Java tutorial
/* * Copyright 2002-2018 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.remoting.support; import java.io.Serializable; import java.lang.reflect.InvocationTargetException; import org.springframework.lang.Nullable; /** * Encapsulates a remote invocation result, holding a result value or an exception. * Used for HTTP-based serialization invokers. * * <p>This is an SPI class, typically not used directly by applications. * Can be subclassed for additional invocation parameters. * * <p>Both {@link RemoteInvocation} and {@link RemoteInvocationResult} are designed * for use with standard Java serialization as well as JavaBean-style serialization. * * @author Juergen Hoeller * @since 1.1 * @see RemoteInvocation */ public class RemoteInvocationResult implements Serializable { /** Use serialVersionUID from Spring 1.1 for interoperability. */ private static final long serialVersionUID = 2138555143707773549L; @Nullable private Object value; @Nullable private Throwable exception; /** * Create a new RemoteInvocationResult for the given result value. * @param value the result value returned by a successful invocation * of the target method */ public RemoteInvocationResult(@Nullable Object value) { this.value = value; } /** * Create a new RemoteInvocationResult for the given exception. * @param exception the exception thrown by an unsuccessful invocation * of the target method */ public RemoteInvocationResult(@Nullable Throwable exception) { this.exception = exception; } /** * Create a new RemoteInvocationResult for JavaBean-style deserialization * (e.g. with Jackson). * @see #setValue * @see #setException */ public RemoteInvocationResult() { } /** * Set the result value returned by a successful invocation of the * target method, if any. * <p>This setter is intended for JavaBean-style deserialization. * Use {@link #RemoteInvocationResult(Object)} otherwise. * @see #RemoteInvocationResult() */ public void setValue(@Nullable Object value) { this.value = value; } /** * Return the result value returned by a successful invocation * of the target method, if any. * @see #hasException */ @Nullable public Object getValue() { return this.value; } /** * Set the exception thrown by an unsuccessful invocation of the * target method, if any. * <p>This setter is intended for JavaBean-style deserialization. * Use {@link #RemoteInvocationResult(Throwable)} otherwise. * @see #RemoteInvocationResult() */ public void setException(@Nullable Throwable exception) { this.exception = exception; } /** * Return the exception thrown by an unsuccessful invocation * of the target method, if any. * @see #hasException */ @Nullable public Throwable getException() { return this.exception; } /** * Return whether this invocation result holds an exception. * If this returns {@code false}, the result value applies * (even if it is {@code null}). * @see #getValue * @see #getException */ public boolean hasException() { return (this.exception != null); } /** * Return whether this invocation result holds an InvocationTargetException, * thrown by an invocation of the target method itself. * @see #hasException() */ public boolean hasInvocationTargetException() { return (this.exception instanceof InvocationTargetException); } /** * Recreate the invocation result, either returning the result value * in case of a successful invocation of the target method, or * rethrowing the exception thrown by the target method. * @return the result value, if any * @throws Throwable the exception, if any */ @Nullable public Object recreate() throws Throwable { if (this.exception != null) { Throwable exToThrow = this.exception; if (this.exception instanceof InvocationTargetException) { exToThrow = ((InvocationTargetException) this.exception).getTargetException(); } RemoteInvocationUtils.fillInClientStackTraceIfPossible(exToThrow); throw exToThrow; } else { return this.value; } } }