Question

我正在尝试在Eclipse EE中编写一个servlet，它向android app.Android app中的client.Client发送一条消息，它有一个从servlet获取消息的Button和一个显示该消息的TextView。但是TextView什么也没显示。这是我的代码：

-servlet：

package nguyen.lan;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;




/**
 * Servlet implementation class HelloServlet
 */
@WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    /**
     * @see HttpServlet#HttpServlet()
     */
    public HelloServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        PrintWriter out=response.getWriter();
        response.setContentType("text/plain");
        out.println("nguyen ngoc lan");
        out.close();
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub


    }
}

-Android app：

package nguyen.lan;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class DemoAndroidActivity extends Activity {
    /** Called when the activity is first created. */
    private TextView myTextView;
    Button mButton;

    String url="http://192.168.1.35:10536/myServlet/HelloServlet";


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myTextView=(TextView) findViewById(R.id.mTextView);
        mButton=(Button) findViewById(R.id.button1);
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               getString(v);       
            }
        });
}
public void getString(View v) {

        InputStream responseStream;
        HttpClient httpClient=new DefaultHttpClient();
        HttpGet httpGet=new HttpGet(url);
        try {
            responseStream=httpClient.execute(httpGet).getEntity().getContent();

            BufferedReader reader=new BufferedReader(new InputStreamReader(responseStream));
            StringBuilder sb=new StringBuilder(); 
            while(reader.readLine()!=null)
            {
                sb.append(reader.readLine());
            }
            String mString=sb.toString();
            myTextView.setText(mString);

        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
}

}

- 我也在AndroidManifest.xml中使用权限INTERNET

无法从android中的servlet获取消息

0 个答案: