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;
}
}