android h5返回json怎么解析

发布网友发布时间：2022-05-05 08:24

共1个回答

热心网友时间：2022-04-20 01:53

JSON的定义：

一种轻量级的数据交换格式，具有良好的可读和便于快速编写的特性。业内主流技术为其提供了完整的解决方案（有点类似于正则表达式，获得了当今大部分语言的支持），从而可以在不同平台间进行数据交换。JSON采用兼容性很高的文本格式，同时也具备类似于C语言体系的行为。 – Json.org
JSON Vs XML

1.JSON和XML的数据可读性基本相同
2.JSON和XML同样拥有丰富的解析手段
3.JSON相对于XML来讲，数据的体积小
4.JSON与JavaScript的交互更加方便
5.JSON对数据的描述性比XML较差
6.JSON的速度要远远快于XML.

Tomcat安装：

Tomcat下载地址http://tomcat.apache.org/ 下载后安装，如果成功，启动Tomcat，然后在浏览器里输入:http://localhost:8080/index.jsp，会有个Tomcat首页界面,

新建一个android工程JsonDemo.

[java] view plain
copy

package com.tutor.jsondemo;

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();
//the number of bytes of the content, or a negative number if unknown. If the content length is known but exceeds Long.MAX_VALUE, a negative number is returned.
//length==-1，下面这句报错，println needs a message
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();
}
}