android是如何接受web数据的呀

Question

最近在做一个项目，要求android从sqlserver数据库接受数据。已经成功把数据发布到网上，从网上找到相关代码，也能稍微理解一下，但是为什么就是接受不起来呢
不明白到底具体android是如何接受web数据的
下面是代码
package com.example.test2;

import android.app.Activity;
import android.os.Bundle;
import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import android.widget.TextView;

public class MainActivity extends Activity {

private static final String BASE_URL = "http://localhost:8080/thrid/SQLServerTest";  

 private TextView No1;  
 private TextView No2;  
 private TextView No3;     

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

     setupViews();  
 }         
 /** 
  * 初始化 
  */  
 private void setupViews(){  
     No1 = (TextView)findViewById(R.id.textView1);  
     No2 = (TextView)findViewById(R.id.textView2); 
     No3 = (TextView)findViewById(R.id.textView3);

     try {  
         //获取后台返回的Json对象  
         JSONObject mJsonObject = JSONUtil.getJSON(BASE_URL);  
         No1.setText("获取成功!");  //测试
         JSONArray mJsonArray = mJsonObject.getJSONArray("student");              
         JSONObject firstStudent = mJsonArray.getJSONObject(0);  

         JSONObject secondStudent = mJsonArray.getJSONObject(1);

         JSONObject thridStudent = mJsonArray.getJSONObject(2);

         int first_id = firstStudent.getInt("id");
         String first_name = firstStudent.getString("name");
         int first_value = firstStudent.getInt("value");

         int second_id = secondStudent.getInt("id");
         String second_name = secondStudent.getString("name");
         int second_value = secondStudent.getInt("value");

         int thrid_id = thridStudent.getInt("id");
         String thrid_name = thridStudent.getString("name");
         int thrid_value = thridStudent.getInt("value");

         No1.setText("id:"+first_id+",name:"+first_name+",value:"+first_value);  
         No2.setText("id:"+second_id+",name:"+second_name+",value:"+second_value);  
         No3.setText("id:"+thrid_id+",name:"+thrid_name+",value:"+thrid_value);
     } catch (JSONException e) {  
         e.printStackTrace();  
     } catch (Exception e) {  
         e.printStackTrace();  
     }  
 }         

}

---

package com.example.test2;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.UnsupportedEncodingException;

import org.apache.http.HttpEntity;

import org.apache.http.HttpResponse;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.params.BasicHttpParams;

import org.apache.http.protocol.HTTP;

import org.json.JSONException;

import org.json.JSONObject;

import android.util.Log;

/**

• @author frankiewei.

• Json封装的工具类.
  */
  
  public class JSONUtil {

  private static final String TAG = "JSONUtil";

  /**

  • 获取json内容
  • @param url
  • @return JSONArray
  • @throws JSONException
    

  • @throws ConnectionException
    
    */
    
    public static JSONObject getJSON(String url) throws JSONException, Exception {

    return new JSONObject(getRequest(url));
    
    }

    /**

  • 向api发送get请求，返回从后台取得的信息。

  • @param url

  • @return String
    */
    
    protected static String getRequest(String url) throws Exception {
    
    return getRequest(url, new DefaultHttpClient(new BasicHttpParams()));
    
    }

    /**

  • 向api发送get请求，返回从后台取得的信息。

  • @param url

  • @param client

  • @return String
    */
    
    protected static String getRequest(String url, DefaultHttpClient client) throws Exception {
    
    String result = null;
    
    int statusCode = 0;
    
    HttpGet getMethod = new HttpGet(url);
    
    Log.d(TAG, "do the getRequest,url="+url+"");
    
    try {
    
    //getMethod.setHeader("User-Agent", USER_AGENT);

     HttpResponse httpResponse = client.execute(getMethod);  
     //statusCode == 200 正常  
     statusCode = httpResponse.getStatusLine().getStatusCode();  
     Log.d(TAG, "statuscode = "+statusCode);  
     //处理返回的httpResponse信息  
     result = retrieveInputStream(httpResponse.getEntity());  
    

    } catch (Exception e) {
    
    Log.e(TAG, e.getMessage());
    
    throw new Exception(e);
    
    } finally {
    
    getMethod.abort();
    
    }
    
    return result;
    
    }

    /**

  • 处理httpResponse信息,返回String

  • @param httpEntity

  • @return String
    */
    
    protected static String retrieveInputStream(HttpEntity httpEntity) {

    int length = (int) httpEntity.getContentLength();

    if (length < 0) length = 10000;
    
    StringBuffer stringBuffer = new StringBuffer(length);
    
    try {
    
    InputStreamReader inputStreamReader = new InputStreamReader(httpEntity.getContent(), HTTP.UTF_8);
    
    char buffer[] = new char[length];
    
    int count;
    
    while ((count = inputStreamReader.read(buffer, 0, length - 1)) > 0) {
    
    stringBuffer.append(buffer, 0, count);
    
    }
    
    } catch (UnsupportedEncodingException e) {
    
    Log.e(TAG, e.getMessage());
    
    } catch (IllegalStateException e) {
    
    Log.e(TAG, e.getMessage());
    
    } catch (IOException e) {
    
    Log.e(TAG, e.getMessage());
    
    }
    
    return stringBuffer.toString();
    
    }
    
    }
    
    大家知道怎么回事吗

Answer 1

http或socket