java-JSON的生成与解析

一：org.json的使用

1.java生成json

1-1：通过JSONObject

public static String createJson() { JSONObject toly = new JSONObject(); toly.put("name", "toly"); toly.put("age", 24); toly.put("birthday", "1994-03-28"); toly.put("isman", false); toly.put("major", new String[]{"java", "c++"}); return toly.toString(); }

1-2：通过Map

public static String createJsonByMap() { Map<String, Object> toly = new HashMap<String, Object>(); toly.put("name", "toly"); toly.put("age", 24); toly.put("birthday", "1994-03-28"); toly.put("isman", false); toly.put("major", new String[]{"java", "c++"}); return new JSONObject(toly).toString(); }

1-3：通过bean

public static String createJsonByBean() { Person toly = new Person(); toly.setAge(24); toly.setName("toly"); toly.setBirthday("1994-03-28"); toly.setIsman(false); List<String> major = new ArrayList<String>(); major.add("java"); major.add("c++"); toly.setMajor(major); return new JSONObject(toly).toString(); }

生成的json格式化后：

{ "age": 24, "birthday": "1994-03-28", "isman": false, "major": [ "java", "c++" ], "name": "toly" }

2.json解析

public static Person parseJson(String json) { JSONObject object = new JSONObject(json); Person toly = new Person(); if (!object.isNull("name")) { toly.setName(object.getString("name")); } if (!object.isNull("age")) { toly.setAge(object.getInt("age")); } if (!object.isNull("birthday")) { toly.setBirthday(object.getString("birthday")); } if (!object.isNull("isman")) { toly.setIsman(object.getBoolean("isman")); } if (!object.isNull("major")) { JSONArray major = object.getJSONArray("major"); ArrayList<String> majors = new ArrayList<String>(); for (int i = 0; i < major.length(); i++) { majors.add((String) major.get(i)); } toly.setMajor(majors); } return toly; }

程序入口：json.Client#main

File file = new File(Client.class.getResource("/toly.json").getFile()); String s = FileUtils.readFileToString(file, "utf-8"); Person toly = JsonParser.parseJson(s); System.out.println(toly);

F:\Intellij_idea\Java\json\src\main\java\toly.json

{ "birthday": "1994-03-28", "major": [ "java", "c++" ], "name": "toly", "isman": false, "age": 24 }

输出：

Person{name='toly', birthday='1994-03-28', age=24, isman=false, major=[java, c++]}

Gson的使用

1.生成json

private static String createJsonByBeanUseGson() { Person toly = new Person(); toly.setAge(24); toly.setName("toly"); toly.setBirthday("1994-03-28"); toly.setIsman(false); List<String> major = new ArrayList<String>(); major.add("java"); major.add("c++"); toly.setMajor(major); return new Gson().toJson(toly); } 注：在bean对象的字段上加上 @SerializedName()注解，可自定义json键名，如: @SerializedName("DiaoSiName") private String name;

结果格式化后：

{ "DiaoSiName": "toly", "age": 24, "birthday": "1994-03-28", "isman": false, "major": [ "java", "c++" ] }

2.json解析：

private static void parseJsonUseGson() throws IOException { File file = new File(org_json.Client.class.getResource("/toly.json").getFile()); String s = FileUtils.readFileToString(file, "utf-8"); Gson gson = new Gson(); Person person = gson.fromJson(s, Person.class); System.out.println(person); }

控制台：

Person{name='null', birthday='1994-03-28', age=24, isman=false, major=[java, c++]}

3.GsonBuilder自定义构造样式

private static String createJsonByBeanUseGson() { Person toly = new Person(); toly.setAge(24); toly.setName("toly"); toly.setBirthday("1994-03-28"); toly.setIsman(false); List<String> major = new ArrayList<String>(); major.add("java"); major.add("c++"); toly.setMajor(major); GsonBuilder gsonBuilder = new GsonBuilder(); gsonBuilder.setPrettyPrinting();//使得输出的json格式化 gsonBuilder.setFieldNamingStrategy(new FieldNamingStrategy() { public String translateName(Field field) { if (field.getName().equals("name")) { return "NAME";//更改字段名 } return "z-"+field.getName(); } }); return gsonBuilder.create().toJson(toly); }

控制台：

{ "NAME": "toly", "z-birthday": "1994-03-28", "z-age": 24, "z-isman": false, "z-major": [ "java", "c++" ] }

解析时的日期处理

private static void parseJsonUseGsonFormateDate() throws IOException { File file = new File(org_json.Client.class.getResource("/toly.json").getFile()); String s = FileUtils.readFileToString(file, "utf-8"); Gson gson = new Gson(); Person_Date person = gson.fromJson(s, Person_Date.class); System.out.println(person.getBirthday()); }

控制台：

Mon Mar 28 00:00:00 CST 1994

转载于:https://www.cnblogs.com/toly-top/p/9782019.html