telefon-zu-Servlet-Kommunikation über Bluetooth mit j2me

Question

Ich habe die einfache J2ME-Anmeldeanwendung erstellt, der Code ist unten.

Es funktioniert perfekt auf dem Emulator, jetzt möchte ich es auf meiner mobilen Anwendung über eine Bluetooth-Verbindung ausführen.Mit anderen Worten, Telefon (J2ME-Anwendung) -PC (Servlet) -Kommunikation über Bluetooth.Brauche Hilfe.

Update Geräteunterstützung Modell: JSR 82 Java-APIs für Bluetooth 1.1.

package hello;

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
import javax.microedition.io.*;
import java.io.*;
import java.util.Vector;

public class MidletServlet extends MIDlet implements CommandListener {
    Display display = null;
    Form form = null;
    TextField tb = null,tb1= null;
    String str = null;
    String url = "http://localhost:8084/j2metest/getText";
    Command backCommand = new Command("Back", Command.BACK, 0);
    Command submitCommand = new Command("Submit", Command.OK, 2);
    Command exitCommand = new Command("Exit", Command.STOP, 3);
    private Test test;

    public MidletServlet() {}

    public void startApp() throws MIDletStateChangeException {
        display = Display.getDisplay(this);
        form = new Form("Request Servlet");
        tb = new TextField("Username: ","",30,TextField.ANY );
        tb1 = new TextField("Password: ","",30,TextField.ANY);
        form.append(tb);
        form.append(tb1);
        form.addCommand(submitCommand);
        form.addCommand(exitCommand);
        form.setCommandListener(this);
        display.setCurrent(form);
    }

    public void pauseApp() {}

    public void destroyApp(boolean unconditional) {}

    public void commandAction(Command c, Displayable d) {
        if (c == exitCommand) {
            destroyApp(true);
            notifyDestroyed();
        } else if (c == backCommand) {
            display.setCurrent(form);
        } else if (c == submitCommand) {
            test  = new Test(this);
            test.start();
            test.getServlet(tb.getString(),tb1.getString());
        }
    }
    class Test implements Runnable {
        MidletServlet midlet;
        private Display display;
        String pass;
        String user;

        public Test(MidletServlet midlet) {
            this.midlet = midlet;
            display = Display.getDisplay(midlet);
        }

        public void start() {
            Thread t = new Thread(this);
            t.start();
        }

        public void run() {
            StringBuffer sb = new StringBuffer();
            try {
                HttpConnection c = (HttpConnection) Connector.open(url);
                c.setRequestProperty(
                  "User-Agent","Profile/MIDP-2.1, Configuration/CLDC-1.1");

                c.setRequestProperty("Content-Language","en-US");
                c.setRequestMethod(HttpConnection.POST);

                DataOutputStream os =
                        (DataOutputStream)c.openDataOutputStream();

                os.writeUTF(user.trim());
                os.writeUTF(pass.trim());
                os.flush();
                os.close();

                // Get the response from the servlet page.
                DataInputStream is =(DataInputStream)c.openDataInputStream();
                //is = c.openInputStream();
                int ch;
                sb = new StringBuffer();
                while ((ch = is.read()) != -1) {
                    sb.append((char)ch);
                }
                showAlert(sb.toString());
                is.close();
                c.close();
            } catch (Exception e) {
                showAlert(e.getMessage());
            }
        }
                /* This method takes input from user like text and pass
                to servlet */
        public void getServlet(String user,String pass) {
            this.user = user;
            this.pass=pass;
        }

        /* Display Error On screen*/
        private void showAlert(String err) {
            Alert a = new Alert("");
            a.setString(err);
            a.setTimeout(Alert.FOREVER);
            display.setCurrent(a);
        }
    };
}

und das ist mein Servlet-Code

package my;
import java.sql.*;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author vicky
 */
import java.io.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class getText extends HttpServlet {

    public void init() {
    }

    public void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException,
            IOException {

        DataInputStream in =
                new DataInputStream((InputStream)request.getInputStream());

        String user = in.readUTF();
        String pass=in.readUTF();
        String text="";
        try {

            Class.forName("oracle.jdbc.driver.OracleDriver");
                Connection conn= DriverManager.getConnection(
                "jdbc:oracle:thin:@localhost:1521:XE","vicky","1");
                Statement stmt=conn.createStatement();
                ResultSet rs;int f=0;
            rs=stmt.executeQuery("select * from ADMIN");
            //s1=request.getParameter("un");
            //s2=request.getParameter("pw");

            if(user==""||pass=="")
                {
                    text="Username and Password are required for login;";
                }
            else
                {
                //session.setAttribute("uname",s1);
                while(rs.next())
                    {
                    String s3=rs.getString(1);
                    String s4=rs.getString(2);
                    if (user.equals(s3)&&pass.equals(s4))
                        {
                            f=1;
                        }
                }
                if(f==1)
                    {
                    //response.sendRedirect("success.jsp");
                    //out.print(s1);
                text="Login Successful";
                                }
                else
                    {
                     //out.print("ERROR");
                    text="Login Failure";
                                }
                }
          }
        catch(Exception e)
        {
       //out.print("ERROR"+e);
        text="error"+e;
            }
        response.setContentType("text/plain");
        response.setContentLength(text.length());
        PrintWriter out = response.getWriter();

        out.print(text);


        in.close();
        out.close();
        out.flush();
    }

    public void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException,
            IOException {

        doPost(request,response);
    }
}

Answer 1

Ich denke, hier liegt das eigentliche Problem, Ändern Sie einfach Ihre String url = "http://localhost:8084/j2metest/getText"; auf die IP-Adresse seines Computers wie 192.168.1.1 und versuchen Sie es dann erneut.

Der Grund dafür ist, dass beim Ausführen von Java ME-Code auf dem Emulator localhost erkannt wird.Aber jetzt, wenn Sie diese Anwendung auf dem Handy bereitgestellt und mit Bluetooth verbunden haben, greifen Sie von außen auf den Computer zu, sodass localhost in diesem Fall nicht funktioniert.sie müssen seine IP übergeben.