HttpClient获取并解析JSON数据

下面的类已经说的很明白了

package com.example.testjsonandget;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.params.HttpClientParams;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.json.JSONArray;
import org.json.JSONObject;
 
import android.app.Activity;
import android.os.Bundle;
 
public class MainActivity extends Activity {
    private final String uriString="your url";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //服务器返回的JSON数据
        JSONObject jsonObject=this.getJSONObjectByGet();
        try {
            //从JSON中得到字符串
            String apiString=jsonObject.getString("api");
            String countString=jsonObject.getString("count");
            System.out.println("apiString="+apiString+",countString="+countString);
            //从JSON中得到JSONArray,并且遍历
            JSONArray jsonArray=jsonObject.getJSONArray("data");
            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject everyJsonObject=jsonArray.getJSONObject(i);
                String category_id=everyJsonObject.getString("category_id");
                String category_name=everyJsonObject.getString("category_name");
                String category_rgb=everyJsonObject.getString("category_rgb");
                String category_news_count=everyJsonObject.getString("category_news_count");
                System.out.println("category_id="+category_id+",category_name="+category_name+
                ",category_rgb="+category_rgb+",category_news_count="+category_news_count);
                System.out.println("=====================================================");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    //得到HttpClient
    public HttpClient getHttpClient(){
        HttpParams mHttpParams=new BasicHttpParams();
        //设置网络链接超时
        //即:Set the timeout in milliseconds until a connection is established.
        HttpConnectionParams.setConnectionTimeout(mHttpParams, 20*1000);
        //设置socket响应超时
        //即:in milliseconds which is the timeout for waiting for data.
        HttpConnectionParams.setSoTimeout(mHttpParams, 20*1000);
        //设置socket缓存大小
        HttpConnectionParams.setSocketBufferSize(mHttpParams, 8*1024);
        //设置是否可以重定向
        HttpClientParams.setRedirecting(mHttpParams, true);
         
        HttpClient httpClient=new DefaultHttpClient(mHttpParams);
        return httpClient;
    }
     
    //得到JSONObject(Get方式)
    public JSONObject getJSONObjectByGet(){
        JSONObject resultJsonObject=null;
        if ("".equals(uriString)||uriString==null) {
            return null;
        }
        HttpClient httpClient=this.getHttpClient();
        StringBuilder urlStringBuilder=new StringBuilder(uriString);
        StringBuilder entityStringBuilder=new StringBuilder();
        //利用URL生成一个HttpGet请求
        HttpGet httpGet=new HttpGet(urlStringBuilder.toString());
        BufferedReader bufferedReader=null;
        HttpResponse httpResponse=null;
        try {
            //HttpClient发出一个HttpGet请求
            httpResponse=httpClient.execute(httpGet);      
        } catch (Exception e) {
            e.printStackTrace();
        }
        //得到httpResponse的状态响应码
        int statusCode=httpResponse.getStatusLine().getStatusCode();
        if (statusCode==HttpStatus.SC_OK) {
            //得到httpResponse的实体数据
            HttpEntity httpEntity=httpResponse.getEntity();
            if (httpEntity!=null) {
                try {
                    bufferedReader=new BufferedReader
                    (new InputStreamReader(httpEntity.getContent(), "UTF-8"), 8*1024);
                    String line=null;
                    while ((line=bufferedReader.readLine())!=null) {
                        entityStringBuilder.append(line+"/n");
                    }
                    //利用从HttpEntity中得到的String生成JsonObject
                    resultJsonObject=new JSONObject(entityStringBuilder.toString());
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        return resultJsonObject;
    }
     
    //----------------------------------------以下为POST请求
    //准备进行POST请求的参数，一般而言将这些参数封装在HashMap中
    public JSONObject save(String title, String timelength) throws Exception{
        Map paramsHashMap = new HashMap();
        paramsHashMap.put("title", title);
        paramsHashMap.put("timelength", timelength);
        paramsHashMap.put("method", "save");
        String path = "your url";
        return getJSONObjectByPost(path, paramsHashMap, "UTF-8");
    }
    //得到JSONObject(Post方式)
    //此方法此处未调用测试
    public JSONObject getJSONObjectByPost(String path,Map paramsHashMap, String encoding) {
        JSONObject resultJsonObject = null;
        List nameValuePairArrayList = new ArrayList();
        // 将传过来的参数填充到List中
        if (paramsHashMap != null && !paramsHashMap.isEmpty()) {
            for (Map.Entry entry : paramsHashMap.entrySet()) {
                nameValuePairArrayList.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
            }
        }
         
        UrlEncodedFormEntity entity = null;
        try {
            // 利用List生成Post请求的实体数据
            // 此处使用了UrlEncodedFormEntity!!!
            entity = new UrlEncodedFormEntity(nameValuePairArrayList, encoding);
            HttpPost httpPost = new HttpPost(path);
            // 为HttpPost设置实体数据
            httpPost.setEntity(entity);
            HttpClient httpClient = this.getHttpClient();
            // HttpClient发出Post请求
            HttpResponse httpResponse = httpClient.execute(httpPost);
            if (httpResponse.getStatusLine().getStatusCode() == 200) {
                // 得到httpResponse的实体数据
                HttpEntity httpEntity = httpResponse.getEntity();
                if (httpEntity != null) {
                    try {
                        BufferedReader bufferedReader = new BufferedReader(
                        new InputStreamReader(httpEntity.getContent(),"UTF-8"), 8 * 1024);
                        StringBuilder entityStringBuilder = new StringBuilder();
                        String line = null;
                        while ((line = bufferedReader.readLine()) != null) {
                            entityStringBuilder.append(line + "/n");
                        }
                        // 利用从HttpEntity中得到的String生成JsonObject
                        resultJsonObject = new JSONObject(entityStringBuilder.toString());
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return resultJsonObject;
    }
}