httpproxyhandler.java

该HttpProxy用于从Applet或Swing界面中访问Ejb和服务端的JavaBean。

/**
 * @作者： 胡俊
 * @创建时间： 2008-03-05
 * @更新时间： 2008-03-05
 * @描述： 
 * 
 */
package com.nari.pmos.proxy.client;

import java.io.*;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLConnection;

/**
 * @author hujun
 * 
 * TODO To change the template for this generated type comment go to Window -
 * Preferences - Java - Code Style - Code Templates
 */
public class HttpProxyHandler implements InvocationHandler {
	private String sessionId = "";

	private String proxyMode = "";

	private String httpURL = "";

	private String usrAccount = "";

	private String usrPwd = "";

	private Class classInterface;

	public HttpProxyHandler(Class classInterface, String sessionId,
			String proxyMode, String httpURL, String account, String pwd) {
		this.classInterface = classInterface;
		this.sessionId = sessionId;
		this.proxyMode = proxyMode;
		this.httpURL = httpURL;
		this.usrAccount = account;
		this.usrPwd = pwd;
	}

	/**
	 * 在序列中发送的数据 接口名称 方法名称 参数的个数 参数数组 String String Integer
	 */

	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		Object r = null;

		Class[] classes = method.getParameterTypes();
		String[] classes_type = new String[classes.length];
		Integer N = new Integer(classes.length);

		int i = 0;
		int n = N.intValue();

		// === 因java无法正确转换 int double，所以作如下处理(原因没有弄清楚) ===
		for (i = 0; i < n; i++) {
			classes_type[i] = "";
			if (classes[i].getName().equals("int")) {
				classes[i] = Integer.class;
				classes_type[i] = "int";
			} else if (classes[i].getName().equals("double")) {
				classes[i] = Double.class;
				classes_type[i] = "double";
			}
			if (classes[i].getName().equals("boolean")) {
				classes[i] = Boolean.class;
				classes_type[i] = "boolean";
			}
		}
		// ===========================================================
		// === 通过http协议访问 servlet ===============================
		try {
			String urlStr = null;
			if (sessionId.length() > 0) {
				urlStr = httpURL + ";jseeeionid=" + sessionId + "?proxymode="
						+ proxyMode;
			} else {
				urlStr = httpURL + "?proxymode=" + proxyMode;
			}
			// System.out.println("httpURL: " + httpURL);
			URL url = new URL(urlStr);
			URLConnection urlconn = url.openConnection();
			// 初始化连接
			urlconn.setUseCaches(false);
			urlconn.setDoOutput(true);
			urlconn.setDoInput(true);

			// 准备，然后向http服务器发送数据（串行化对象）,http服务器由相应的servlet接收并处理
			ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
			ObjectOutputStream out = new ObjectOutputStream(byteOut);

			// System.out.println("开始写调用参数对象......");
			out.writeObject(usrAccount); // user account
			out.writeObject(usrPwd); // user password
			out.writeObject(classInterface.getName()); // 被调用的EJB对应的JNDI名称
			out.writeObject(method.getName()); // 被调用的EJB对应的方法名
			out.writeObject(N); // 增加一个参数表示被调用的EJB方法的参数个数

			// System.out.println("PmosHttpProxyHandler...1");
			// 写入被调用的EJB方法的参数数据
			for (i = 0; i < n; i++) {
				out.writeObject(classes[i]);
			}
			;
			for (i = 0; i < n; i++) {
				out.writeObject(args[i]);
			}
			for (i = 0; i < n; i++) {
				out.writeObject(classes_type[i]);
			}
			// Flush 数据缓冲区
			out.flush();
			byte buf[] = byteOut.toByteArray();

			// System.out.println("PmosHttpProxyHandler...2");

			// 设置属性
			urlconn.setRequestProperty("Content-type",
					"application/octet-stream");
			urlconn.setRequestProperty("Content-length", "" + buf.length);
			// 发送数据
			DataOutputStream dataOut = new DataOutputStream(urlconn
					.getOutputStream());
			dataOut.write(buf);
			dataOut.flush();
			dataOut.close();
			// 等待并读取服务器响应数据
			ObjectInputStream in = new ObjectInputStream(urlconn
					.getInputStream());
			// 读取数据
			// System.out.println("PmosHttpProxyHandler...3");

			N = (Integer) in.readObject();
			if (N.intValue() == 1)
				r = in.readObject();
			in.close();
		} catch (Exception e) {
			System.out
					.println("--- PmosHttpProxyHandler Problem accessing the response text. --- ");
			e.printStackTrace();
			return "--- PmosHttpProxyHandler Problem accessing the response text. --- ";
		}
		// ===========================================================
		return r;
	}

}