功能描述
工具類實現了從網絡 url 獲取到 不同數據結構的 json 數據,並轉換成指定的格式。
工具代碼
package com.xzy.util;
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;
/**
* 從internet獲取json數據,並轉換爲 list json 處理工具類
*
* @author xzy
*/
@SuppressWarnings("unused")
public class DealJsonUtils {
/**
* 獲取"數組形式"的JSON數據
* 要解析的數據結構 [{"stuNo":100,"name":"小明"},{"stuNo":101,"name":"小張"}]
*
* @param path 請求 url
* @return list
* @throws Exception 異常處理
*/
public static List<Map<String, String>> getJSONArray(String path) throws Exception {
String json;
List<Map<String, String>> list = new ArrayList<>();
Map<String, String> map;
URL url = new URL(path);
// HttpURLConnection對象,從網絡中獲取網頁數據
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// 設置超時時間爲5秒
conn.setConnectTimeout(5 * 1000);
// HttpURLConnection是通過HTTP協議請求path路徑的,所以需要設置請求方式,可以不設置,因爲默認爲GET
conn.setRequestMethod("GET");
// 判斷請求是否成功,成功時請求碼爲200,否則失敗
if (conn.getResponseCode() == 200) {
// 獲取數據輸入流
InputStream is = conn.getInputStream();
// 把輸入流轉換成字符數組
byte[] data = readStream2Array(is);
// 字符數組轉換成字符串
json = new String(data);
// 數據形式:[{"stuNo":100,"name":"小明"},{"stuNo":101,"name":"小張"}]數據爲數組形式,直接用 android框架
JSONArray jsonArray = new JSONArray(json);
for (int i = 0; i < jsonArray.length(); i++) {
// 獲取每條數據中的對象
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;
}
/**
* 獲取"對象形式"的JSON數據
* 數據形式:{"total":2,"success":true,"appList":[{"id":1,"name":"小豬"},{"id":2,"name":"小貓"}]}
* 返回的數據形式是一個Object類型,所以可以直接轉換成一個Object
*
* @param path 請求 url
* @return 返回List
*/
public static List<Map<String, String>> getJSONObject(String path) throws Exception {
List<Map<String, String>> list = new ArrayList<>();
Map<String, String> map;
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// 單位是毫秒,設置超時時間爲5秒
conn.setConnectTimeout(5 * 1000);
conn.setRequestMethod("GET");
if (conn.getResponseCode() == 200) {
InputStream is = conn.getInputStream();
byte[] data = readStream2Array(is);
String json = new String(data);
JSONObject jsonObject = new JSONObject(json);
// json對象中有一個數組數據,又可以使用getJSONArray獲取數組
JSONArray jsonArray = jsonObject.getJSONArray("appList");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject item = jsonArray.getJSONObject(i);
String id = item.getString("id");
String name = item.getString("name");
map = new HashMap<>();
map.put("id", id);
map.put("name", name);
list.add(map);
}
}
return list;
}
/**
* 獲取類型複雜的JSON數據
*
* 數據形式: {"name":"小豬", "age":23, "content":{"questionsTotal":2, "questions": [ { "question": "what's your name?",
* "answer": "小豬"}, {"question": "what's your age", "answer": "23"}] } }
*
* @param path 請求 url
* @return list
* @throws Exception 異常處理
*/
public static List<Map<String, String>> getComplexJSON(String path) throws Exception {
List<Map<String, String>> list = new ArrayList<>();
Map<String, String> map;
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);
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");
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);
map.put("total", questionsTotal);
list.add(map);
}
}
return list;
}
/**
* 把輸入流轉換成字符數組
*/
private static byte[] readStream2Array(InputStream inputStream) throws Exception {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len;
while ((len = inputStream.read(buffer)) != -1) {
bout.write(buffer, 0, len);
}
bout.close();
inputStream.close();
return bout.toByteArray();
}
}