我已经借助xsd（http://www.loc.gov/standards/mods/mods.xsd）中的xjc类生成了。现在，我想读取元素的值，例如xml文件（https://www.loc.gov/standards/mods/v3/mods-userguide-examples.html-第二个示例：数字化书）。我正在动态获取此类的类和方法，这些类和方法返回列表或字符串（getter方法）。我正在获取属性值，而不是元素值。
我的课程：解组
import java.io.File;
import java.util.List;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
public class XMLToObject {
/**
*
* @return List of mods definitions from xml file
*/
public static List convert() {
try {
JAXBContext jaxbContext = JAXBContext.newInstance(ModsCollectionDefinition.class);
Unmarshaller u = jaxbContext.createUnmarshaller();
File f = new File("test.xml");
ModsCollectionDefinition test = (ModsCollectionDefinition)((javax.xml.bind.JAXBElement) u.unmarshal(f)).getValue();
return test.getMods();
} catch (JAXBException e) {
e.printStackTrace();
}
return null;
}
}
用于处理xml数据的类
import java.lang.reflect.*;
import java.util.List;
import org.example.mods.XMLToObject;
/**
* Operations on XML data
*/
public class MODS {
private static List xmlData = XMLToObject.convert();
public static StringBuilder stringBuilder = new StringBuilder();
/**
*
* Get the whole content of the xml file
*
* @return String
*/
public String getXML() {
if(xmlData != null) {
processClass(xmlData);
xmlData = null;
} else {
stringBuilder.append("No file imported!");
}
return stringBuilder.toString();
}
/**
*
* @param list from which will be derived class type
*/
private void processClass(List list) {
for (int i = 0; i < list.size(); i++) {
Class current = castDynamic(list.get(i));
try {
Method[] methods = current.getMethods();
if (methods.length > 0) {
for (int j = 0; j < methods.length; j++) {
if (checkIfMethodReturnsString(methods[j]) && !methods[j].getName().contains("toString")) {
callMethodWhichReturnsString(methods[j], list.get(i));
} else if (checkIfMethodReturnsList(methods[j])) {
callMethodWhichReturnsList(methods[j], list.get(i));
}
}
}
} catch (NullPointerException e) {
stringBuilder.append("No methods in this class!");
}
}
}
/**
*
* @param object from which will be derived class
* @return Class
*/
private Class castDynamic(Object object) {
String className = object.getClass().getName();
try {
Class cls = Class.forName(className);
cls.cast(object);
return cls;
} catch (ClassNotFoundException e) {
return null;
}
}
/**
*
* @param method of the class
* @return String
*/
private String getMethodType(Method method) {
return method.getReturnType().getName();
}
/**
*
* @param method which will be checked according to return type
* @return boolean
*/
private boolean checkIfMethodReturnsString(Method method) {
if(getMethodType(method).contains("String")) {
return true;
} else {
return false;
}
}
/**
*
* @param method which will be checked according to return type
* @return boolean
*/
private boolean checkIfMethodReturnsList(Method method) {
if(getMethodType(method).contains("List")) {
return true;
} else {
return false;
}
}
/**
*
*
* @param method which is invoked
* @param obj on which method is invoked
*/
private void callMethodWhichReturnsList(Method method, Object obj) {
try {
List list = (List) method.invoke(obj);
processClass(list);
} catch (IllegalAccessException | InvocationTargetException ex) {
stringBuilder.append("Invoke exception!");
}
}
/**
* Method returns strings which are attributes but doesn't return values of the elements!
*
* @param method which is invoked
* @param obj on which method is invoked
*/
private void callMethodWhichReturnsString(Method method, Object obj) {
try {
stringBuilder.append(obj.getClass().getSimpleName().replace("Definition", ""));
stringBuilder.append(" - ");
stringBuilder.append(method.getName().replace("get", ""));
stringBuilder.append(": ");
stringBuilder.append(method.invoke(obj));
} catch (IllegalAccessException | InvocationTargetException | IllegalArgumentException ex) {
stringBuilder.append("Invoke exception!");
}
}
}
属性输出：
<mods version="3.3">
Mods-版本：3.3
元素的输出：
<titleInfo>
<title>At Gettysburg, or, What a Girl Saw and Heard of the Battle: A True Narrative</title>
</titleInfo>
TitleInfo-类型：null
TitleInfo-授权：null
TitleInfo-ID：null
TitleInfo-脚本：空
TitleInfo-ContentType：null
TitleInfo-角色：空
TitleInfo-用法：主要
TitleInfo-标题：空
TitleInfo-OtherType：null
TitleInfo-提供：是
TitleInfo-音译：空
TitleInfo-NameTitleGroup：空
TitleInfo-AltRepGroup：空
TitleInfo-TypeBinded：简单
TitleInfo-AltFormat：空
TitleInfo-DisplayLabel：空
TitleInfo-Href：空
TitleInfo-Arcrole：空
TitleInfo-显示：null
TitleInfo-启动：null
TitleInfo-语言：null
TitleInfo-LangBinded：null
TitleInfo-AuthorityURI：空
TitleInfo-ValueURI：空
生成的类TitleInfoDefinition：
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "titleInfoDefinition", propOrder = {
"titleOrSubTitleOrPartNumber"
})
public class TitleInfoDefinition {
@XmlElementRefs({
.......
@XmlElementRef(name = "title", namespace = "http://www.loc.gov/mods/v3", type = JAXBElement.class, required = false),
......
})
protected List<Object> titleOrSubTitleOrPartNumber;
......
@XmlAttribute(name = "title", namespace = "http://www.w3.org/1999/xlink")
protected String title;
.....
* <p>
* Objects of the following type(s) are allowed in the list
* {@link JAXBElement }{@code <}{@link StringPlusLanguage }{@code >}
* {@link JAXBElement }{@code <}{@link StringPlusLanguage }{@code >}
* {@link JAXBElement }{@code <}{@link StringPlusLanguage }{@code >}
* {@link JAXBElement }{@code <}{@link StringPlusLanguage }{@code >}
* {@link NonSort }
*
*
*/
public List<Object> getTitleOrSubTitleOrPartNumber() {
if (titleOrSubTitleOrPartNumber == null) {
titleOrSubTitleOrPartNumber = new ArrayList<Object>();
}
return this.titleOrSubTitleOrPartNumber;
}
......
/**
* Ruft den Wert der title-Eigenschaft ab.
*
* @return
* possible object is
* {@link String }
*
*/
public String getTitle() {
return title;
}
.......
}
我试图直接获得此值：
((JAXBElement)((TitleInfoDefinition)test).getTitleOrSubTitleOrPartNumber().get(0)).getValue();
输出：
gov.loc.mods.v3.StringPlusLanguage@2986fc10
((JAXBElement)((TitleInfoDefinition)test).getTitleOrSubTitleOrPartNumber().get(0)).getName()
输出：
{http://www.loc.gov/mods/v3}标题
我如何获得标题元素的价值？
最佳答案
当您获得StringPlusLanguage类实例时，它对应于您的title元素。这是一种复杂类型，在架构中具有简单的内容：
<xs:complexType name="stringPlusLanguage">
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attributeGroup ref="languageAttributeGroup"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
因此，您可能具有
content或value之类的属性，请检查该类并访问此属性。这将包含元素的文本值。title不仅仅是字符串的原因恰好是因为它在模式中被建模为复杂类型。如果不是xs:string，则将获得字符串值属性。