Add Throwable functional interfaces

Add 'Throwable' variants of the `Consumer`, `Function`, `BiFunction` and
`Supplier` interfaces that wrap checked exceptions or allow calls to be
made that throw them.

Closes gh-28417

spring-core/src/main/java/org/springframework/util/function/ThrowingBiFunction.java

@@ -0,0 +1,135 @@
+/*
+ * 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 <T> the type of the first argument to the function
+ * @param <U> the type of the second argument to the function
+ * @param <R> the type of the result of the function
+ */
+public interface ThrowingBiFunction<T, U, R> extends BiFunction<T, U, R> {
+
+	/**
+	 * 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<String, Exception, RuntimeException> 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<T, U, R> throwing(BiFunction<String, Exception, RuntimeException> 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
+	 * {@link ThrowingBiFunction} where the {@link #apply(Object, Object)}
+	 * method wraps any thrown checked exceptions using the given
+	 * {@code exceptionWrapper}.
+	 * @param <T> the type of the first argument to the function
+	 * @param <U> the type of the second argument to the function
+	 * @param <R> the type of the result of the function
+	 * @param function the source function
+	 * @return a new {@link ThrowingFunction} instance
+	 */
+	static <T, U, R> ThrowingBiFunction<T, U, R> of(ThrowingBiFunction<T, U, R> function) {
+		return function;
+	}
+
+	/**
+	 * Lambda friendly convenience method that can be used to create
+	 * {@link ThrowingBiFunction} where the {@link #apply(Object, Object)}
+	 * method wraps any thrown checked exceptions using the given
+	 * {@code exceptionWrapper}.
+	 * @param <T> the type of the first argument to the function
+	 * @param <U> the type of the second argument to the function
+	 * @param <R> 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 <T, U, R> ThrowingBiFunction<T, U, R> of(ThrowingBiFunction<T, U, R> function,
+			BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+
+		return function.throwing(exceptionWrapper);
+	}
+
+}

spring-core/src/main/java/org/springframework/util/function/ThrowingConsumer.java

@@ -0,0 +1,121 @@
+/*
+ * 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;
+import java.util.function.Consumer;
+
+/**
+ * A {@link Consumer} that allows invocation of code that throws a checked
+ * exception.
+ *
+ * @author Stephane Nicoll
+ * @author Phillip Webb
+ * @since 6.0
+ * @param <T> the type of the input to the operation
+ */
+@FunctionalInterface
+public interface ThrowingConsumer<T> extends Consumer<T> {
+
+	/**
+	 * Performs this operation on the given argument, possibly throwing a
+	 * checked exception.
+	 * @param t the input argument
+	 * @throws Exception on error
+	 */
+	void acceptWithException(T t) throws Exception;
+
+	/**
+	 * Default {@link Consumer#accept(Object)} that wraps any thrown checked
+	 * exceptions (by default in a {@link RuntimeException}).
+	 * @see java.util.function.Consumer#accept(Object)
+	 */
+	@Override
+	default void accept(T t) {
+		accept(t, RuntimeException::new);
+	}
+
+	/**
+	 * Performs this operation on the given argument, wrapping 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
+	 */
+	default void accept(T t,BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+		try {
+			acceptWithException(t);
+		}
+		catch (RuntimeException ex) {
+			throw ex;
+		}
+		catch (Exception ex) {
+			throw exceptionWrapper.apply(ex.getMessage(), ex);
+		}
+	}
+
+	/**
+	 * Return a new {@link ThrowingConsumer} where the {@link #accept(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 ThrowingConsumer} instance
+	 */
+	default ThrowingConsumer<T> throwing(BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+		return new ThrowingConsumer<>() {
+
+			@Override
+			public void acceptWithException(T t) throws Exception {
+				ThrowingConsumer.this.acceptWithException(t);
+			}
+
+			@Override
+			public void accept(T t) {
+				accept(t, exceptionWrapper);
+			}
+
+		};
+	}
+
+	/**
+	 * Lambda friendly convenience method that can be used to create
+	 * {@link ThrowingConsumer} where the {@link #accept(Object)} method wraps
+	 * any thrown checked exceptions using the given {@code exceptionWrapper}.
+	 * @param <T> the type of the input to the operation
+	 * @param consumer the source consumer
+	 * @return a new {@link ThrowingConsumer} instance
+	 */
+	static <T> ThrowingConsumer<T> of(ThrowingConsumer<T> consumer) {
+		return consumer;
+	}
+
+	/**
+	 * Lambda friendly convenience method that can be used to create
+	 * {@link ThrowingConsumer} where the {@link #accept(Object)} method wraps
+	 * any thrown checked exceptions using the given {@code exceptionWrapper}.
+	 * @param <T> the type of the input to the operation
+	 * @param consumer the source consumer
+	 * @param exceptionWrapper the exception wrapper to use
+	 * @return a new {@link ThrowingConsumer} instance
+	 */
+	static <T> ThrowingConsumer<T> of(ThrowingConsumer<T> consumer,
+			BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+
+		return consumer.throwing(exceptionWrapper);
+	}
+
+}

spring-core/src/main/java/org/springframework/util/function/ThrowingFunction.java

@@ -0,0 +1,126 @@
+/*
+ * 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;
+import java.util.function.Function;
+
+/**
+ * A {@link Function} that allows invocation of code that throws a checked
+ * exception.
+ *
+ * @author Stephane Nicoll
+ * @author Phillip Webb
+ * @since 6.0
+ * @param <T> the type of the input to the function
+ * @param <R> the type of the result of the function
+ */
+@FunctionalInterface
+public interface ThrowingFunction<T, R> extends Function<T, R> {
+
+	/**
+	 * Applies this function to the given argument, possibly throwing a checked
+	 * exception.
+	 * @param t the function argument
+	 * @return the function result
+	 * @throws Exception on error
+	 */
+	R applyWithException(T t) throws Exception;
+
+	/**
+	 * Default {@link Function#apply(Object)} that wraps any thrown checked
+	 * exceptions (by default in a {@link RuntimeException}).
+	 * @see java.util.function.Function#apply(java.lang.Object)
+	 */
+	@Override
+	default R apply(T t) {
+		return apply(t, RuntimeException::new);
+	}
+
+	/**
+	 * Applies this function to the given argument, wrapping 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 a result
+	 */
+	default R apply(T t, BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+		try {
+			return applyWithException(t);
+		}
+		catch (RuntimeException ex) {
+			throw ex;
+		}
+		catch (Exception ex) {
+			throw exceptionWrapper.apply(ex.getMessage(), ex);
+		}
+	}
+
+	/**
+	 * Return a new {@link ThrowingFunction} where the {@link #apply(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 ThrowingFunction} instance
+	 */
+	default ThrowingFunction<T, R> throwing(BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+		return new ThrowingFunction<>() {
+
+			@Override
+			public R applyWithException(T t) throws Exception {
+				return ThrowingFunction.this.applyWithException(t);
+			}
+
+			@Override
+			public R apply(T t) {
+				return apply(t, exceptionWrapper);
+			}
+
+		};
+	}
+
+	/**
+	 * Lambda friendly convenience method that can be used to create
+	 * {@link ThrowingFunction} where the {@link #apply(Object)} method wraps
+	 * any thrown checked exceptions using the given {@code exceptionWrapper}.
+	 * @param <T> the type of the input to the function
+	 * @param <R> the type of the result of the function
+	 * @param function the source function
+	 * @return a new {@link ThrowingFunction} instance
+	 */
+	static <T, R> ThrowingFunction<T, R> of(ThrowingFunction<T, R> function) {
+		return function;
+	}
+
+	/**
+	 * Lambda friendly convenience method that can be used to create
+	 * {@link ThrowingFunction} where the {@link #apply(Object)} method wraps
+	 * any thrown checked exceptions using the given {@code exceptionWrapper}.
+	 * @param <T> the type of the input to the function
+	 * @param <R> 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 <T, R> ThrowingFunction<T, R> of(ThrowingFunction<T, R> function,
+			BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+
+		return function.throwing(exceptionWrapper);
+	}
+
+}

spring-core/src/main/java/org/springframework/util/function/ThrowingSupplier.java

@@ -0,0 +1,120 @@
+/*
+ * 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;
+import java.util.function.Supplier;
+
+/**
+ * A {@link Supplier} that allows invocation of code that throws a checked
+ * exception.
+ *
+ * @author Stephane Nicoll
+ * @author Phillip Webb
+ * @since 6.0
+ * @param <T> the type of results supplied by this supplier
+ */
+public interface ThrowingSupplier<T> extends Supplier<T> {
+
+	/**
+	 * Gets a result, possibly throwing a checked exception.
+	 * @return a result
+	 * @throws Exception on error
+	 */
+	T getWithException() throws Exception;
+
+	/**
+	 * Default {@link Supplier#get()} that wraps any thrown checked exceptions
+	 * (by default in a {@link RuntimeException}).
+	 * @see java.util.function.Supplier#get()
+	 */
+	@Override
+	default T get() {
+		return get(RuntimeException::new);
+	}
+
+	/**
+	 * Gets a result, wrapping 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 a result
+	 */
+	default T get(BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+		try {
+			return getWithException();
+		}
+		catch (RuntimeException ex) {
+			throw ex;
+		}
+		catch (Exception ex) {
+			throw exceptionWrapper.apply(ex.getMessage(), ex);
+		}
+	}
+
+	/**
+	 * Return a new {@link ThrowingSupplier} where the {@link #get()} 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 ThrowingSupplier} instance
+	 */
+	default ThrowingSupplier<T> throwing(BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+		return new ThrowingSupplier<>() {
+
+			@Override
+			public T getWithException() throws Exception {
+				return ThrowingSupplier.this.getWithException();
+			}
+
+			@Override
+			public T get() {
+				return get(exceptionWrapper);
+			}
+
+		};
+	}
+
+	/**
+	 * Lambda friendly convenience method that can be used to create
+	 * {@link ThrowingSupplier} where the {@link #get()} method wraps any
+	 * thrown checked exceptions.
+	 * @param <T> the type of results supplied by this supplier
+	 * @param supplier the source supplier
+	 * @return a new {@link ThrowingSupplier} instance
+	 */
+	static <T> ThrowingSupplier<T> of(ThrowingSupplier<T> supplier) {
+		return supplier;
+	}
+
+	/**
+	 * Lambda friendly convenience method that can be used to create
+	 * {@link ThrowingSupplier} where the {@link #get()} method wraps any
+	 * thrown checked exceptions using the given {@code exceptionWrapper}.
+	 * @param <T> the type of results supplied by this supplier
+	 * @param supplier the source supplier
+	 * @param exceptionWrapper the exception wrapper to use
+	 * @return a new {@link ThrowingSupplier} instance
+	 */
+	static <T> ThrowingSupplier<T> of(ThrowingSupplier<T> supplier,
+			BiFunction<String, Exception, RuntimeException> exceptionWrapper) {
+
+		return supplier.throwing(exceptionWrapper);
+	}
+
+}

spring-core/src/test/java/org/springframework/util/function/ThrowingBiFunctionTests.java

@@ -0,0 +1,87 @@
+/*
+ * 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.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+
+/**
+ * Tests for {@link ThrowingBiFunction}.
+ *
+ * @author Phillip Webb
+ * @since 6.0
+ */
+class ThrowingBiFunctionTests {
+
+	@Test
+	void applyWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingBiFunction<Object, Object, Object> function = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(() -> function.apply(this, this));
+	}
+
+	@Test
+	void applyWhenThrowingCheckedExceptionThrowsWrapperRuntimeException() {
+		ThrowingBiFunction<Object, Object, Object> function = this::throwIOException;
+		assertThatExceptionOfType(RuntimeException.class).isThrownBy(
+				() -> function.apply(this, this)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void applyWithExceptionWrapperWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingBiFunction<Object, Object, Object> function = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(
+				() -> function.apply(this, this, IllegalStateException::new));
+	}
+
+	@Test
+	void applyWithExceptionWrapperWhenThrowingCheckedExceptionThrowsWrapper() {
+		ThrowingBiFunction<Object, Object, Object> function = this::throwIOException;
+		assertThatIllegalStateException().isThrownBy(() -> function.apply(this, this,
+				IllegalStateException::new)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void throwingModifiesThrownException() {
+		ThrowingBiFunction<Object, Object, Object> function = this::throwIOException;
+		ThrowingBiFunction<Object, Object, Object> modified = function.throwing(
+				IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> modified.apply(this, this)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void ofModifiesThrowException() {
+		ThrowingBiFunction<Object, Object, Object> function = ThrowingBiFunction.of(
+				this::throwIOException, IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> function.apply(this, this)).withCauseInstanceOf(IOException.class);
+	}
+
+	private Object throwIOException(Object o, Object u) throws IOException {
+		throw new IOException();
+	}
+
+	private Object throwIllegalArgumentException(Object o, Object u) throws IOException {
+		throw new IllegalArgumentException();
+	}
+
+}

spring-core/src/test/java/org/springframework/util/function/ThrowingConsumerTests.java

@@ -0,0 +1,87 @@
+/*
+ * 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.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+
+/**
+ * Tests for {@link ThrowingConsumer}.
+ *
+ * @author Phillip Webb
+ * @since 6.0
+ */
+class ThrowingConsumerTests {
+
+	@Test
+	void applyWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingConsumer<Object> consumer = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(() -> consumer.accept(this));
+	}
+
+	@Test
+	void applyWhenThrowingCheckedExceptionThrowsWrapperRuntimeException() {
+		ThrowingConsumer<Object> consumer = this::throwIOException;
+		assertThatExceptionOfType(RuntimeException.class).isThrownBy(
+				() -> consumer.accept(this)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void applyWithExceptionWrapperWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingConsumer<Object> consumer = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(
+				() -> consumer.accept(this, IllegalStateException::new));
+	}
+
+	@Test
+	void applyWithExceptionWrapperWhenThrowingCheckedExceptionThrowsWrapper() {
+		ThrowingConsumer<Object> consumer = this::throwIOException;
+		assertThatIllegalStateException().isThrownBy(() -> consumer.accept(this,
+				IllegalStateException::new)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void throwingModifiesThrownException() {
+		ThrowingConsumer<Object> consumer = this::throwIOException;
+		ThrowingConsumer<Object> modified = consumer.throwing(
+				IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> modified.accept(this)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void ofModifiesThrowException() {
+		ThrowingConsumer<Object> consumer = ThrowingConsumer.of(this::throwIOException,
+				IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> consumer.accept(this)).withCauseInstanceOf(IOException.class);
+	}
+
+	private void throwIOException(Object o) throws IOException {
+		throw new IOException();
+	}
+
+	private void throwIllegalArgumentException(Object o) throws IOException {
+		throw new IllegalArgumentException();
+	}
+
+}

spring-core/src/test/java/org/springframework/util/function/ThrowingFunctionTests.java

@@ -0,0 +1,87 @@
+/*
+ * 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.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+
+/**
+ * Tests for {@link ThrowingFunction}.
+ *
+ * @author Phillip Webb
+ * @since 6.0
+ */
+class ThrowingFunctionTests {
+
+	@Test
+	void applyWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingFunction<Object, Object> function = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(() -> function.apply(this));
+	}
+
+	@Test
+	void applyWhenThrowingCheckedExceptionThrowsWrapperRuntimeException() {
+		ThrowingFunction<Object, Object> function = this::throwIOException;
+		assertThatExceptionOfType(RuntimeException.class).isThrownBy(
+				() -> function.apply(this)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void applyWithExceptionWrapperWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingFunction<Object, Object> function = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(
+				() -> function.apply(this, IllegalStateException::new));
+	}
+
+	@Test
+	void applyWithExceptionWrapperWhenThrowingCheckedExceptionThrowsWrapper() {
+		ThrowingFunction<Object, Object> function = this::throwIOException;
+		assertThatIllegalStateException().isThrownBy(() -> function.apply(this,
+				IllegalStateException::new)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void throwingModifiesThrownException() {
+		ThrowingFunction<Object, Object> function = this::throwIOException;
+		ThrowingFunction<Object, Object> modified = function.throwing(
+				IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> modified.apply(this)).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void ofModifiesThrowException() {
+		ThrowingFunction<Object, Object> function = ThrowingFunction.of(
+				this::throwIOException, IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> function.apply(this)).withCauseInstanceOf(IOException.class);
+	}
+
+	private Object throwIOException(Object o) throws IOException {
+		throw new IOException();
+	}
+
+	private Object throwIllegalArgumentException(Object o) throws IOException {
+		throw new IllegalArgumentException();
+	}
+
+}

spring-core/src/test/java/org/springframework/util/function/ThrowingSupplierTests.java

@@ -0,0 +1,88 @@
+/*
+ * 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.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+
+/**
+ * Tests for {@link ThrowingSupplier}.
+ *
+ * @author Phillip Webb
+ * @since 6.0
+ */
+class ThrowingSupplierTests {
+
+	@Test
+	void getWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingSupplier<Object> supplier = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(supplier::get);
+	}
+
+	@Test
+	void getWhenThrowingCheckedExceptionThrowsWrapperRuntimeException() {
+		ThrowingSupplier<Object> supplier = this::throwIOException;
+		assertThatExceptionOfType(RuntimeException.class).isThrownBy(
+				supplier::get).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void getWithExceptionWrapperWhenThrowingUncheckedExceptionThrowsOriginal() {
+		ThrowingSupplier<Object> supplier = this::throwIllegalArgumentException;
+		assertThatIllegalArgumentException().isThrownBy(
+				() -> supplier.get(IllegalStateException::new));
+	}
+
+	@Test
+	void getWithExceptionWrapperWhenThrowingCheckedExceptionThrowsWrapper() {
+		ThrowingSupplier<Object> supplier = this::throwIOException;
+		assertThatIllegalStateException().isThrownBy(
+				() -> supplier.get(IllegalStateException::new)).withCauseInstanceOf(
+						IOException.class);
+	}
+
+	@Test
+	void throwingModifiesThrownException() {
+		ThrowingSupplier<Object> supplier = this::throwIOException;
+		ThrowingSupplier<Object> modified = supplier.throwing(
+				IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> modified.get()).withCauseInstanceOf(IOException.class);
+	}
+
+	@Test
+	void ofModifiesThrowException() {
+		ThrowingSupplier<Object> supplier = ThrowingSupplier.of(
+				this::throwIOException, IllegalStateException::new);
+		assertThatIllegalStateException().isThrownBy(
+				() -> supplier.get()).withCauseInstanceOf(IOException.class);
+	}
+
+	private Object throwIOException() throws IOException {
+		throw new IOException();
+	}
+
+	private Object throwIllegalArgumentException() throws IOException {
+		throw new IllegalArgumentException();
+	}
+
+}