull for non-precondition checks. I had hoped to
* take a principled stand on this, but the amount of such code is simply overwhelming. To avoid
* creating a lot of compile errors that users would not find to be informative, we're giving in
* and allowing callers to pass arguments that a nullness checker believes could be null.
*
* We still encourage people to use requireNonNull over checkNotNull for non-precondition checks.
*/
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* @param reference an object reference
* @return the non-null reference that was validated
* @throws NullPointerException if {@code reference} is null
* @see Verify#verifyNotNull Verify.verifyNotNull()
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(@CheckForNull T reference) {
if (reference == null) {
throw new NullPointerException();
}
return reference;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* @param reference an object reference
* @param errorMessage the exception message to use if the check fails; will be converted to a
* string using {@link String#valueOf(Object)}
* @return the non-null reference that was validated
* @throws NullPointerException if {@code reference} is null
* @see Verify#verifyNotNull Verify.verifyNotNull()
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(@CheckForNull T reference, @CheckForNull Object errorMessage) {
if (reference == null) {
throw new NullPointerException(String.valueOf(errorMessage));
}
return reference;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* @param reference an object reference
* @param errorMessageTemplate a template for the exception message should the check fail. The
* message is formed by replacing each {@code %s} placeholder in the template with an
* argument. These are matched by position - the first {@code %s} gets {@code
* errorMessageArgs[0]}, etc. Unmatched arguments will be appended to the formatted message in
* square braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message template. Arguments
* are converted to strings using {@link String#valueOf(Object)}.
* @return the non-null reference that was validated
* @throws NullPointerException if {@code reference} is null
* @see Verify#verifyNotNull Verify.verifyNotNull()
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T reference,
String errorMessageTemplate,
@CheckForNull @Nullable Object... errorMessageArgs) {
if (reference == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, errorMessageArgs));
}
return reference;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(@CheckForNull T obj, String errorMessageTemplate, char p1) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(@CheckForNull T obj, String errorMessageTemplate, int p1) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(@CheckForNull T obj, String errorMessageTemplate, long p1) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, @CheckForNull Object p1) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, char p1, char p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, char p1, int p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, char p1, long p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, char p1, @CheckForNull Object p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, int p1, char p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, int p1, int p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, int p1, long p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, int p1, @CheckForNull Object p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, long p1, char p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, long p1, int p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, long p1, long p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, long p1, @CheckForNull Object p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, @CheckForNull Object p1, char p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, @CheckForNull Object p1, int p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj, String errorMessageTemplate, @CheckForNull Object p1, long p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj,
String errorMessageTemplate,
@CheckForNull Object p1,
@CheckForNull Object p2) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj,
String errorMessageTemplate,
@CheckForNull Object p1,
@CheckForNull Object p2,
@CheckForNull Object p3) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2, p3));
}
return obj;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* <p>See {@link #checkNotNull(Object, String, Object...)} for details.
*
* @since 20.0 (varargs overload since 2.0)
*/
@CanIgnoreReturnValue
public static <T> T checkNotNull(
@CheckForNull T obj,
String errorMessageTemplate,
@CheckForNull Object p1,
@CheckForNull Object p2,
@CheckForNull Object p3,
@CheckForNull Object p4) {
if (obj == null) {
throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2, p3, p4));
}
return obj;
}
/*
* All recent hotspots (as of 2009) *really* like to have the natural code
*
* if (guardExpression) {
* throw new BadException(messageExpression);
* }
*
* refactored so that messageExpression is moved to a separate String-returning method.
*
* if (guardExpression) {
* throw new BadException(badMsg(...));
* }
*
* The alternative natural refactorings into void or Exception-returning methods are much slower.
* This is a big deal - we're talking factors of 2-8 in microbenchmarks, not just 10-20%. (This is
* a hotspot optimizer bug, which should be fixed, but that's a separate, big project).
*
* The coding pattern above is heavily used in java.util, e.g. in ArrayList. There is a
* RangeCheckMicroBenchmark in the JDK that was used to test this.
*
* But the methods in this class want to throw different exceptions, depending on the args, so it
* appears that this pattern is not directly applicable. But we can use the ridiculous, devious
* trick of throwing an exception in the middle of the construction of another exception. Hotspot
* is fine with that.
*/
/**
* Ensures that {@code index} specifies a valid <i>element</i> in an array, list or string of size
* {@code size}. An element index may range from zero, inclusive, to {@code size}, exclusive.
*
* @param index a user-supplied index identifying an element of an array, list or string
* @param size the size of that array, list or string
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is not less than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
@CanIgnoreReturnValue
public static int checkElementIndex(int index, int size) {
return checkElementIndex(index, size, "index");
}
/**
* Ensures that {@code index} specifies a valid <i>element</i> in an array, list or string of size
* {@code size}. An element index may range from zero, inclusive, to {@code size}, exclusive.
*
* @param index a user-supplied index identifying an element of an array, list or string
* @param size the size of that array, list or string
* @param desc the text to use to describe this index in an error message
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is not less than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
@CanIgnoreReturnValue
public static int checkElementIndex(int index, int size, String desc) {
// Carefully optimized for execution by hotspot (explanatory comment above)
if (index < 0 || index >= size) {
throw new IndexOutOfBoundsException(badElementIndex(index, size, desc));
}
return index;
}
private static String badElementIndex(int index, int size, String desc) {
if (index < 0) {
return lenientFormat("%s (%s) must not be negative", desc, index);
} else if (size < 0) {
throw new IllegalArgumentException("negative size: " + size);
} else { // index >= size
return lenientFormat("%s (%s) must be less than size (%s)", desc, index, size);
}
}
/**
* Ensures that {@code index} specifies a valid <i>position</i> in an array, list or string of
* size {@code size}. A position index may range from zero to {@code size}, inclusive.
*
* @param index a user-supplied index identifying a position in an array, list or string
* @param size the size of that array, list or string
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is greater than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
@CanIgnoreReturnValue
public static int checkPositionIndex(int index, int size) {
return checkPositionIndex(index, size, "index");
}
/**
* Ensures that {@code index} specifies a valid <i>position</i> in an array, list or string of
* size {@code size}. A position index may range from zero to {@code size}, inclusive.
*
* @param index a user-supplied index identifying a position in an array, list or string
* @param size the size of that array, list or string
* @param desc the text to use to describe this index in an error message
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is greater than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
@CanIgnoreReturnValue
public static int checkPositionIndex(int index, int size, String desc) {
// Carefully optimized for execution by hotspot (explanatory comment above)
if (index < 0 || index > size) {
throw new IndexOutOfBoundsException(badPositionIndex(index, size, desc));
}
return index;
}
private static String badPositionIndex(int index, int size, String desc) {
if (index < 0) {
return lenientFormat("%s (%s) must not be negative", desc, index);
} else if (size < 0) {
throw new IllegalArgumentException("negative size: " + size);
} else { // index > size
return lenientFormat("%s (%s) must not be greater than size (%s)", desc, index, size);
}
}
/**
* Ensures that {@code start} and {@code end} specify valid <i>positions</i> in an array, list or
* string of size {@code size}, and are in order. A position index may range from zero to {@code
* size}, inclusive.
*
* @param start a user-supplied index identifying a starting position in an array, list or string
* @param end a user-supplied index identifying an ending position in an array, list or string
* @param size the size of that array, list or string
* @throws IndexOutOfBoundsException if either index is negative or is greater than {@code size},
* or if {@code end} is less than {@code start}
* @throws IllegalArgumentException if {@code size} is negative
*/
public static void checkPositionIndexes(int start, int end, int size) {
// Carefully optimized for execution by hotspot (explanatory comment above)
if (start < 0 || end < start || end > size) {
throw new IndexOutOfBoundsException(badPositionIndexes(start, end, size));
}
}
private static String badPositionIndexes(int start, int end, int size) {
if (start < 0 || start > size) {
return badPositionIndex(start, size, "start index");
}
if (end < 0 || end > size) {
return badPositionIndex(end, size, "end index");
}
// end < start
return lenientFormat("end index (%s) must not be less than start index (%s)", end, start);
}
}