導(dǎo)入maven依賴(lài)

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind --> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.11.2</version> </dependency>

1、java對(duì)象轉(zhuǎn)json

@Testpublic void test01() throws JsonProcessingException { //創(chuàng)建User對(duì)象 User user=new User('admin','1111'); //將user轉(zhuǎn)為json格式 ObjectMapper objectMapper=new ObjectMapper(); String userString=objectMapper.writeValueAsString(user); System.out.println(userString);}

2、writeValue(參數(shù)1，obj)方法介紹

參數(shù)1

File：將obj對(duì)象轉(zhuǎn)換為json字符串，并保存到指定的文件中 writer：將obj對(duì)象轉(zhuǎn)換為json字符串，并將json數(shù)據(jù)填充到字符輸出流中 Outputstream：將obj對(duì)象轉(zhuǎn)換為json字符串，并將json數(shù)據(jù)填充到字節(jié)輸出流中

3、注解介紹

@JsonIgnore：排除屬性，即當(dāng)前注解屬性不轉(zhuǎn)化json @JsonFormat：屬性值的格式化

常用在日期屬性上，eg：@sonFormat(pattern = 'yyyy-MM-dd')

4、json轉(zhuǎn)java對(duì)象

@Testpublic void test02() throws JsonProcessingException { //創(chuàng)建json對(duì)象 String json='{'username':'admin','password':'1111'}'; //將json對(duì)象轉(zhuǎn)為java對(duì)象 ObjectMapper objectMapper=new ObjectMapper(); User user=objectMapper.readValue(json,User.class); System.out.println(user);}

5、集合轉(zhuǎn)json

@Testpublic void test03() throws JsonProcessingException { //創(chuàng)建User對(duì)象 User user=new User('admin','1111'); //存儲(chǔ)User對(duì)象 List<User> userList=new ArrayList<User>(); userList.add(user); userList.add(user); userList.add(user); //集合轉(zhuǎn)json ObjectMapper objectMapper=new ObjectMapper(); String listJson=objectMapper.writeValueAsString(userList); System.out.println(listJson);}

注：map集合的轉(zhuǎn)換和list是一樣的

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