使用jackson制作json工具类

梦里梦外; 2022-05-13 06:33 113阅读 0赞

## pom文件： ##

<dependency>
          <groupId>org.codehaus.jackson</groupId>
          <artifactId>jackson-core-asl</artifactId>
          <version>1.9.13</version>
        </dependency>
        <dependency>
          <groupId>org.codehaus.jackson</groupId>
          <artifactId>jackson-mapper-asl</artifactId>
          <version>1.9.13</version>
        </dependency>
    
        <dependency>
          <groupId>org.apache.commons</groupId>
          <artifactId>commons-lang3</artifactId>
          <version>3.5</version>
        </dependency>

## JSON工具类： ##

@Slf4j
    public class JsonMapper { 
    
        private static ObjectMapper objectMapper = new ObjectMapper();
    
        static {
            // config 如果是空的字段，直接忽略
            objectMapper.disable(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES);
            objectMapper.configure(SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS, false);
            objectMapper.setFilters(new SimpleFilterProvider().setFailOnUnknownId(false));
            objectMapper.setSerializationInclusion(JsonSerialize.Inclusion.NON_EMPTY);
        }
    
        public static <T> String obj2String(T src) {
            if (src == null) {
                return null;
            }
            try {
                return src instanceof String ? (String) src : objectMapper.writeValueAsString(src);
            } catch (Exception e) {
                log.warn("parse object to String exception, error:{}", e);
                return null;
            }
            //objectMapper.writeValueAsString(src) 对象转换成json的string
        }
    
        public static <T> T string2Obj(String src, TypeReference<T> typeReference) {
            if (src == null || typeReference == null) {
                return null;
            }
            try {
                return (T) (typeReference.getType().equals(String.class) ? src : objectMapper.readValue(src, typeReference));
            } catch (Exception e) {
                log.warn("parse String to Object exception, String:{}, TypeReference<T>:{}, error:{}", src, typeReference.getType(), e);
                return null;
            }
            //objectMapper.readValue(src, typeReference) 把string src转换成对象
        }
    }

*  JsonMapper.obj2String(module)