org.springframework.util.function.ThrowingBiFunction Maven / Gradle / Ivy
/*
* Copyright 2002-2022 the original author or 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
*
* https://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 org.springframework.util.function;
import java.util.function.BiFunction;
/**
* A {@link BiFunction} that allows invocation of code that throws a checked
* exception.
*
* @author Stephane Nicoll
* @author Phillip Webb
* @since 6.0
* @param the type of the first argument to the function
* @param the type of the second argument to the function
* @param the type of the result of the function
*/
public interface ThrowingBiFunction extends BiFunction {
/**
* Applies this function to the given argument, possibly throwing a checked
* exception.
* @param t the first function argument
* @param u the second function argument
* @return the function result
* @throws Exception on error
*/
R applyWithException(T t, U u) throws Exception;
/**
* Default {@link BiFunction#apply(Object, Object)} that wraps any thrown
* checked exceptions (by default in a {@link RuntimeException}).
* @param t the first function argument
* @param u the second function argument
* @return the function result
* @see java.util.function.BiFunction#apply(Object, Object)
*/
@Override
default R apply(T t, U u) {
return apply(t, u, RuntimeException::new);
}
/**
* Applies this function to the given argument, wrapping any thrown checked
* exceptions using the given {@code exceptionWrapper}.
* @param t the first function argument
* @param u the second function argument
* @param exceptionWrapper {@link BiFunction} that wraps the given message
* and checked exception into a runtime exception
* @return a result
*/
default R apply(T t, U u, BiFunction exceptionWrapper) {
try {
return applyWithException(t, u);
}
catch (RuntimeException ex) {
throw ex;
}
catch (Exception ex) {
throw exceptionWrapper.apply(ex.getMessage(), ex);
}
}
/**
* Return a new {@link ThrowingBiFunction} where the
* {@link #apply(Object, Object)} method wraps any thrown checked exceptions
* using the given {@code exceptionWrapper}.
* @param exceptionWrapper {@link BiFunction} that wraps the given message
* and checked exception into a runtime exception
* @return the replacement {@link ThrowingBiFunction} instance
*/
default ThrowingBiFunction throwing(BiFunction exceptionWrapper) {
return new ThrowingBiFunction<>() {
@Override
public R applyWithException(T t, U u) throws Exception {
return ThrowingBiFunction.this.applyWithException(t, u);
}
@Override
public R apply(T t, U u) {
return apply(t, u, exceptionWrapper);
}
};
}
/**
* Lambda friendly convenience method that can be used to create a
* {@link ThrowingBiFunction} where the {@link #apply(Object, Object)}
* method wraps any checked exception thrown by the supplied lambda expression
* or method reference.
* This method can be especially useful when working with method references.
* It allows you to easily convert a method that throws a checked exception
* into an instance compatible with a regular {@link BiFunction}.
*
For example:
*
* map.replaceAll(ThrowingBiFunction.of(Example::methodThatCanThrowCheckedException));
*
* @param the type of the first argument to the function
* @param the type of the second argument to the function
* @param the type of the result of the function
* @param function the source function
* @return a new {@link ThrowingFunction} instance
*/
static ThrowingBiFunction of(ThrowingBiFunction function) {
return function;
}
/**
* Lambda friendly convenience method that can be used to create a
* {@link ThrowingBiFunction} where the {@link #apply(Object, Object)}
* method wraps any thrown checked exceptions using the given
* {@code exceptionWrapper}.
* This method can be especially useful when working with method references.
* It allows you to easily convert a method that throws a checked exception
* into an instance compatible with a regular {@link BiFunction}.
*
For example:
*
* map.replaceAll(ThrowingBiFunction.of(Example::methodThatCanThrowCheckedException, IllegalStateException::new));
*
* @param the type of the first argument to the function
* @param the type of the second argument to the function
* @param the type of the result of the function
* @param function the source function
* @param exceptionWrapper the exception wrapper to use
* @return a new {@link ThrowingFunction} instance
*/
static ThrowingBiFunction of(ThrowingBiFunction function,
BiFunction exceptionWrapper) {
return function.throwing(exceptionWrapper);
}
}