J2ME连接MySQL问题 (Servlet)!!!

mikeng

J2ME连接MySQL问题
(Servlet)!!!

如题。我是个Java新手，请各位高手帮帮忙，急。万分谢意。

1. 我利用LoginServlet.java尝试连接MySQL Database : Working!!!

2. 参考书籍，利用HTTPCommunication.java 连接 Servlets.java (JBoss) ; 修改Servlet.java尝试连接MySQL Database: Failed!!!

以下是我的Code:

HTTPCommunication.java

import javax.microedition.io.*;
import javax.microedition.lcdui.*;
import java.io.*;
import com.shared.*;
public class HTTPCommunication {
private String serviceURL;
private boolean offline = true;
private ProgressObserverUI progressObserverUI = null;
public HTTPCommunication(String serviceURL, ProgressObserverUI progressObserverUI) {
  this.serviceURL = serviceURL;
  this.progressObserverUI = progressObserverUI;
  return;
}
public boolean isOffline() {
  return offline;
}
public void setOffline(boolean offline) {
  this.offline = offline;
  return;
}
public boolean login(String userName, String password) {
  int passed = 0;
  HttpConnection connection = null;
  DataOutputStream outputStream = null;
  DataInputStream inputStream = null;
  try {
   connection = openConnection();
   updateProgress();
   outputStream = openConnectionOutputStream(connection);
   outputStream.writeByte(MessageConstants.OPERATION_LOGIN_USER);
   outputStream.writeUTF(userName);
   outputStream.writeUTF(password);
   outputStream.close();
   updateProgress();
   inputStream = openConnectionInputStream(connection);
   passed = inputStream.readInt();
   System.out.println(passed);
   updateProgress();
  } catch (IOException ioe) {
  } finally {
   closeConnection(connection, outputStream, inputStream);
  }
  if (passed == 1)
   return true;
  else
   return false;
}
private HttpConnection openConnection() throws IOException {
  try {
            HttpConnection connection = (HttpConnection) Connector.open(serviceURL);
   connection.setRequestProperty("User-Agent","Profile/MIDP-2.0 Configuration/CLDC-1.1");
   connection.setRequestProperty("Content-Type","application/octet-stream");
   connection.setRequestMethod(HttpConnection.POST);
   offline = false;
   return connection;
  } catch (IOException ioe) {
   offline = true;
   throw ioe;
  }
}
private DataOutputStream openConnectionOutputStream(HttpConnection connection) throws IOException {
  try {
   return connection.openDataOutputStream();
  } catch (IOException ioe) {
   offline = true;
   throw ioe;
  }
}
private DataInputStream openConnectionInputStream(HttpConnection connection) throws IOException {
  try {
   int responseCode = connection.getResponseCode();
   if (responseCode == HttpConnection.HTTP_OK) {
    DataInputStream inputStream = connection.openDataInputStream();
    return inputStream;
   }
  } catch (IOException ioe) {
   offline = true;
  }
  return null;
}
void closeConnection(HttpConnection connection, DataOutputStream outputStream, DataInputStream inputStream) {
  if (outputStream != null) {
   try {
    outputStream.close();
   } catch (IOException ioe) {
   }
  }
  if (inputStream != null) {
   try {
    inputStream.close();
   } catch (IOException ioe) {
   }
  }
  if (connection != null) {
   try {
    connection.close();
   } catch (IOException ioe) {
   }
  }
  return;
}
protected void updateProgress() {
  if (progressObserverUI != null) {
   if (!progressObserverUI.isStopped()) {
    progressObserverUI.updateProgress();
    return;
   }
  }
}
}

Servlet.java
import java.io.*;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.naming.InitialContext;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.sql.DataSource;
import com.luckysms.shared.*;
    public class LCKServlet extends HttpServlet {
    protected static final String DBName = "java:/DefaultDS";
    private DataSource dataSource;
   
    public void init(ServletConfig config) throws ServletException {
        try {
            InitialContext ic = new InitialContext();
            dataSource = (DataSource) ic.lookup(DBName);
        } catch (Exception e) {
            e.printStackTrace();
            throw new ServletException("init error");
        }
    }  
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        response.setContentType("application/octet-stream");
        InputStream is = request.getInputStream();
        OutputStream os = response.getOutputStream();
      
        DataInputStream call = new DataInputStream(is);
        DataOutputStream result = new DataOutputStream(os);
        byte method = call.readByte();
      
        switch (method) {
        case MessageConstants.OPERATION_LOGIN_USER:
            login(call,result);
            break;
      /**  case MessageConstants.XXX:            
             ......**/
        }
        response.setContentLength(result.size());   
    }         
    private void login(DataInputStream call, DataOutputStream result) throws IOException{
        String username = call.readUTF();
        String password = call.readUTF();        
        System.out.println(username);
        System.out.println(password);
/**Database Query Here**/
        result.writeInt(1);   
        return;
    }
}

mikeng

LoginServlet.java
import java.io.*;
import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class LoginServlet extends HttpServlet{
public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
Connection conn = null;
String nextJSP = null;
try{
Class.forName("com.mysql.jdbc.Driver");
}
catch (ClassNotFoundException e){
throw new ServletException("Unable to load JDBC driver");
}
String userid = (String)request.getParameter("userid");
String password = (String)request.getParameter("password");
   
conn = DriverManager.getConnection ("jdbc:mysql://localhost:3306/dbname", "root", "123456");
Statement stmt = conn.createStatement();
String query = "SELECT *  FROM users WHERE USERNAME =? AND PWD =?";
PreparedStatement ps = conn.prepareStatement(query);
ps.setString(1, userid);
ps.setString(2, password);
ResultSet rs = ps.executeQuery();
if (rs.next()){
StringBuffer fullName = new StringBuffer();
fullName.append(rs.getString(1));
fullName.append(" ");
fullName.append(rs.getString(2));
request.setAttribute ("fullName", fullName.toString());
nextJSP = "/LoginOK.jsp";
}
else{
nextJSP = "/LoginFailed.jsp";
}
conn.close();
ServletConfig config = getServletConfig();
ServletContext context = config.getServletContext();
RequestDispatcher rd = context.getRequestDispatcher(nextJSP);
rd.forward(request, response);
}
catch (SQLException e){
throw new ServletException("SQL call failed");
}
catch (Exception e){
throw new ServletException(e.getMessage());
}
finally{
if (conn != null){
try{
conn.close();
}
catch (SQLException e){
throw new ServletException("connection close failed");
}}}}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
doPost(request, response);
}}

mikeng

要如何修改Servlets.java可以连接MySQL?谢谢

兔仙人

可以 写出来 你 的 ERROR CONSOLE 吗 ？？？？

P.S : 建议你用 DEBUG MODE 。。。。

mikeng

不好意思，我用Netbeans 编写的。我选择Debug --> Debug Main Project
Connected to KVM
KdpDebugTask connecting to debugger 1 ..
KdpDebugTask connecting to debugger 2 ..
KdpDebugTask connecting to debugger 3 ..
KdpDebugTask connecting to debugger 4 ..
KdpDebugTask connecting to debugger 5 ..
KdpDebugTask connecting to debugger 6 ..
Connecting JPDA Debugger to emulator timed out after 6 attempts and 33 seconds.

兔仙人

。。。。。 如果 CONNECT 不到 ， 应该 会 PROMPT EXCEPTION 出来 。。

mikeng

谢谢回复。我的Midlet 如下。它PROMPT “Connection Not FOund”

Thread thread = new Thread() {
                        public void run() {
                                try {

                                        String url = "http://127.0.0.1:8080/Servlet";
                    HTTPCommunication  hc = new HTTPCommunication(url,progressObserverUI);

                                        if(hc.login(userName,password) == true){
   
                        switchDisplayable(null, getMenuList());

                                        }else{
                                        //showErrorAlert("Invalid Username/Password!", display.getCurrent());
                        switchDisplayable(null, getErrorForm(lang.INDEX_HEADER, lang.INDEX_ERRALERT_INVLOGIN));
                                        }
                                        if(progressObserverUI != null)
                                                progressObserverUI = null;
                                } catch (Exception e) {
                    switchDisplayable(null, getErrorForm("", "Connection Not FOund"));
                  }
                        }
                };
                runWithProgress(thread, lang.INDEX_HEADER, false);
        }

mikeng

您可以帮忙修改以上的Servlet.java Connect 去mySQL? Thanks

小陈陈

http://web.bvu.edu/faculty/schwe ... lassForNameDemo.htm

http://www.roseindia.net/servlets/databaseconnectionservlet.shtml

很长。。。
懒惰看。。。。
上面的2个 example 给你。。。。
希望可以帮到你

mikeng

谢谢回复。等我慢慢研究下