java 关于xml的注解，自动生成xml文件 - @XML***

       用的是jdk自带的javax.xml.bind.JAXBContext将对象和xml字符串进行相互转换。

       如果对要生成的 xml 格式有点些许的限制，就会对生成xml的对象就需要进行些许控制，控制对象的一个最可行的办法就是用注解。

       （jdk 1.6 api： http://www.cs.uic.edu/~mcpc/Java_Docs/api/index.html?javax/xml/bind/JAXBContext.html）

 

       比较常用的几个：

       @XmlRootElement：根节点

       @XmlAttribute：该属性作为xml的attribute

       @XmlElement：该属性作为xml的element，且可以增加属性(name="NewElementName")，那么生成的xml串的elment的标签是NewElementName

        示例：    

       

package test;

import java.io.StringWriter;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;

import test.bean.EleClassA;
import test.bean.EleClassB;
import test.bean.RootClass;

public class Test1 {

	public static void main(String[] args) {
		RootClass rc = new RootClass();
		EleClassA a = new EleClassA();
		EleClassB b = new EleClassB();
		
		a.setAttrC("attrc");
		a.setEleA("eleA");
		a.setEleB("eleB");
		
		b.setAttrPassword("attrPassword");
		b.setAttrUserName("attrUsrName");
		b.setEleCode("eleCode");
		
		rc.setA(a);
		rc.setB(b);
		rc.setRoot("root");
		rc.setRootA("rootA");
		
		
		JAXBContext context;
		try {
			context = JAXBContext.newInstance(RootClass.class);
			Marshaller mar = context.createMarshaller();
			mar.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
			mar.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");
			
			StringWriter writer = new StringWriter();
			
			mar.marshal(rc, writer);
			
			System.out.println(writer.toString());
		} catch (JAXBException e) {
			e.printStackTrace();
		}
		
	}
}


package test.bean;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="rootclass")
public class RootClass {

	private EleClassA a;
	private EleClassB b;
	private String root;
	private String rootA;
	
	@XmlElement(name="eleClassA")
	public EleClassA getA() {
		return a;
	}
	public void setA(EleClassA a) {
		this.a = a;
	}
	@XmlElement(name="EleclassA")
	public EleClassB getB() {
		return b;
	}
	public void setB(EleClassB b) {
		this.b = b;
	}
	public String getRoot() {
		return root;
	}
	public void setRoot(String root) {
		this.root = root;
	}
	public String getRootA() {
		return rootA;
	}
	public void setRootA(String rootA) {
		this.rootA = rootA;
	}
	
}


package test.bean;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;

public class EleClassA {

	private String eleA;
	private String eleB;
	
	private String attrC;

	@XmlElement
	public String getEleA() {
		return eleA;
	}

	public void setEleA(String eleA) {
		this.eleA = eleA;
	}

	@XmlElement(name="elebnewname")
	public String getEleB() {
		return eleB;
	}

	public void setEleB(String eleB) {
		this.eleB = eleB;
	}

	@XmlAttribute()
	public String getAttrC() {
		return attrC;
	}

	public void setAttrC(String attrC) {
		this.attrC = attrC;
	}
	
}


package test.bean;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;

public class EleClassB {

	private String attrUserName;
	private String attrPassword;
	
	private String eleCode;
	
	@XmlAttribute
	public String getAttrUserName() {
		return attrUserName;
	}
	public void setAttrUserName(String attrUserName) {
		this.attrUserName = attrUserName;
	}
	@XmlAttribute(name="password")
	public String getAttrPassword() {
		return attrPassword;
	}
	public void setAttrPassword(String attrPassword) {
		this.attrPassword = attrPassword;
	}
	@XmlElement
	public String getEleCode() {
		return eleCode;
	}
	public void setEleCode(String eleCode) {
		this.eleCode = eleCode;
	}
	
	
}

运行Test1类中main方法，执行结果：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<rootclass>
    <eleClassA attrC="attrc">
        <eleA>eleA</eleA>
        <elebnewname>eleB</elebnewname>
    </eleClassA>
    <EleclassA attrUserName="attrUsrName" password="attrPassword">
        <eleCode>eleCode</eleCode>
    </EleclassA>
    <root>root</root>
    <rootA>rootA</rootA>
</rootclass>