Spring框架学习[Spring HTTP调用器实现远程调用] - JAVA

ct targetObject) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {

if (logger.isTraceEnabled()) { logger.trace("Executing " + invocation);

} try {

//获取远程调用执行器，由远程调用执行器调用目标对象的方法，即通过 //DefaultRemoteInvocationExecutor了调用目标对象的方法

return getRemoteInvocationExecutor().invoke(invocation, targetObject); }

catch (NoSuchMethodException ex) { if (logger.isDebugEnabled()) {

logger.warn("Could not find target method for " + invocation, ex); }

throw ex; }

catch (IllegalAccessException ex) { if (logger.isDebugEnabled()) {

logger.warn("Could not access target method for " + invocation, ex); }

throw ex; }

catch (InvocationTargetException ex) { if (logger.isDebugEnabled()) {

logger.debug("Target method failed for " + invocation, ex.getTargetException()); }

throw ex; }

} }

public abstract class RemoteInvocationBasedExporter extends RemoteExporter {
	//远程调用执行器
private RemoteInvocationExecutor remoteInvocationExecutor = new DefaultRemoteInvocationExecutor();
public RemoteInvocationExecutor getRemoteInvocationExecutor() {
		return this.remoteInvocationExecutor;
	}
protected RemoteInvocationResult invokeAndCreateResult(RemoteInvocation invocation, Object targetObject) {
		try {
			//调用服务器端目标对象的方法
			Object value = invoke(invocation, targetObject);
			//根据执行结果创建RemoteInvocationResult
			return new RemoteInvocationResult(value);
		}
		catch (Throwable ex) {
			return new RemoteInvocationResult(ex);
		}
	}
//调用目标对象的方法
protected Object invoke(RemoteInvocation invocation, Object targetObject)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
		if (logger.isTraceEnabled()) {
			logger.trace("Executing " + invocation);
		}
		try {
			//获取远程调用执行器，由远程调用执行器调用目标对象的方法，即通过
			//DefaultRemoteInvocationExecutor了调用目标对象的方法
			return getRemoteInvocationExecutor().invoke(invocation, targetObject);
		}
		catch (NoSuchMethodException ex) {
			if (logger.isDebugEnabled()) {
				logger.warn("Could not find target method for " + invocation, ex);
			}
			throw ex;
		}
		catch (IllegalAccessException ex) {
			if (logger.isDebugEnabled()) {
				logger.warn("Could not access target method for " + invocation, ex);
			}
			throw ex;
		}
		catch (InvocationTargetException ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("Target method failed for " + invocation, ex.getTargetException());
			}
			throw ex;
		}
	} 
}

通过上面对RemoteInvocationBasedExporter源码分析我们看到，真正调用目标对象的是DefaultRemoteInvocationExecutor的invoke方法，下面我们继续分析DefaultRemoteInvocationExecutor调用目标对象方法的实现。

10.DefaultRemoteInvocationExecutor调用目标对象的方法实现远程调用：

DefaultRemoteInvocationExecutor用于调用目标对象的指定方法实现远程对象调用服务，其源码如下：

[java] view plaincopyprint

public class DefaultRemoteInvocationExecutor implements RemoteInvocationExecutor { //调用目标对象的方法
public Object invoke(RemoteInvocation invocation, Object targetObject) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException{
Assert.notNull(invocation, "RemoteInvocation must not be null"); Assert.notNull(targetObject, "Target object must not be null");
//调用RemoteInvocation的invoke方法 return invocation.invoke(targetObject);
} }
RemoteInvocation的invoke方法源码如下： public Ob

Spring框架学习[Spring HTTP调用器实现远程调用](十)