Json 数据解析

关于普通Json的大部分解析方法。此博客用于个人复习，欢迎批评

———-原生json解析—-

String json1 = "{\"name\":\"张三\",\"age\":20,\"sex\":\"男\"}";String json3 = "{\"bookname\":\"Java速成\", \"price\":18.6}";JSONObject jsonobj = new JSONObject(json1);Person person = new Person();Book books = new Book();

——解析Object—解析完成后放入实体类中—-

String name = jsonobj.getString("name");int age = jsonobj.getInt("age");String sex = jsonobj.getString("sex");person.setName(name);person.setAge(age);person.setSex(sex);JSONObject jsonobj1 = new JSONObject(json3);String bookname= jsonobj1.getString("bookname");double price = jsonobj1.getDouble("price");books.setBookname(bookname);books.setPrice(price);person.setBooks(books);System.out.println(books);System.out.println(person);/*String json2 = "[\"苹果\",\"栗子\",\"西瓜\"]";

——-解析JsonArray—

JSONArray jsonarray = new JSONArray(json2);List<String> list = new ArrayList<>();for(int i = 0; i<jsonarray.length();i++){    String str = jsonarray.getString(i);    list.add(str);}System.out.println(list);*/

————–JsonObject 和JsonArray 的结合解析

String json4 = "{\"name\":\"李雷\", \"age\":16, \"books\":[{\"bookname\":\"Java入门到放弃\", \"price\":18.9}, {\"bookname\":\"C++领进门，从后门跑了\", \"price\":18.9}, {\"bookname\":\"android这个坑有多深\", \"price\":18.9}]}";JSONObject jsonObject = new JSONObject(json4);Student student = new Student();String name = jsonObject.getString("name");int age = jsonObject.getInt("age");List<Book> book = new ArrayList<>();JSONArray jsonArray = jsonObject.getJSONArray("books");for(int i = 0; i<jsonArray.length();i++){    Book books = new Book();    JSONObject jsonObject2 = jsonArray.getJSONObject(i);    String bookname = jsonObject2.getString("bookname");    double pirce = jsonObject2.getDouble("price");    books.setBookname(bookname);    books.setPicer(pirce);    book.add(books);}student.setName(name);student.setAge(age);student.setList(book);System.out.println(student);

}
———————–下载Url到String—从接口中下载数据存到一个String类型的变量中

// 解析Url为Stringpublic static String getJSONByURL(String urlStr) {InputStream in = null;ByteArrayOutputStream out = null;try {    URL url = new URL(urlStr);    HttpURLConnection conn = (HttpURLConnection) url.openConnection();    in = conn.getInputStream();    out = new ByteArrayOutputStream();    byte[] buffer = new byte[1024];    int len = 0;    while ((len = in.read(buffer)) != -1) {        out.write(buffer, 0, len);    }    byte[] bs = out.toByteArray();    return new String(bs);} catch (Exception e) {    e.printStackTrace();} finally {    if (in != null) {        try {            in.close();        } catch (IOException e) {            e.printStackTrace();        }    }}return null;

——————用Gson解析
首先要创建一个实体类，按照接口里面的格式来创建

String json1 = "{\"name\":\"张三\",\"age\":20,\"sex\":\"男\"}";//PersonString json2 = "[\"苹果\", \"梨子\", \"香蕉\"]";//List<String>String json3 = "{\"bookname\":\"Java速成\", \"price\":18.6}";//解析json1Person ps = new Gson().fromJson(json1, Person.class);System.out.println(ps);//解析json2TypeToken<List<String>> tt = new TypeToken<List<String>>(){};List<String> list = new Gson().fromJson(json2, tt.getType());System.out.println(list);//解析json3Book book = new Gson().fromJson(json3, Book.class);System.out.println(book);String json4 = "{\"name\":\"李雷\", \"age\":16, \"books\":[{\"bookname\":\"Java入门到放弃\", \"price\":18.9}, {\"bookname\":\"C++领进门，从后门跑了\", \"price\":18.9}, {\"bookname\":\"android这个坑有多深\", \"price\":18.9}]}";Student studnent = new Gson().fromJson(json4, Student.class);System.out.println(studnent);

——-一个Gson 和json结合的例子：荔枝新闻解析
——–荔枝新闻的接口，首先要用URl下载这个接口的数据到String 的json中

public static final String URL = "http://litchiapi.jstv.com/api/GetFeeds?column=0&PageSize=10&pageIndex=1&val=100511D3BE5301280E0992C73A9DEC41";public static void main(String[] args) throws JSONException {//下载JSONString json = HttpUtil.getJSONByURL(URL);//解析JSON --> List<New>List<NewsEntity> newsList = new ArrayList<>();JSONObject jsonObject = new JSONObject(json);String isok = jsonObject.getString("status");if(isok.equals("ok")){    //数据请求成功        JSONArray newsJsonArray = jsonObject.getJSONObject("paramz").getJSONArray("feeds");

———先用Json解析，下面再用Gson解析—–实体类一定要按照对应格式创建

    for(int i = 0; i < newsJsonArray.length(); i++){        NewsEntity newsEntity = new NewsEntity();        JSONObject newObject = newsJsonArray.getJSONObject(i);        //解析ID        newsEntity.setId(newObject.getInt("id"));        //解析标题        String subject = newObject.getJSONObject("data").getString("subject");        newsEntity.setSubject(subject);        //解析简介        String summary = newObject.getJSONObject("data").getString("summary");        newsEntity.setSummary(summary);        //解析图片        String cover = newObject.getJSONObject("data").getString("cover");        newsEntity.setCover(cover);        //解析时间        String changed = newObject.getJSONObject("data").getString("changed");        newsEntity.setChanged(changed);        newsList.add(newsEntity);    }

—–下面是荔枝新闻的实体类，按照对应格式，然后选取需要的数据来创建

private int id;// 新闻idprivate String subject;// 新闻标题private String summary;// 新闻简介private String cover;// 新闻图片urlprivate String changed;// 新闻的最后修改时间public int getId() {return id;}public void setId(int id) {this.id = id;}public String getSubject() {return subject;}public void setSubject(String subject) {this.subject = subject;}public String getSummary() {return summary;}public void setSummary(String summary) {this.summary = summary;}public String getCover() {return cover;}public void setCover(String cover) {this.cover = cover;}public String getChanged() {return changed;}public void setChanged(String changed) {this.changed = changed;}@Overridepublic String toString() {return "NewsEntity [id=" + id + ", subject=" + subject + ", summary="        + summary + ", cover=" + cover + ", changed=" + changed + "]";}