xy());
//将调用结果写到HTTP响应中
writeRemoteInvocationResult(request, response, result);
}
catch (ClassNotFoundException ex) {
throw new NestedServletException("Class not found during deserialization", ex);
}
}
//从HTTP请求中读取RemoteInvocation远程调用对象入口方法
protected RemoteInvocation readRemoteInvocation(HttpServletRequest request) throws IOException, ClassNotFoundException {
//将从HTTP请求中读取远程调用对象
return readRemoteInvocation(request, request.getInputStream());
}
//从HTTP请求中读取远程调用对象
protected RemoteInvocation readRemoteInvocation(HttpServletRequest request, InputStream is) throws IOException, ClassNotFoundException {
//根据HTTP请求输入流创建对象输入流
ObjectInputStream ois = createObjectInputStream(decorateInputStream(request, is));
try {
//从对象输入流中读取远程调用对象
return doReadRemoteInvocation(ois);
}
finally {
ois.close();
}
}
//获取HTTP请求输入流
protected InputStream decorateInputStream(HttpServletRequest request, InputStream is) throws IOException {
return is;
}
//将远程调用执行结果写到HTTP响应中
protected void writeRemoteInvocationResult(
HttpServletRequest request, HttpServletResponse response, RemoteInvocationResult result) throws IOException {
//设置HTTP响应的内容类型为：application/x-java-serialized-object
response.setContentType(getContentType());
//将远程调用结果写到HTTP响应中
writeRemoteInvocationResult(request, response, result, response.getOutputStream());
}
//将远程调用执行结果写入HTTP响应中
protected void writeRemoteInvocationResult(
HttpServletRequest request, HttpServletResponse response, RemoteInvocationResult result, OutputStream os)
throws IOException {
//获取HTTP响应对象输出流
ObjectOutputStream oos = createObjectOutputStream(decorateOutputStream(request, response, os));
try {
//将远程调用执行结果写到HTTP响应对象输出流中
doWriteRemoteInvocationResult(result, oos);
}
finally {
oos.close();
}
}
//获取HTTP响应对象输入流
protected OutputStream decorateOutputStream(
HttpServletRequest request, HttpServletResponse response, OutputStream os) throws IOException {
return os;
}
}
通过对HttpInvokerServiceExporter的源码分析，我们可以看出，真正执行远程对象调用的是RemoteInvocationResultresult = invokeAndCreateResult(invocation, getProxy());它调用了RemoteInvocationBasedExporter的invokeAndCreateResult方法调用远程目标对象方法，并创建远程调用执行结果，下面我们继续分析执行服务器端远程调用目标对象方法的实现。
9.RemoteInvocationBasedExporter调用服务器目标对象：
RemoteInvocationBasedExporter的invokeAndCreateResult方法调用服务器目标对象方法，RemoteInvocationBasedExporter源码如下：
[java] view plaincopyprint
- 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, Obje