ObjectMapper的用法 工具类

ObjectMapper的用法 工具类

首先在pom.xml引入

<dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.3</version>
        </dependency>

定义JsonMapper工具类

public class JsonMapper {
 
    private static ObjectMapper objectMapper = new ObjectMapper();
 
    static {
        //config
        objectMapper.disable(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES);//设置在反序列化时忽略在JSON字符串中存在，而在Java中不存在的属性
        objectMapper.configure(SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS, false);//如果是空对象的时候,不抛异常
        objectMapper.setFilters(new SimpleFilterProvider().setFailOnUnknownId(false));
        objectMapper.setSerializationInclusion(JsonSerialize.Inclusion.NON_EMPTY);//属性为null的转换
        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
    }
 
 
    /**
     * 对象转String
     * @param src
     * @param <T>
     * @return
     */
    public static <T> String obj2String(T src){
        if (null == src){
            return null;
        }
        try {
            return src instanceof String ? (String) src:objectMapper.writeValueAsString(src);
        } catch (Exception e) {
            return null;
        }
    }
 
    public static <T> T string2Obj(String src, TypeReference<T> typeReference){
        if(null == src || null == typeReference){
            return null;
        }
        try {
            return (T) (typeReference.getType().equals(String.class) ? src : objectMapper.readValue(src, typeReference));
        } catch (Exception e){
            return null;
        }
    }
 }

测试类：

public static void main(String[] args) {
        SysAcl acl = SysAcl.builder().id(1).name("测试").remark("ceshi").build();
        String a = JsonMapper.obj2String(acl);
        System.out.println(a);
        SysAcl sysAcl = JsonMapper.string2Obj(a, new TypeReference<SysAcl>() {});
        System.out.println(sysAcl.toString());
    }