gson and json

Posted 2021-02-01 uuhh

gson强大的地方是可以反解析

//从文件过去json
File file = new File(GsonT.class.getResource("json.sjon").getFile());
String s = FileUtils.readFileToString(file);
Gson gson = new Gson();
Diaosi diaosi = gson.fromJson(s, Diaosi.class);
//gson转换日期格式

File file = new File(GsonT.class.getResource("json.sjon").getFile());
String s = FileUtils.readFileToString(file);
Gson gson = new GsonBuilder().setDateFormat("yyyy-MM-dd").create();
Diaosi diaosi1 = gson.fromJson(s, Diaosi.class);

System.out.println(diaosi1.getBirthDay().toString());
System.out.println(diaosi1.getMajor());
System.out.println(diaosi1.getMajor().getClass());//java.util.Array

System.out.println(diaosi1.getMajor().getClass());//修改diaosi类的major类型为Set.gson会自动转换成java.util.Set

//最基本的json操作
JSONObject json = new JSONObject();
Object nullObj=null;
json.put("name","王小二");

//gonsBuilder格式

GsonBuilder gb=new GsonBuilder();
        gb.setPrettyPrinting();
        gb.setFieldNamingStrategy(new FieldNamingStrategy() {
            public String translateName(Field field) {
              if(field.getName().equals("name")){
                return "Name";
              }
                return field.getName();
            }
        });
        Gson gson1 = gb.create();
        System.out.println(gson1.toJson(diaosi));


//获取数组jsonarray

 File file = new File(JsonObjectOne.class.getResource("/j.json").getFile());

        String content = FileUtils.readFileToString(file);
        JSONObject jsonObject = new JSONObject(content);
        if(!jsonObject.isNull("name")){

        }
        if(!jsonObject.isNull("nickname")){

        }
        JSONArray jsonArray = jsonObject.getJSONArray("major");
        for(int i=0;i<jsonArray.length();i++){
            String m=(String)jsonArray.get(i);
        }