在java项目中，通常会用到json类型的转换，常常需要对 json字符串和对象进行相互转换。
在制作自定义的json转换类之前，先引入以下依赖
<!--json相关工具--><dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-guava</artifactId> <!--google-->
<version>2.5.3</version>
</dependency>
<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>
自定义json工具类的实现:
package com.me.util;import lombok.extern.slf4j.Slf4j;
import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize;
import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
import org.codehaus.jackson.type.TypeReference;
/**
* json转换
*/
@Slf4j
public class JsonMapper {
private static ObjectMapper objectMapper = new ObjectMapper();
static {
// config
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);
}
/**
* 对象转为json字符串
* @param src
* @param <T>
* @return
*/
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",e);
return null;
}
}
/**
* json字符串转为对象
* @param src
* @param typeReference
* @param <T>
* @return
*/
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;
}
}
}
使用：
JSON串转为list类型
对象类型转为JSON串