Jaxb实现Java对象与XML之间的转换

Jaxb核心代码：

package ie.swing.xml.parse;import ie.swing.xml.model.Components;import java.io.File;import java.io.FileNotFoundException;import java.io.OutputStream;import javax.xml.bind.JAXBContext;import javax.xml.bind.JAXBElement;import javax.xml.bind.JAXBException;import javax.xml.bind.Marshaller;import javax.xml.bind.Unmarshaller;/** * 组件配置文件解析 *  * @author lile *  */public class ComponentAnalysis {/**根据schema文件生成Java类的命令：xjc.bat -classpath . ie/swing/config/component-1.0.xsd *//** * XML to Java * @param packageName 包名， 如 ie.swing.xml.model * @param xmlPath 要解析的xml文件路径 如 "src/ie/swing/config/component.xml" * @return rootObject 根对象 * @throws JAXBException * @throws FileNotFoundException */public <T> T xml2Java(String packageName, String xmlPath) throws JAXBException, FileNotFoundException {JAXBContext context = JAXBContext.newInstance(packageName);           Unmarshaller unmarshaller = context.createUnmarshaller();           File file = new File(xmlPath);           @SuppressWarnings("unchecked")JAXBElement<T> rootElement = (JAXBElement<T>) unmarshaller.unmarshal(file);           T rootObject = rootElement.getValue();        return rootObject;}/** * Java to XML * @param rootObject 根对象, Xml 根标签对应的对象 * @param out 输出流，该方法将xml数据写入该输出流 * @throws JAXBException */public <T> void java2XML(T rootObject, OutputStream out) throws JAXBException {JAXBContext context = JAXBContext.newInstance(rootObject.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xml头信息marshaller.marshal(rootObject, out);}/** * 测试运行 * @param args * @throws FileNotFoundException * @throws JAXBException */public static void main(String[] args) throws FileNotFoundException, JAXBException {ComponentAnalysis ca = new ComponentAnalysis();//将Xml解析成Java对象Components cps = ca.xml2Java("ie.swing.xml.model", "src/ie/swing/config/component.xml");//将解析出的Java对象cps解析回Xml并输出到System.outca.java2XML(cps, System.out);}}

 

 

示例xsd schema文件 component-1.0.xsd：

<?xml version="1.0" encoding="UTF-8"?><schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  targetNamespace="http://www.ie168.org/component-1.0" xmlns:tns="http://www.ie168.org/component-1.0" elementFormDefault="qualified">    <element name="components" type="tns:components"></element>    <complexType name="components">    <sequence>    <element ref="tns:component" maxOccurs="unbounded" minOccurs="1"></element>    </sequence>    </complexType>        <element name="component" type="tns:component"></element>        <complexType name="component">    <sequence>    <element ref="tns:rectangle" maxOccurs="unbounded" minOccurs="0"></element>    <element ref="tns:ellipse" maxOccurs="unbounded" minOccurs="0"></element>    </sequence>    <attribute name="name" type="string"></attribute>    <attribute name="text" type="string"></attribute>    </complexType>    <element name="rectangle" type="tns:rectangle"></element>        <complexType name="rectangle">    <attribute name="width" type="float"></attribute>    <attribute name="height" type="float"></attribute>        <attributeGroup ref="tns:point"></attributeGroup>    </complexType>    <element name="ellipse" type="tns:ellipse"></element>        <complexType name="ellipse">    <attribute name="startAngle" type="float"></attribute>    <attribute name="arcAngle" type="float"></attribute>    <attribute name="width" type="float"></attribute>    <attribute name="height" type="float"></attribute>        <attributeGroup ref="tns:point"></attributeGroup>    </complexType>        <attributeGroup name="point">    <attribute name="x" type="float"></attribute>    <attribute name="y" type="float"></attribute>    </attributeGroup></schema>

 

 

示例xml文件: component.xml

<?xml version="1.0" encoding="utf-8" ?><ie:components xmlns="http://www.w3.org/2001/XMLSchema"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"                 xmlns:ie="http://www.ie168.org/component-1.0"               xsi:schemaLocation="http://www.ie168.org/component-1.0 component-1.0.xsd"><ie:component name="rectangle" text="矩形"><ie:rectangle height="100" width="100" x="0" y="0"/></ie:component><ie:component name="ellipse" text="椭圆"><ie:ellipse arcAngle="360" startAngle="0" height="100" width="100" x="0" y="0"/></ie:component></ie:components>

 

运行之前先用JDK自带的命令：

    xjc.bat -classpath . 包名/component-1.0.xsd

根据schema文件生成对应的Java类