tbuyextensionsfilter.java

tbuy1.1.5是在netbeans环境下用JSF技术编写的一个论坛tbuy1.1.5是在netbeans环境下用JSF技术编写的一个论坛

/*
 * 作者: 胡李青
 * qq: 31703299
 * Copyright (c) 2007 huliqing
 * 主页 http://www.tbuy.biz/
 * 你可以免费使用该软件，未经许可请勿作用于任何商业目的,如有技术问题请与本人联系！
 */

package biz.tbuy.common.components;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 建立这个类主要是为了帮助自定义组件向客户端中输出相关资源，js or image file...
 * @version 1.0
 * @author huliqing
 * <p><b>qq：</b>31703299
 * <p><b>E-mail：</b><a href="mailto:[e-mail]">[e-mail]</a>
 * <p><b>Homepage：</b><a href="http://www.tbuy.biz/">http://www.tbuy.biz/</a>
 */
public class TbuyExtensionsFilter implements Filter{
    private FilterConfig filterConfig = null;
    /** return /TbuyExtension */ 
    public final static String TBUY_EXT_ID = "/TbuyExtension/";
    /** script request<br>return script*/ 
    public final static String REQUEST_SCRIPT = "script";
    /** lrc request<br>return lrc */ 
    public final static String REQUEST_LRC = "lrc";
    /** img request<br>return img */
    public final static String REQUEST_IMG = "img";
    
    
    
    /** 允许输出的文件类型 */
    private final static List<String> _types = new ArrayList<String>(5);
    static {
        _types.add("js");
        _types.add("lrc");
        _types.add("jpg");
        _types.add("gif");
        _types.add("png");
    }
    
    public void init(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }
    
    /**
     * @param filterConfig The filter configuration object
     */
    public void setFilterConfig(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }
    
    /**
     * Return the filter configuration object for this filter.
     * @return fileterConfig
     */
    public FilterConfig getFilterConfig() {
        return this.filterConfig;
    }

    public void doFilter(ServletRequest request, 
            ServletResponse response, FilterChain chain) 
            throws IOException, ServletException {
        
        HttpServletRequest requestHttp = (HttpServletRequest)request;
        HttpServletResponse responseHttp = (HttpServletResponse)response;
        
        String uri = requestHttp.getRequestURI();
        String uri2 = uri.substring(uri.indexOf(TBUY_EXT_ID) + TBUY_EXT_ID.length());
        String id = uri2.substring(0, uri2.indexOf("="));
        String value = uri2.substring(uri2.indexOf("=") + 1);
        
        // 以下检查客户端来的文件请求类型.
        String type = uri.substring(uri.lastIndexOf(".") + 1);
        if (!_types.contains(type.trim().toLowerCase())) {
            return;
        }
        
        // 1.如果请求的是script资料，则向客户端输出script资源
        // 2.如果请求的是lrc歌词资料，则向客户端输出歌词
        if (id.equals(REQUEST_SCRIPT)) {
            writeScript(responseHttp, value);
        } else if (id.equals(REQUEST_LRC)) {
            writeLrc(responseHttp, value);
        } else if (id.equals(REQUEST_IMG)) {
            writeImg(responseHttp, value);
        }
    }
    
    /**
     * 向客户端输出script资源
     */ 
    private void writeScript(HttpServletResponse response, String path) 
            throws IOException {
        URL url = getClass().getClassLoader().getResource(path);
        URLConnection conn = null;
        InputStream stream = null;
        BufferedReader buffReader = null;
        OutputStreamWriter osw = null;
        String curLine = null;
        try {
            response.setCharacterEncoding("UTF-8");
            osw = new OutputStreamWriter(response.getOutputStream());
            conn = url.openConnection();
            conn.setUseCaches(false);
            stream = conn.getInputStream();
            buffReader = new BufferedReader(new InputStreamReader(stream));
            response.setContentType("text/javascript");
            response.setHeader("Cache-Control", "no-cache");
            while ((curLine = buffReader.readLine()) != null) {
                osw.write(curLine + "\n");
                //System.out.println(curLine);
            }
            osw.close();
            buffReader.close();
        } catch (Exception e) {
            //Elog.log("Exception:TbuyExtensionsFilter:writeScript:" + e.getMessage());
            System.out.println("Exception:" + e.getMessage());
        }
    }
    
    /**
     * 输出歌词资源,由客户端xmlHttp接收
     */ 
    private void writeLrc(HttpServletResponse response, String path) throws IOException {
        InputStreamReader isr = null;
        try {
            if (path.trim().toLowerCase().startsWith("http://")) {
                isr = new InputStreamReader(
                        new URL(path.trim()).openConnection().getInputStream());
            } else {
                isr = new InputStreamReader(
                        new FileInputStream(
                        new File(filterConfig.getServletContext().getRealPath("/") + path)));
            }
        } catch (Exception e) {
            System.out.println("Exception:TbuyExtensionsFilter:" + e.getMessage());
        }
        try {
            BufferedReader buffReader = new BufferedReader(isr);
            response.setCharacterEncoding("UTF-8");
            response.setContentType("text/html");
            PrintWriter pw = response.getWriter();
            String curLine = null;
            while ((curLine = buffReader.readLine()) != null) {
                pw.write(curLine + "\n");
            }
            buffReader.close();
            pw.close();
        } catch (Exception e) {
            System.out.println("Exception:TbuyExtensionsFilter:" + e.getMessage());
        }
    }
    
    private void writeImg(HttpServletResponse response, String path) {
        try {
            String contentType = path.substring(path.lastIndexOf(".") + 1);
            InputStream isr = getClass().
                    getClassLoader().
                    getResource(path).
                    openConnection().
                    getInputStream();
            OutputStream out = response.getOutputStream();
            response.setContentType("image/jpeg");
            byte[] buff = new byte[1024];
            int len;
            while ((len = isr.read(buff, 0, buff.length)) != -1) {
                out.write(buff, 0, len);
                //System.out.println(buff);
            }
            out.flush();
            out.close();
            isr.close();
        } catch (Exception e) {
            System.out.println("Exception:TbuyExtensionFilter:" + e.getMessage());
        }
    }

    public void destroy() {}
}