Spring框架学习[Spring HTTP调用器实现远程调用](四)
eptor extends RemoteInvocationBasedAccessor
implements MethodInterceptor, HttpInvokerClientConfiguration {
private String codebaseUrl;
//HTTP调用请求执行器
private HttpInvokerRequestExecutor httpInvokerRequestExecutor;
public void setCodebaseUrl(String codebaseUrl) {
this.codebaseUrl = codebaseUrl;
}
public String getCodebaseUrl() {
return this.codebaseUrl;
}
public void setHttpInvokerRequestExecutor(HttpInvokerRequestExecutor httpInvokerRequestExecutor) {
this.httpInvokerRequestExecutor = httpInvokerRequestExecutor;
}
//获取HTTP调用请求执行器，如果HTTP调用请求执行器没有设置，则使用
//SimpleHttpInvokerRequestExecutor作为HTTP调用请求执行器
public HttpInvokerRequestExecutor getHttpInvokerRequestExecutor() {
if (this.httpInvokerRequestExecutor == null) {
SimpleHttpInvokerRequestExecutor executor = new SimpleHttpInvokerRequestExecutor();
executor.setBeanClassLoader(getBeanClassLoader());
this.httpInvokerRequestExecutor = executor;
}
return this.httpInvokerRequestExecutor;
}
//IoC容器初始化完成回调方法
public void afterPropertiesSet() {
//调用父类的初始化回调方法
super.afterPropertiesSet();
//获取HTTP调用请求执行器
getHttpInvokerRequestExecutor();
}
//拦截器代理对象方法调用入口，拦截器将客户端对远程调用代理的调用封装为
//MethodInvocation对象。
public Object invoke(MethodInvocation methodInvocation) throws Throwable {
if (AopUtils.isToStringMethod(methodInvocation.getMethod())) {
return "HTTP invoker proxy for service URL [" + getServiceUrl() + "]";
}
//创建远程调用对象，封装了远程调用
RemoteInvocation invocation = createRemoteInvocation(methodInvocation);
//远�
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RemoteInvocationResult result = null;
try {
//远程调用入口
result = executeRequest(invocation, methodInvocation);
}
catch (Throwable ex) {
throw convertHttpInvokerAccessException(ex);
}
try {
//返回远程调用结果
return recreateRemoteInvocationResult(result);
}
catch (Throwable ex) {
if (result.hasInvocationTargetException()) {
throw ex;
}
else {
throw new RemoteInvocationFailureException("Invocation of method [" + methodInvocation.getMethod() +
"] failed in HTTP invoker remote service at [" + getServiceUrl() + "]", ex);
}
}
}
//执行远程调用入口
protected RemoteInvocationResult executeRequest(
RemoteInvocation invocation, MethodInvocation originalInvocation) throws Exception {
return executeRequest(invocation);
}
//通过HTTP调用请求执行器执行远程调用
protected RemoteInvocationResult executeRequest(RemoteInvocation invocation) throws Exception {
return getHttpInvokerRequestExecutor().executeRequest(this, invocation);
}
//将远程调用异常转换成Spring异常
protected RemoteAccessException convertHttpInvokerAccessException(Throwable ex) {
if (ex instanceof ConnectException) {
throw new RemoteConnectFailureException(
"Could not connect to HTTP invoker remote service at [" + getServiceUrl() + "]", ex);
}
else if (ex instanceof ClassNotFoundException || ex instanceof NoClassDefFoundError ||
ex instanceof InvalidClassException) {
throw new RemoteAccessException(
"Could not deserialize result from HTTP invoker remote service [" + getServiceUrl() + "]", ex);
}
else {
throw new RemoteAccessException(
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