Android之解析JSON格式数据

1.JSON格式分类

1.获取"数组形式"的JSON数据

数据形式：[{"stuNo":100,"name":"小明"},{"stuNo":101,"name":"小张"}]数据为数组形式，直接用 android框架

2.获取"对象形式"的JSON数据

 返回的数据形式是一个Object类型，所以可以直接转换成一个Object

数据形式：{"total":2,"success":true,"appList":[{"id":1,"name":"小猪"},{"id":2,"name":"小猫"}]}

3.获取类型复杂的JSON数据

数据形式： 

{"name":"小猪", "age":23, "content":{"questionsTotal":2, "questions": [ { "question": "what's your name?",

              "answer": "小猪"}, {"question": "what's your age", "answer": "23"}] } }

2.工具类代码

package demo.xzy.qh.com.jsondemo;

import android.util.Log;

import org.json.JSONArray;
import org.json.JSONObject;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
* 从internet获取json数据，并转换为list
* json处理工具类
*/
public class DealJsonUtil {

private static final String TAG = "DealJsonUtil";
/**
* 获取"数组形式"的JSON数据
* 数据形式：[{"stuNo":100,"name":"小明"},{"stuNo":101,"name":"小张"}]数据为数组形式
*
* @param path 网页json路径
*/
public static List<Map<String, String>> getJSONArray(String path) throws Exception {
String json = null;
List<Map<String, String>> list = new ArrayList<>();
Map<String, String> map = null;
URL url = new URL(path);
/**HttpURLConnection对象,从网络中获取网页数据*/
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
/**设置超时时间为5秒*/
conn.setConnectTimeout(5 * 1000);
/**HttpURLConnection是通过HTTP协议请求path路径的，所以需要设置请求方式,可以不设置，因为默认为GET*/
conn.setRequestMethod("GET");
/**判断请求是否成功，成功时请求码为200，否则失败*/
if (conn.getResponseCode() == 200) {
/**获取数据输入流*/
InputStream is = conn.getInputStream();
/**把输入流转换成字符数组*/
byte[] data = readStream2Array(is);
/**字符数组转换成字符串*/
json = new String(data);
/**数据形式：[{"stuNo":100,"name":"小明"},{"stuNo":101,"name":"小张"}]数据为数组形式，直接用 android框架  */
JSONArray jsonArray = new JSONArray(json);
for (int i = 0; i < jsonArray.length(); i++) {
/**获取每条数据中的对象*/
JSONObject item = jsonArray.getJSONObject(i);
/**注意key值要一致*/
String stuNo = item.getString("stuNo");
String name = item.getString("name");

map = new HashMap<>();
map.put("stuNo", stuNo);
map.put("name", name);

list.add(map);
}
}
return list;
}

/**
* 获取"对象形式"的JSON数据，
* 数据形式：{"total":2,"success":true,"appList":[{"id":1,"name":"小猪"},{"id":2,"name":"小猫"}]}
* 返回的数据形式是一个Object类型，所以可以直接转换成一个Object
*
* @param path 网页json路径
* @return 返回List
* @throws Exception
*/
public static List<Map<String, Object>> getJSONObject(String path) throws Exception {
List<Map<String, Object>> list = new ArrayList<>();
try {
Map<String, Object> map = null;
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(5 * 1000); // 单位是毫秒，设置超时时间为5秒
conn.setRequestMethod("GET");
if (conn.getResponseCode() == 200) {
InputStream is = conn.getInputStream();
byte[] data = readStream2Array(is);
String json = new String(data);
/** 数据形式：{"total":2,"success":true,"appList":[{"id":1,"name":"小猪"},{"id":2,"name":"小猫"}]}
* 返回的数据形式是一个Object类型，所以可以直接转换成一个Object*/
JSONObject jsonObject = new JSONObject(json);
boolean success = jsonObject.getBoolean("success");
if (success) {
/**json对象中有一个数组数据，又可以使用getJSONArray获取数组*/
JSONArray jsonArray = jsonObject.getJSONArray("appList");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject item = jsonArray.getJSONObject(i);
int id = item.optInt("id");
String name = item.getString("name");

map = new HashMap<>();

map.put("id", id);
map.put("name", name);
list.add(map);
}
} else {
Log.i(TAG, "getJSONObject: success:" + success);
}

}
} catch (Exception e) {
e.printStackTrace();
}
return list;
}

/**
* 获取类型复杂的JSON数据
* 数据形式： {"name":"小猪", "age":23, "content":{"questionsTotal":2, "questions": [ { "question": "what's your name?",
* "answer": "小猪"}, {"question": "what's your age", "answer": "23"}] } }
*
* @param path 网页json路径
*/
public static List<Map<String, Object>> getComplexJSON(String path) throws Exception {
List<Map<String, Object>> list = new ArrayList<>();
Map<String, Object> map = null;
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(5 * 1000);
conn.setRequestMethod("GET");
if (conn.getResponseCode() == 200) {
InputStream is = conn.getInputStream();
byte[] data = readStream2Array(is);
String json = new String(data);
/**
* 数据形式： {"name":"小猪", "age":23, "content":{"questionsTotal":2, "questions": [ { "question": "what's your name?",
* "answer": "小猪"}, {"question": "what's your age", "answer": "23"}] } }
*/
JSONObject jsonObject = new JSONObject(json);

String name = jsonObject.getString("name");
int age = jsonObject.getInt("age");

Log.i("abc", "name:" + name + " | age:" + age);

JSONObject contentObject = jsonObject.getJSONObject("content");
String questionsTotal = contentObject.getString("questionsTotal");

Log.i(TAG, "getComplexJSON: questionsTotal:" + questionsTotal);

JSONArray contentArray = contentObject.getJSONArray("questions");
for (int i = 0; i < contentArray.length(); i++) {
JSONObject item = contentArray.getJSONObject(i);
String question = item.getString("question");
String answer = item.getString("answer");

map = new HashMap<>();
map.put("question", question);
map.put("answer", answer);

list.add(map);
}
}
return list;
}

/**
* 把输入流转换成字符数组
*/
public static byte[] readStream2Array(InputStream inputStream) throws Exception {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while ((len = inputStream.read(buffer)) != -1) {
bout.write(buffer, 0, len);
}
bout.close();
inputStream.close();
return bout.toByteArray();
}
}