mainservlet.java

《j2me开发精解〉（詹健飞）CD-rom附带源码。用netbeans

package com.ch6.post;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class MainServlet extends HttpServlet {
    
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        //设置响应的Content-Type
        response.setContentType("application/octet-stream");
        ModelFacade facade = new ModelFacade();
        try{
            int contentLength = handleCall(facade, response.getOutputStream(), request.getInputStream());
            response.setContentLength(contentLength);
        }catch(ApplicationException ex){
            ex.printStackTrace();
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        }
    }
    
    private int handleCall(ModelFacade facade,OutputStream os,InputStream is) throws IOException,ApplicationException{
        DataInputStream dis = new DataInputStream(is);
        DataOutputStream result = new DataOutputStream(os);
        try{
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            DataOutputStream dos = new DataOutputStream(baos);
            //读取客户端发送的第一个字节、代表客户端要进行的操作
            byte op = dis.readByte();
            System.out.println(op);
            
            switch(op){
                case MessageConstants.OP_POST_ARTICLE:{
                    postArticle(facade,dis,dos);
                    break;
                }
                case 100:{
                    print(facade,dis,dos);
                    break;
                }
                
                case 101:{
                    result.writeUTF("192.168.0.3");
                    result.writeInt(1290);
                    break;
                }
                default:{
                    result.writeInt(MessageConstants.UNKNOWN_OP);
                }
            }
            dos.flush();
            //操作成功，首先把ERROR_NONE写入到输出流其次是数据
            byte[] data = baos.toByteArray();
            result.writeInt(MessageConstants.ERROR_NONE);
            result.write(data, 0, data.length);
            
        }catch(ModelException ex){
            //抛出异常，将ERROR_MODEL_EXCEPTION和异常写入输出流
            result.writeInt(MessageConstants.ERROR_MODEL_EXCEPTION);
            ex.serialize(result);
        }
        return result.size();
    }
    //发表文章
    private void postArticle(ModelFacade facade,DataInputStream dis,DataOutputStream dos) throws IOException,ApplicationException,ModelException{
        Article article = Article.deserialize(dis);
        facade.postArticle(article);
        return;
    }
    
    private void print(ModelFacade facade,DataInputStream dis,DataOutputStream dos) throws IOException,ApplicationException,ModelException{
        System.out.println(dis.readUTF());
        System.out.println(dis.readInt());
        return;
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    public String getServletInfo() {
        return "Short description";
    }
}