反序列化时的 xstream 转换异常答案

【问题标题】：xstream conversion exception on deserialization反序列化时的 xstream 转换异常
【发布时间】：2015-04-17 19:56:38
【问题描述】：

我在使用 xstream 反序列化时遇到以下异常：

com.thoughtworks.xstream.converters.ConversionException：com.config.Service 类型的元素服务未定义为 com.config.Service 类型中的字段

---- 调试信息----

类：com.config.ServiceNServiceConfigurations

必需类型：com.config.Service

路径：/root/services/service

我的 XML 是：

<root>
    <services>
      <service>
        <Id>10</Id>
        <Name>CM</Name>
      </service>
      <service>
        <Id>11</Id>
        <Name>TM</Name>
      </service>
    </services>
    <serviceConfigurations>
      <serviceConfiguration>
        <Key>XYZ</Key>
        <Value>42</Value>
      </serviceConfiguration>
      <serviceConfiguration>
        <Key>ABC</Key>
        <Value>5</Value>
      </serviceConfiguration>
    </serviceConfigurations>
</root>

我创建了一个对应于根标签的类，如下所示：

public class ServiceNServiceConfigurations implements Serializable {
    private List<ServiceConfiguration> serviceConfigurations;
    private List<Service> services;
    // setter and getter methods
}
public class Service implements Serializable {
    private String Id;
    private String Name;
    // setter and getter methods
}
public class ServiceConfiguration implements Serializable{
    private String key; 
    private String value;
    // setter and getter methods
}

在反序列化的测试类中，我写了以下代码：

   XStream xstream = new XStream();
        xstream.alias("root", com.config.ServiceNServiceConfigurations.class);
        xstream.alias("service",com.config.Service.class);
        xstream.alias("serviceConfiguration",com.config.ServiceConfiguration.class);
        xstream.addImplicitCollection(ServiceNServiceConfigurations.class, "services", Service.class);
        xstream.addImplicitCollection(ServiceNServiceConfigurations.class, "serviceConfigurations", ServiceConfiguration.class);
        xstream.aliasField("Key", com.config.ServiceConfiguration.class, "key");
        xstream.aliasField("Value", com.config.ServiceConfiguration.class, "value");
        At below line Conversion Exception is coming
obj = xstream.fromXML(xmlSerialized);

请指导我哪里出错了。

谢谢

【问题讨论】：

标签： java xstream

【解决方案1】：

您应该删除addImplicitCollection 配置，因为您的集合不是隐式的。

XStream xstream = new XStream();
        xstream.alias("root", com.config.ServiceNServiceConfigurations.class);
        xstream.alias("service",com.config.Service.class);
        xstream.alias("serviceConfiguration",com.config.ServiceConfiguration.class);
        xstream.aliasField("Key", com.config.ServiceConfiguration.class, "key");
        xstream.aliasField("Value", com.config.ServiceConfiguration.class, "value");

如果它们是隐式的，您的 xml 将如下所示：

<root>
  <serviceConfiguration>
    <Key>XYZ</Key>
    <Value>42</Value>
  </serviceConfiguration>
  <serviceConfiguration>
    <Key>ABC</Key>
    <Value>5</Value>
  </serviceConfiguration>
  <service>
    <Id>10</Id>
    <Name>CM</Name>
  </service>
  <service>
    <Id>11</Id>
    <Name>TM</Name>
  </service>
</root>

【讨论】：