Jackson 库中的 ObjectMapper

ゝ一世哀愁。 2024-02-20 08:19 48阅读 0赞

## 定义实体类用于序列化的对象 ##

import com.fasterxml.jackson.annotation.JsonProperty;
    
    public class Person {
        
        @JsonProperty("name")
        private String fullName;
        private int age;
    
        public Person() {
        
        }
    
        public Person(String fullName, int age) {
        
            this.fullName = fullName;
            this.age = age;
        }
    
        public String getFullName() {
        
            return fullName;
        }
    
        public void setFullName(String fullName) {
        
            this.fullName = fullName;
        }
    
        public int getAge() {
        
            return age;
        }
    
        public void setAge(int age) {
        
            this.age = age;
        }
    }

## 使用单元测试进行测试 ##

import com.fasterxml.jackson.databind.DeserializationFeature;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import com.fasterxml.jackson.databind.SerializationFeature;
    import org.junit.jupiter.api.BeforeEach;
    import org.junit.jupiter.api.Test;
    
    import java.text.SimpleDateFormat;
    import java.util.Arrays;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    import static org.junit.jupiter.api.Assertions.assertEquals;
    
    public class JacksonSerializationDeserializationTest {
        
        private ObjectMapper objectMapper;
    
        @BeforeEach
        public void setUp() {
        
            // 初始化ObjectMapper，并设置一些配置选项
            objectMapper = new ObjectMapper();
    
            // 忽略未知属性，使序列化/反序列化更灵活
            objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    
            // 设置日期格式，例如：yyyy-MM-dd
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
            objectMapper.setDateFormat(dateFormat);
    
            // 启用日期时间戳格式
            objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        }
    
    
        @Test
        public void testSerializeAndDeserializePerson() throws Exception {
        
            // 创建一个Person对象
            Person originalPerson = new Person("IKUN", 25);
    
            // 序列化Person对象为JSON字符串
            String json = objectMapper.writeValueAsString(originalPerson);
    
            // 反序列化JSON字符串为Person对象
            Person deserializedPerson = objectMapper.readValue(json, Person.class);
    
            // 断言原始对象和反序列化后的对象是否相等
            assertEquals(originalPerson.getFullName(), deserializedPerson.getFullName());
            assertEquals(originalPerson.getAge(), deserializedPerson.getAge());
        }
    
        @Test
        public void testSerializeAndDeserializeList() throws Exception {
        
            // 创建一个List集合
            List<String> stringList = Arrays.asList("Apple", "Banana", "Cherry");
            String json = objectMapper.writeValueAsString(stringList);
    
            // 反序列化JSON字符串为List集合
            List<String> deserializedList = objectMapper.readValue(json, List.class);
    
            // 断言原始集合和反序列化后的集合是否相等
            assertEquals(stringList, deserializedList);
        }
    
        @Test
        public void testSerializeAndDeserializeMap() throws Exception {
        
            // 创建一个Map
            Map<String, Integer> numberMap = new HashMap<>();
            numberMap.put("One", 1);
            numberMap.put("Two", 2);
            String json = objectMapper.writeValueAsString(numberMap);
    
            // 反序列化JSON字符串为Map
            Map<String, Integer> deserializedMap = objectMapper.readValue(json, Map.class);
    
            // 断言原始Map和反序列化后的Map是否相等
            assertEquals(numberMap, deserializedMap);
        }
    }