package org.jrest4guice.rest;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import org.jrest4guice.client.JRestClient;
import org.jrest4guice.client.ModelMap;
import org.jrest4guice.commons.lang.ClassUtils;
import org.jrest4guice.rest.annotations.RESTful;
import com.google.inject.Singleton;
import com.google.inject.cglib.proxy.Enhancer;
import com.google.inject.cglib.proxy.MethodInterceptor;
import com.google.inject.cglib.proxy.MethodProxy;
/**
*
* @author <a href="mailto:zhangyouqun@gmail.com">cnoss (QQ:86895156)</a>
*
*/
@Singleton
@SuppressWarnings("unchecked")
public class RemoteServiceDynamicProxy implements MethodInterceptor {
private Enhancer enhancer = new Enhancer();
private List<Method> methods;
private List<String> remoteServiceUrls;
private Map<String, String> service_url_relation;
private JRestClient client;
public RemoteServiceDynamicProxy() {
Properties property = new Properties();
try {
property.load(this.getClass().getClassLoader().getResourceAsStream(
"remote.properties"));
} catch (Exception e) {
throw new RuntimeException("在Classpath中无法获取remote.properties文件");
}
Object service_url = property.get("service_url");
if (service_url == null || service_url.toString().trim().equals(""))
throw new RuntimeException(
"在remote.properties文件中没有设置service_url参数值");
String[] urls = service_url.toString().split(",");
this.remoteServiceUrls = Arrays.asList(urls);
this.service_url_relation = new HashMap<String, String>();
this.client = new JRestClient();
}
public <T> T createRemoteService(Class<T> serviceClazz) {
if (!serviceClazz.isAnnotationPresent(RESTful.class)) {
RESTful annotation = (RESTful) serviceClazz
.getAnnotation(RESTful.class);
if (!annotation.remoteable())
throw new RuntimeException(serviceClazz.getName() + "不支持远程调用！");
}
this.methods = ClassUtils.getSortedMethodList(serviceClazz);
enhancer.setSuperclass(serviceClazz);
enhancer.setCallback(this);
return (T) enhancer.create();
}
@Override
public Object intercept(Object instance, Method method, Object[] args,
MethodProxy proxy) throws Throwable {
Object result = null;
Class<?> clazz = method.getDeclaringClass();
RESTful annotation = (RESTful) clazz.getAnnotation(RESTful.class);
String name = annotation.name();
if (name == null || name.trim().equals(""))
name = clazz.getName();
int index = -1;
for (Method m : methods) {
index++;
if (m.equals(method)) {
break;
}
}
ModelMap<String, Object> parameters = new ModelMap<String, Object>();
parameters.put(ModelMap.RPC_ARGS_KEY, args);
String serviceUrl = "";
if (this.service_url_relation.containsKey(clazz.getName())) {
serviceUrl = this.service_url_relation.get(clazz.getName());
serviceUrl += RESTful.REMOTE_SERVICE_PREFIX + "?"
+ RESTful.REMOTE_SERVICE_NAME_KEY + "=" + name + "&"
+ RESTful.REMOTE_SERVICE_METHOD_INDEX_KEY + "=" + index;
try {
result = client.callRemote("http://" + serviceUrl,
RESTful.METHOD_OF_POST, parameters);
} catch (Exception e) {
result = this.try2lookupRemoteServiceAndExcute(result, client,
clazz, name, index, parameters);
}
} else {
result = this.try2lookupRemoteServiceAndExcute(result, client,
clazz, name, index, parameters);
}
return result;
}
private Object try2lookupRemoteServiceAndExcute(Object result,
JRestClient client, Class<?> clazz, String name, int index,
ModelMap<String, Object> parameters) {
String serviceUrl;
for (String surl : this.remoteServiceUrls) {
if (surl.trim().equals(""))
continue;
if (!surl.endsWith("/"))
surl = surl + "/";
serviceUrl = surl + RESTful.REMOTE_SERVICE_PREFIX + "?"
+ RESTful.REMOTE_SERVICE_NAME_KEY + "=" + name + "&"
+ RESTful.REMOTE_SERVICE_METHOD_INDEX_KEY + "=" + index;
try {
result = client.callRemote("http://" + serviceUrl,
RESTful.METHOD_OF_POST, parameters);
this.service_url_relation.put(clazz.getName(), surl);
break;
} catch (Exception e) {
this.service_url_relation.remove(clazz.getName());
}
}
return result;
}
}