解決跨域訪問問題

    <!-- 解決跨域訪問問題 -->
    <servlet>
        <servlet-name>PoxyServlet</servlet-name>
        <servlet-class>
            com.XXXX.common.servlet.ProxyHandler
        </servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>PoxyServlet</servlet-name>
        <url-pattern>/servlet/PoxyServlet</url-pattern>
    </servlet-mapping>

package com.XXXX.XXXX.servlet;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.Proxy;
import java.net.URL;
import java.net.URLDecoder;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

/**
 * 
 * 網絡跨域代理
 * 
 * @author 
 * @date 
 * **/

public class ProxyHandler extends HttpServlet {

    private static final long serialVersionUID = 8366942161007559486L;

    private static final int BUFFER_SIZE = 8192;

    private static Logger _log = Logger.getLogger(ProxyHandler.class);

    private Proxy proxy = null;

    @Override
    public void init() throws ServletException {
        super.init();
    }

    @SuppressWarnings("deprecation")
    @Override
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        String urlString = request.getQueryString();
        // Add by 
        urlString = URLDecoder.decode(urlString, "UTF-8");
        _log.info("proxy handler get request query full url : " + urlString);
        if (_log.isDebugEnabled()) {
            _log.debug("proxy handler get request query full url : "
                    + urlString);
        }

        if (urlString.startsWith("url=")) {
            urlString = urlString.substring(4);
        }
        if (urlString.indexOf("requestTime") != -1) {
            urlString = urlString.split("requestTime")[0];
            urlString = urlString.substring(0, urlString.length() - 1);
        }
        _log.info("proxy handler get request query url : " + urlString);
        if (_log.isDebugEnabled()) {
            _log.debug("proxy handler get request query url : " + urlString);
        }

        if (urlString.indexOf("?") != -1) {
            urlString = urlString + "&charset=utf-8";
        } else {
            urlString = urlString + "?charset=utf-8";
        }

        HttpURLConnection conn = null;
        InputStream in = null;
        OutputStream out = null;
        try {
            URL httpURL = new URL(urlString);
            if (httpURL.getProtocol().equalsIgnoreCase("HTTP")
                    || httpURL.getProtocol().equalsIgnoreCase("HTTPS")) {
                if (proxy != null) {
                    conn = (HttpURLConnection) httpURL.openConnection(proxy);
                } else {
                    conn = (HttpURLConnection) httpURL.openConnection();
                }

                conn.setRequestMethod("GET");
                conn.setDoOutput(false);
                conn.setDoInput(true);
                conn.setUseCaches(false);

                in = conn.getInputStream();

                response.setContentType("text/xml; charset=UTF-8");
                out = response.getOutputStream();

                byte[] buffer = new byte[BUFFER_SIZE];
                int num = in.read(buffer, 0, BUFFER_SIZE);
                while (num != -1) {
                    _log.info("proxy handler get request output : "
                            + buffer.toString());
                    if (_log.isDebugEnabled()) {
                        _log.debug("proxy handler get request output : "
                                + buffer.toString());
                    }
                    out.write(buffer, 0, num);
                    num = in.read(buffer, 0, BUFFER_SIZE);
                }
                out.flush();
            }
        } catch (IOException e) {
            response.setStatus(500, e.getLocalizedMessage());
            e.printStackTrace();
        } finally {
            if (in != null) {
                in.close();
                in = null;
            }
            if (conn != null) {
                conn.disconnect();
                conn = null;
            }
            if (out != null) {
                out.close();
                out = null;
            }
        }
    }

    @SuppressWarnings("deprecation")
    @Override
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        Document inputDocument = null;
        try {
            SAXReader builder = new SAXReader();
            inputDocument = builder.read(new InputStreamReader(request
                    .getInputStream(), "UTF-8"));
            _log.info("proxy handler post request input document : "
                    + inputDocument.asXML());
            if (_log.isDebugEnabled()) {
                _log.debug("proxy handler post request input document : "
                        + inputDocument.asXML());
            }
        } catch (IOException e) {
            response.setStatus(500, e.getLocalizedMessage());
            e.printStackTrace();
        } catch (DocumentException e) {
            response.setStatus(500, e.getLocalizedMessage());
            e.printStackTrace();
        }

        String urlString = new String(request.getQueryString().getBytes(
                "ISO-8859-1"), "GBK");
        _log.info("proxy handler post request query full url : " + urlString);
        if (_log.isDebugEnabled()) {
            _log.debug("proxy handler post request query full url : "
                    + urlString);
        }

        if (urlString.startsWith("url=")) {
            urlString = urlString.substring(4);
        }
        if (urlString.indexOf("requestTime") != -1) {
            urlString = urlString.split("requestTime")[0];
            urlString = urlString.substring(0, urlString.length() - 1);
        }
        _log.info("proxy handler post request query url : " + urlString);
        if (_log.isDebugEnabled()) {
            _log.debug("proxy handler post request query url : " + urlString);
        }

        HttpURLConnection conn = null;
        InputStream in = null;
        OutputStream out = null;
        try {
            URL httpURL = new URL(urlString);
            if (httpURL.getProtocol().equalsIgnoreCase("HTTP")
                    || httpURL.getProtocol().equalsIgnoreCase("HTTPS")) {
                if (proxy != null) {
                    conn = (HttpURLConnection) httpURL.openConnection(proxy);
                } else {
                    conn = (HttpURLConnection) httpURL.openConnection();
                }

                conn.setRequestMethod("POST");
                // added by 
                conn.setRequestProperty("Content-Type", "application/xml");
                conn.setDoOutput(true);
                conn.setDoInput(true);
                conn.setUseCaches(false);

                OutputStream output = conn.getOutputStream();
                OutputFormat format = OutputFormat.createCompactFormat();
                format.setEncoding("UTF-8");
                XMLWriter writer = new XMLWriter(output, format);
                writer.write(inputDocument);
                output.flush();
                output.close();
                output = null;

                in = conn.getInputStream();

                response.setContentType("text/xml; charset=UTF-8");
                out = response.getOutputStream();

                byte[] buffer = new byte[BUFFER_SIZE];
                int num = in.read(buffer, 0, BUFFER_SIZE);
                while (num != -1) {
                    if (_log.isDebugEnabled()) {
                        _log.debug("proxy handler post request output : "
                                + buffer.toString());
                    }
                    out.write(buffer, 0, num);
                    num = in.read(buffer, 0, BUFFER_SIZE);
                }
                out.flush();
            }
        } catch (IOException e) {
            response.setStatus(500, e.getLocalizedMessage());
            e.printStackTrace();
        } finally {
            if (in != null) {
                in.close();
                in = null;
            }
            if (conn != null) {
                conn.disconnect();
                conn = null;
            }
            if (out != null) {
                out.close();
                out = null;
            }
        }
    }
}