使用Jackson ObjectMapper对Java对象进行序列化与反序列化_java反序列化创建对象json object mapper-优快云博客

本文链接：https://blog.youkuaiyun.com/up_XCY/article/details/123049325

序列化

ObjectMapper mapper = new ObjectMapper();
//序列化
String jsonString = mapper.writeValueAsString(object);

反序列化

readValue()

ObjectMapper mapper = new ObjectMapper();

//单个对象
User user = (User) mapper.readValue(jsonString,User.Class);

//集合对象
//创建集合类型
JavaType javaType = mapper.getTypeFactory().constructCollectionType(List.class,User.class);

List<User> users = (List<User>)mapper.readValue(jsonString,javaType);

readTree()

ObjectMapper mapper = new ObjectMapper();

//单个对象
JsonNode node = mapper.readTree(jsonString);
String userName = node.path("userName").asString();
String age = node.path("age").asInt();
String address = node.path("address").asText();

//集合对象
JsonNode rootNode = mapper.readTree(jsonString);
List<User> list = new ArrayList<>();
for(JsonNode jsonNode:rootNode){
    User user = new User();
    user.setUserName(node.path("userName").asString());
    user.setAge(node.path("age").asInt());
    user.setAddress(node.path("address").asText());
    list.add(user);
}

/*
    node.path()与node.get()具有相同的功能，不同点在于：
    若key不存在，node.get()返回null，node.path()会报missing node。
*/