這篇文章主要為大家介紹了關於JAXB命名空間及前綴的相關資料，文中透過範例程式碼介紹的非常詳細，對大家的學習或工作具有一定的參考學習價值，需要的朋友們下面隨著小編來一起學習學習吧。
本文說明使用jaxb結合dom4j的XMLFilterImpl過濾器實現序列化和反序列化的完全控制
主要實現以下功能
#序列化及反序列化時忽略命名空間
序列化時使用@XmlRootElement(namespace="http:/ /www.lzrabbit.cn")註解作為類別的預設命名空間，徹底消除命名空間前綴
序列化時引用類別有不同命名空間時也不會產生命名空間前綴，而是在特定的xml節點上加入對應的xmlns宣告
😉它的xml節點命名及命名空間需求
同一個套件下有多個命名空間
自訂命名空間前綴
依賴的jar dom4j
<dependency> <groupId>dom4j</groupId> <artifactId>dom4j</artifactId> <version>1.6.1</version> </dependency>
主要原理就是在序列化和反序列化時透過XMLFilterImpl的匿名實作類別實現命名空間及xml節點名稱的控制，實現多樣化需求，廢話不多說直接上程式碼，有更多個人化需求的看官請自行擴展
package com.bjpowernode.util;
import java.io.StringReader;
import java.io.StringWriter;
import javax.xml.bind.*;
import javax.xml.transform.sax.SAXSource;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLFilterImpl;
import org.xml.sax.helpers.XMLReaderFactory;
public class XmlUtil {
public static String toXML(Object obj) {
try {
JAXBContext context = JAXBContext.newInstance(obj.getClass());
Marshaller marshaller = context.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");// //编码格式
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);// 是否格式化生成的xml串
marshaller.setProperty(Marshaller.JAXB_FRAGMENT, false);// 是否省略xm头声明信息
StringWriter out = new StringWriter();
OutputFormat format = new OutputFormat();
format.setIndent(true);
format.setNewlines(true);
format.setNewLineAfterDeclaration(false);
XMLWriter writer = new XMLWriter(out, format);
XMLFilterImpl nsfFilter = new XMLFilterImpl() {
private boolean ignoreNamespace = false;
private String rootNamespace = null;
private boolean isRootElement = true;
@Override
public void startDocument() throws SAXException {
super.startDocument();
}
@Override
public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
if (this.ignoreNamespace) uri = "";
if (this.isRootElement) this.isRootElement = false;
else if (!uri.equals("") && !localName.contains("xmlns")) localName = localName + " xmlns=\"" + uri + "\"";
super.startElement(uri, localName, localName, atts);
}
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
if (this.ignoreNamespace) uri = "";
super.endElement(uri, localName, localName);
}
@Override
public void startPrefixMapping(String prefix, String url) throws SAXException {
if (this.rootNamespace != null) url = this.rootNamespace;
if (!this.ignoreNamespace) super.startPrefixMapping("", url);
}
};
nsfFilter.setContentHandler(writer);
marshaller.marshal(obj, nsfFilter);
return out.toString();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public static <T> T fromXML(String xml, Class<T> valueType) {
try {
JAXBContext context = JAXBContext.newInstance(valueType);
Unmarshaller unmarshaller = context.createUnmarshaller();
// return (T) unmarshaller.unmarshal(new StringReader(xml));
SerializeUtil obj = new SerializeUtil();
XMLReader reader = XMLReaderFactory.createXMLReader();
XMLFilterImpl nsfFilter = new XMLFilterImpl() {
private boolean ignoreNamespace = false;
@Override
public void startDocument() throws SAXException {
super.startDocument();
}
@Override
public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
if (this.ignoreNamespace) uri = "";
super.startElement(uri, localName, qName, atts);
}
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
if (this.ignoreNamespace) uri = "";
super.endElement(uri, localName, localName);
}
@Override
public void startPrefixMapping(String prefix, String url) throws SAXException {
if (!this.ignoreNamespace) super.startPrefixMapping("", url);
}
};
nsfFilter.setParent(reader);
InputSource input = new InputSource(new StringReader(xml));
SAXSource source = new SAXSource(nsfFilter, input);
return (T) unmarshaller.unmarshal(source);
} catch (Exception e) {
throw new RuntimeException(e.getMessage());
}
}
}範例實體類別
import javax.xml.bind.annotation.*;
@XmlRootElement(namespace="http://www.lzrabbit.cn/")
@XmlAccessorType(XmlAccessType.FIELD)
public class ClassA {
private int classAId;
@XmlElement(name="ClassAName")
private String classAName;
@XmlElement(namespace="http://www.cnblogs.com/")
private ClassB classB;
public int getClassAId() {
return classAId;
}
public void setClassAId(int classAId) {
this.classAId = classAId;
}
public String getClassAName() {
return classAName;
}
public void setClassAName(String classAName) {
this.classAName = classAName;
}
public ClassB getClassB() {
return classB;
}
public void setClassB(ClassB classB) {
this.classB = classB;
}
}
import javax.xml.bind.annotation.*;
@XmlAccessorType(XmlAccessType.FIELD)
public class ClassB {
private int ClassBId;
private String ClassBName;
public int getClassBId() {
return ClassBId;
}
public void setClassBId(int classBId) {
this.ClassBId = classBId;
}
public String getClassBName() {
return ClassBName;
}
public void setClassBName(String classBName) {
this.ClassBName = classBName;
}
}呼叫
import com.bjpowernode.util.XmlUtil;
public class MainRun {
/**
* @param args
*/
public static void main(String[] args) {
ClassB classB = new ClassB();
classB.setClassBId(22);
classB.setClassBName("B2");
ClassA classA = new ClassA();
classA.setClassAId(11);
classA.setClassAName("A1");
classA.setClassB(classB);
System.out.println(XmlUtil.toXML(classA));
}
}輸出結果：
##
<?xml version="1.0" encoding="UTF-8"?> <classA xmlns="http://www.lzrabbit.cn/"> <classAId>11</classAId> <ClassAName>A1</ClassAName> <classB xmlns="http://www.cnblogs.com/"> <ClassBId>22</ClassBId> <ClassBName>B2</ClassBName> </classB> </classA>
總結#
以上是Java中JAXB命名空間及前綴的範例詳解的詳細內容。更多資訊請關注PHP中文網其他相關文章！
