android 请求天气API总是不成功

package com.example.weather_demo3;

import android.support.v7.app.ActionBarActivity;
import android.util.Log;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;
import net.sf.json.JSONObject;

public class MainActivity extends ActionBarActivity {
    
       public static final String DEF_CHATSET = "UTF-8";
        public static final int DEF_CONN_TIMEOUT = 30000;
        public static final int DEF_READ_TIMEOUT = 30000;
        public static String userAgent =  "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.66 Safari/537.36";

          
        //配置您申请的KEY
        public static final String APPKEY ="6284e11df2a85c44a1c2bf606237e2bf";
        
        static String result =null;
    
        private static TextView tv1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        tv1=(TextView) findViewById(R.id.textView1);
        getRequest1();
    }
    
    

    //1.根据城市查询天气
    public static void getRequest1(){
       
        String url ="http://op.juhe.cn/onebox/weather/query";//请求接口地址
        Map params = new HashMap();//请求参数
            params.put("cityname","苏州");//要查询的城市，如：温州、上海、北京
            params.put("key",APPKEY);//应用APPKEY(应用详细页查询)
            params.put("dtype","json");//返回数据的格式,xml或json，默认json
  
        try {
            result =net(url, params, "GET");
            JSONObject object = JSONObject.fromObject(result);
            if(object.getInt("error_code")==0){
                System.out.println(object.get("result"));
                tv1.setText(object.get("result").toString()+"----------11111");
                Log.d("true",object.get("result").toString()+"----------11111");
           
            }else{
                System.out.println(object.get("error_code")+":"+object.get("reason"));
                Log.d("wrong", object.get("error_code")+":"+object.get("reason")+"----------->");
                
                tv1.setText(object.get("error_code")+":"+object.get("reason")+"----------->");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
  

  
    /**
     *
     * @param strUrl 请求地址
     * @param params 请求参数
     * @param method 请求方法
     * @return  网络请求字符串
     * @throws Exception
     */
   public static String net(String strUrl, Map params,String method) throws Exception {
            HttpURLConnection conn = null;
            BufferedReader reader = null;
            String rs = null;
            try {
                StringBuffer sb = new StringBuffer();
                if(method==null || method.equals("GET")){
                    strUrl = strUrl+"?"+urlencode(params);
                }
                URL url = new URL(strUrl);
                conn = (HttpURLConnection) url.openConnection();
                if(method==null || method.equals("GET")){
                    conn.setRequestMethod("GET");
                }else{
                    conn.setRequestMethod("POST");
                    conn.setDoOutput(true);
                }
                conn.setRequestProperty("User-agent", userAgent);
                conn.setUseCaches(false);
                conn.setConnectTimeout(DEF_CONN_TIMEOUT);
                conn.setReadTimeout(DEF_READ_TIMEOUT);
                conn.setInstanceFollowRedirects(false);
                conn.connect();
                if (params!= null && method.equals("POST")) {
                    try {
                        DataOutputStream out = new DataOutputStream(conn.getOutputStream());
                        out.writeBytes(urlencode(params));
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
                InputStream is = conn.getInputStream();
                reader = new BufferedReader(new InputStreamReader(is, DEF_CHATSET));
                String strRead = null;
                while ((strRead = reader.readLine()) != null) {
                    sb.append(strRead);
                }
                rs = sb.toString();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (reader != null) {
                    reader.close();
                }
                if (conn != null) {
                    conn.disconnect();
                }
            }
            return rs;
        }
  
    //将map型转为请求参数型
    public static String urlencode(Map<String,String> data) {
        StringBuilder sb = new StringBuilder();
        for (Map.Entry i : data.entrySet()) {
            try {
                sb.append(i.getKey()).append("=").append(URLEncoder.encode(i.getValue()+"","UTF-8")).append("&");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }


}

如上代码，我用聚合数据上的演示代码想请求一个天气数据。结果在

    try {
        result =net(url, params, "GET");
        的时候总是跳不出结果，请问是什么原因

---

网络请求得异步调用哦。

最简单的使用

new Thread(new Runnable() {
    @Override
    public void run() {
        // 得到网络访问结果后，用handler传回主线程做处理
    }
    }).start();

---

请放在子线程中运行，看下权限是否添加

---

Internet权限加了吗