我有以下 XML:
<licenseSummary>
<dependencies>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.4</version>
<licenses>
<license>
<name>The Apache Software License, Version 2.0</name>
<url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
<distribution>repo</distribution>
</license>
</licenses>
</dependency>
<dependency>
<groupId>somegroup</groupId>
<artifactId>someartifact</artifactId>
<version>2.43.0-SNAPSHOT</version>
<licenses>
<!--No license information available. -->
</licenses>
</dependency>
</dependencies>
</licenseSummary>
当尝试反序列化此 XML 文件时,Jackson 失败,因为 <licenses />
中有注释而不是元素。第二部分 <dependency />
- 存在以下错误的元素:
Cannot deserialize instance of `java.util.ArrayList` out of VALUE_STRING token
我尝试配置 XMLMapper
但这没有帮助:
ObjectMapper xmlMapper = new XmlMapper();
xmlMapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
相关 POJO 如下所示:
public class Dependency {
private String groupId;
private String artifactId;
private String version;
private List<License> licenses = new ArrayList<License>(1);
public String getGroupId() {
return groupId;
}
public void setGroupId(String groupId) {
this.groupId = groupId;
}
public String getArtifactId() {
return artifactId;
}
public void setArtifactId(String artifactId) {
this.artifactId = artifactId;
}
public String getVersion() {
return version;
}
public void setVersion(String version) {
this.version = version;
}
public List<License> getLicenses() {
return licenses;
}
public void setLicenses(List<License> licenses) {
this.licenses = licenses;
}
}
有谁知道我如何忽略该评论。 (顺便说一句:我无法删除 XML 文件中的注释)
jackson-dataformat-xml
版本2.9.4
最佳答案
我最终实现了一个 DeserializationProblemHandler
并将其注册到 xmlMapper
,如下所示:
xmlMapper.addHandler(new LicenceDeserializationProblemHandler());
这是处理程序:
import java.io.IOException;
import java.util.ArrayList;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.deser.DeserializationProblemHandler;
public class LicenceDeserializationProblemHandler extends DeserializationProblemHandler {
@Override
public Object handleUnexpectedToken(DeserializationContext ctxt, Class<?> targetType, JsonToken t, JsonParser p,
String failureMsg) throws IOException {
if(ArrayList.class.isAssignableFrom(targetType) &&
JsonToken.VALUE_STRING.equals(t)) {
// If there is no license a XML-Comment is in the licenses token.
return null;
}else {
return super.handleUnexpectedToken(ctxt, targetType, t, p, failureMsg);
}
}
}
关于java - 当存在 XML 注释而不是元素时,Jackson XML 反序列化失败,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49315576/