使用Jackson实现对象，json，xml，map的转换

旧城等待， 2022-10-17 04:18 277阅读 0赞

### 使用Jackson实现对象，json，xml，map的转换 ###

*  前言
 *  一、pom文件
 *  二、创建实体类
 *  三、对象、json、xml、map的转换
 *  四、运行结果
 *  五。忽略字段

# 前言 #

使用Jackson实现对象，json，xml，map的互相转换

使用的包

<table> 
 <thead> 
  <tr> 
   <th>包名</th> 
   <th>版本</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>jackson-databind</td> 
   <td>2.12.3</td> 
  </tr> 
  <tr> 
   <td>jackson-dataformat-xml</td> 
   <td>2.12.3</td> 
  </tr> 
 </tbody> 
</table>

# 一、pom文件 #

<dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-core</artifactId>
                <version>2.12.3</version>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-annotations</artifactId>
                <version>2.12.3</version>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.12.3</version>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.dataformat</groupId>
                <artifactId>jackson-dataformat-xml</artifactId>
                <version>2.12.3</version>
            </dependency>

# 二、创建实体类 #

package au.com.koalaclass.pay.paylinx.message.wechatpay;
    
    import au.com.koalaclass.pay.paylinx.message.XmlRequest;
    import com.fasterxml.jackson.annotation.JsonProperty;
    import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
    import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    /** * @Author : luzhiyong * @CreateTime : 2021/6/1 * @Description : **/
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    @JacksonXmlRootElement(localName = "xml")
    public class WechatRateXmlRequest { 
        @JsonProperty(value = "mch_id")
        @JacksonXmlProperty(localName = "mch_id")
        private String mchId;//商户号
    
        @JsonProperty(value = "fee_type")
        @JacksonXmlProperty(localName = "fee_type")
        private String feeType;//货币，如AUD
    }

# 三、对象、json、xml、map的转换 #

对象转换json使用的是ObjectMapper  
对象转换map使用的是XmlMapper

@Test
        public void test2() throws JsonProcessingException { 
            //创建一个对象
            WechatRateXmlRequest wechatRateXmlRequest = new WechatRateXmlRequest();
            //给对象属性赋值
            wechatRateXmlRequest.setMchId("123456");
            wechatRateXmlRequest.setFeeType("AUD");
            //创建ObjectMapper
            ObjectMapper mapper = new ObjectMapper();
            //对象转成json字符
            String json = mapper.writeValueAsString(wechatRateXmlRequest);
            System.out.println("对象转json"+json);
            //json字符串转对象
            WechatRateXmlRequest xmlRequest = mapper.readValue(json, WechatRateXmlRequest.class);
            System.out.println("json字符串转对象"+xmlRequest.toString());
            //json转map
            Map mp = mapper.readValue(json, Map.class);
            System.out.println("json转map"+mp);
            XmlMapper xmlMapper = new XmlMapper();
            //对象转xml
            String xml = xmlMapper.writeValueAsString(wechatRateXmlRequest);
            System.out.println("对象转xml"+xml);
            //xml转对象
            WechatRateXmlRequest rate = xmlMapper.readValue(xml, WechatRateXmlRequest.class);
            System.out.println("xml转对象"+rate);
            //xml转map
            Map map = xmlMapper.readValue(xml, Map.class);
            System.out.println("xml转map"+map);
    
        }

# 四、运行结果 #

对象转json{ "sign":null,"mch_id":"13231952","fee_type":"AUD"}
    json字符串转对象WechatRateXmlRequest(mchId=13231952, feeType=AUD)
    json转map{ sign=null, mch_id=13231952, fee_type=AUD}
    对象转xml<xml><sign/><mch_id>13231952</mch_id><fee_type>AUD</fee_type></xml>
    xml转对象WechatRateXmlRequest(mchId=13231952, feeType=AUD)
    xml转map{ sign=, mch_id=13231952, fee_type=AUD}

# 五。忽略字段 #

@JsonIgnoreProperties(ignoreUnknown = true)  
将这个注解写在类上之后，就会忽略类中不存在的字段

这个注解还可以指定要忽略的字段。使用方法如下：  
@JsonIgnoreProperties(\{ “internalId”, “secretKey” \})