android 开发时 线程老是出问题，求帮忙看看怎么回事

Question

跟着书上一步步来的，不知道哪里有问题，tomcat打开了，却连接不了服务器，似乎不执行线程里的东西

package com.example.administrator.myapplication;

import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

public class MainActivity extends AppCompatActivity {

private EditText nickname;
private EditText content;
private String result="";
private TextView resultTV;
private Handler handler;
private Button button;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    nickname=(EditText)findViewById(R.id.nickname);
    content=(EditText)findViewById(R.id.content);
    resultTV=(TextView)findViewById(R.id.resultTV);

    button=(Button)findViewById(R.id.button);

    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if("".equals(content.getText().toString())){
                Toast.makeText(MainActivity.this,"请输入要发表的内容",Toast.LENGTH_SHORT).show();
                return;
            }

            new Thread(new Runnable() {
                public void run() {
                    send();
                    handler=new Handler(){
                        public void handleMessage(Message msg){
                            if (result!=null){
                                resultTV.setText(result);
                                content.setText("");
                                nickname.setText("");
                            }
                            super.handleMessage(msg);
                        }
                    };

                    Message m=handler.obtainMessage();
                    handler.sendMessage(m);
                }
            }).start();
        }
    });
}

public void send(){
    String target="http://10.0.2.2:8080/test/co.jsp";
    URL url;

    try {
        url=new URL(target);
        try {
            HttpURLConnection urlConn=(HttpURLConnection)url.openConnection();
            urlConn.setRequestMethod("POST");
            urlConn.setDoInput(true);
            urlConn.setDoOutput(true);
            urlConn.setInstanceFollowRedirects(true);
            urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
            DataOutputStream out=new DataOutputStream(urlConn.getOutputStream());

            String param="nickname="+ URLEncoder.encode(nickname.getText().toString(),"utf-8")+"&content="+URLEncoder.encode(content.getText().toString(),"utf-8");
            out.writeBytes(param);
            out.flush();
            out.close();

            if(urlConn.getResponseCode()==HttpURLConnection.HTTP_OK){
                InputStreamReader in =new InputStreamReader(urlConn.getInputStream());
                BufferedReader buffer=new BufferedReader(in);
                String inputLine=null;
                while ((inputLine=buffer.readLine())!=null){
                    result+=inputLine+"\n";
                }
                in.close();
            }
            urlConn.disconnect();

        } catch (MalformedURLException e) {
            e.printStackTrace();
        }

    } catch (IOException e) {
        e.printStackTrace();
    }
}

}

这是我jsp的内容

<%@page contentType="text/html;charset=utf-8" language="java" %>
<%
String content=request.getParameter("content");
String nickname=request.getParameter("nickname");
if(content!=null&&nickname!=null){
nickname=new String(nickname.getBytes("iso-8859-1"),"utf-8");
content=new String(content.getBytes("iso-8859-1"),"utf-8");
String date=new java.util.Date().toLocaleString();
%>
<%="["+nickname+"]于"+date+"发表一条内容如下："%>
<%=content%>
<%}%>

Answer 1

http://blog.csdn.net/breeze666/article/details/8690022