HttpClient获取并解析JSON数据

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<String,String> paramsHashMap = new HashMap<String, String>();
    	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<String, String> paramsHashMap, String encoding) {
		JSONObject resultJsonObject = null;
		List<NameValuePair> nameValuePairArrayList = new ArrayList<NameValuePair>();
		// 将传过来的参数填充到List<NameValuePair>中
		if (paramsHashMap != null && !paramsHashMap.isEmpty()) {
			for (Map.Entry<String, String> entry : paramsHashMap.entrySet()) {
				nameValuePairArrayList.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
			}
		}
		
		UrlEncodedFormEntity entity = null;
		try {
			// 利用List<NameValuePair>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;
	}
}