使用Jackson XmlMapper将XML反序列化为POJO

Z时代
2024-01-10
分类：问答

使用Jackson XmlMapper注释，如何将XML反序列化为pojo？

<?xml version="1.0" encoding="UTF-8"?>
<open>
   <creds priv="write" type="internal">
      <user>Username1</user>
      <client_token>abcplaudzrbcy37c</client_token>
      <client_secret>0cxDE3LE0000=</client_secret>
   </creds>
   <creds priv="read" type="internal">
      <user>Username1</user>
      <client_token>123plaudzrbcy37c</client_token>
      <client_secret>0cxDE3LE1234=</client_secret>
   </creds>
   <creds priv="none" type="internal">
      <user>Username1</user>
      <client_token>000plaudzrbcy37c</client_token>
      <client_secret>0cxDE3LEabcd=</client_secret>
   </creds>
</open>

我试图使用这样的东西：

@JacksonXmlRootElement(localName = "Open")
public class OpenCredentials {
    @JacksonXmlProperty(localName = "Credentials")
    private Credentials[] credentials;
}
class Credentials {
    @JacksonXmlProperty(isAttribute = true)
    private String priv;
    @JacksonXmlProperty(isAttribute = true)
    private String type;
    @JacksonXmlProperty(localName = "Creds")
    private Creds[] creds;
}
class Creds {
    @JacksonXmlText(value = true)
    private String user;
    @JacksonXmlText(value = true)
    private String client_token;
    @JacksonXmlText(value = true)
    private String client_secret;
}

当我尝试使用XmlMapper的readValue（）时，出现以下错误：

com.fasterxml.jackson.databind.JsonMappingException: Duplicate property '' for [simple type, class com.company.data.utils.api.Creds]
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:268)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:243)

回答：

您的POJO课程与您的课程不符XML。结构比您想象的要简单。请参见以下示例：

@JacksonXmlRootElement(localName = "open")
class OpenCredentials {
    @JacksonXmlProperty(localName = "creds")
    @JacksonXmlElementWrapper(useWrapping = false)
    private Credentials[] credentials;
    //getters, setters, toString
}
class Credentials {
    @JacksonXmlProperty(isAttribute = true)
    private String priv;
    @JacksonXmlProperty(isAttribute = true)
    private String type;
    private String user;
    @JacksonXmlProperty(localName = "client_token")
    private String clientToken;
    @JacksonXmlProperty(localName = "client_secret")
    private String clientSecret;
    //getters, setters, toString
}

简单用法：

XmlMapper mapper = new XmlMapper();
OpenCredentials openCredentials = mapper.readValue(XML, OpenCredentials.class);
System.out.println(openCredentials);

上面的程序打印（适用于您XML）：

OpenCredentials{credentials=[Credentials{priv='write', type='internal', user='Username1', client_token='abcplaudzrbcy37c', client_secret='0cxDE3LE0000='}, Credentials{priv='read', type='internal', user='Username1', client_token='123plaudzrbcy37c', client_secret='0cxDE3LE1234='}, Credentials{priv='none', type='internal', user='Username1', client_token='000plaudzrbcy37c', client_secret='0cxDE3LEabcd='}]}

也可以看看：