import java.io.*;import java.net.*;import java.lang.*;import java.util.*;import javax.servlet.*;import javax.servlet.http.*;public class ActionServlet extends HttpServlet {        /** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.     * @param request servlet request     * @param response servlet response     */    protected void processRequest(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {    	response.setContentType("application/octet-stream;charset=UTF-8");        DataInputStream dis = new DataInputStream(request.getInputStream());        DataOutputStream result = new DataOutputStream(response.getOutputStream());        //ByteArrayOutputStream baos = new ByteArrayOutputStream();        //DataOutputStream dos = new DataOutputStream(baos);        byte op = dis.readByte();        //System.out.println(op);        switch(op)        {            case OperateConstants.CHANGE_PWD:            {                UserBean user = UserBean.deserialize(dis);                String newpwd = dis.readUTF();                UserDBBean userdb = new UserDBBean();                boolean isExist = userdb.hasUser(user.getUID());                System.out.println(isExist);                //System.out.println(isExist);                if (isExist){                    UserBean user1 = userdb.getUser(user.getUID());                    boolean isEqual = user.getPWD().equals(user1.getPWD());                   // System.out.println(user1.getPWD());                   // System.out.println(user.getPWD());                   // System.out.println(isEqual);                    if(isEqual){                        //驗證通過，可以修改密碼                       // System.out.println(isEqual);                        user.setPWD(newpwd);                        boolean isSuccess = userdb.updateUser(user);                       // System.out.println(isSuccess);                        if(isSuccess){                            result.writeByte(OperateConstants.CHANGEPWD_SUCCESS);                        }else{                            result.writeByte(OperateConstants.CHANGEPWD_FAIL);                        }                                            }else{                        //驗證失敗                        result.writeByte(OperateConstants.CHANGEPWD_ERROR_PWD);                    }                                                            }else{                    //用戶不存在                    System.out.println("nouser");                    result.writeByte(OperateConstants.CHANGEPWD_NO_USER);                    //result.flush();                }                userdb.releaseConn();                break;            }            case OperateConstants.LOGIN:            {                UserBean user = UserBean.deserialize(dis);                UserDBBean userdb = new UserDBBean();                BookDBBean bookdb = new BookDBBean();                boolean isExist = userdb.hasUser(user.getUID());                //System.out.println(isExist);                if (isExist){                    UserBean user1 = userdb.getUser(user.getUID());                    boolean isEqual = user.getPWD().equals(user1.getPWD());                   // System.out.println(user1.getPWD());                   // System.out.println(user.getPWD());                   // System.out.println(isEqual);                    if(isEqual){                        //驗證通過，可以登陸                       // System.out.println(isEqual);                        //result.writeByte(OperateConstants.LOGIN_SUCCESS);                        boolean hasBookforUser = bookdb.hasBookforUser(user.getUID());                        if(hasBookforUser){                            //有書                            result.writeByte(OperateConstants.LOGIN_SUCCESS_HAS_BOOK);                            List booksforuser = bookdb.getBooksforUser(user.getUID());                            int size = booksforuser.size();                            result.writeInt(size);                            BorrowBean borrow = null;                            for(int j=0;j<size;j++){                                borrow = (BorrowBean)booksforuser.get(j);                                borrow.serialize(result);                            }                        }else{                            //無書                            result.writeByte(OperateConstants.LOGIN_SUCCESS_NO_BOOK);                        }                                                                    }else{                        //驗證失敗                        result.writeByte(OperateConstants.LOGIN_ERROR_PWD);                    }                                                            }else{                    //用戶不存在                    result.writeByte(OperateConstants.LOGIN_NO_USER);                    //result.flush();                }                break;            }            case OperateConstants.SEARCH_BOOK:            {                String bookname = dis.readUTF();                System.out.println(bookname);                BookDBBean bookdb = new BookDBBean();                boolean hasBook = bookdb.hasBook(bookname);                if(hasBook){                    result.writeByte(OperateConstants.SEARCH_HAS_BOOK);                    List books = bookdb.getBooks(bookname);                    result.writeInt(books.size());                    BookBean book = null;                                        for(int i=0;i<books.size();i++){                        book = (BookBean)books.get(i);                        book.serialize(result);                    }                }else{                    result.writeByte(OperateConstants.SEARCH_NO_BOOK);                }                bookdb.releaseConn();                break;            }        }        int size = result.size();        response.setContentLength(size);        result.flush();        result.close();                            }        /** Handles the HTTP <code>GET</code> method.     * @param request servlet request     * @param response servlet response     */    protected void doGet(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {        processRequest(request, response);    }        /** Handles the HTTP <code>POST</code> method.     * @param request servlet request     * @param response servlet response     */    protected void doPost(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {        processRequest(request, response);    }        /** Returns a short description of the servlet.     */    public String getServletInfo() {        return "Short description";    }}