JAXB完毕XML与Java对象的互转

这段时间都老忙了，甚至连周末全部人员都在赶产品的进度，想想连续上12天班，人都有点晕了！

到这会儿最终有点时间。所以准备和大家分享一下JAXB，会不会有人认为有点陌生呢？没事，这里跟大伙儿简单的描写叙述一下：

JAXB（Java Architecture for XML Binding) 是一个业界的标准。是一项能够依据XML Schema产生Java类的技术。

该过程中，JAXB也提供了将XML实例文档反向生成Java对象树的方法。并能将Java对象树的内容又一次写到XML实例文档。从还有一方面来讲，JAXB提供了高速而简便的方法将XML模式绑定到Java表示。从而使得Java开发人员在Java应用程序中能方便地结合XML数据和处理函数。

基本知识就说这么多，咱们来点实际的，准备上代码了：

/**
* @Description:
*
* @Title: Student.java
* @Package com.joyce.bean
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午02:51:41
* @version V2.0
*/
package com.joyce.bean;

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

/**
* @Description: 学生实体类
*
* @ClassName: Student
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午02:51:41
* @version V2.0
*/
@XmlRootElement(name="Student")
public class Student {
/**
* 姓名
*/
private String name;
/**
* 性别
*/
private String sex;
/**
* 年龄
*/
private Integer age;

/**
* @return the name
*/
public String getName() {
return name;
}

/**
* @param name
*            the name to set
*/
@XmlAttribute
public void setName(String name) {
this.name = name;
}

/**
* @return the sex
*/
public String getSex() {
return sex;
}

/**
* @param sex
*            the sex to set
*/
@XmlElement
public void setSex(String sex) {
this.sex = sex;
}

/**
* @return the age
*/
public Integer getAge() {
return age;
}

/**
* @param age
*            the age to set
*/
@XmlElement
public void setAge(Integer age) {
this.age = age;
}

/**
* @param name
* @param sex
* @param age
*/
public Student(String name, String sex, Integer age) {
super();
this.name = name;
this.sex = sex;
this.age = age;
}

/**
*
*/
public Student() {
super();
}
}

再来一个：

/**
* @Description:
*
* @Title: Teacher.java
* @Package com.joyce.bean
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午04:29:23
* @version V2.0
*/
package com.joyce.bean;

import java.util.List;

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

/**
* @Description: 教师实体类
*
* @ClassName: Teacher
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午04:29:23
* @version V2.0
*/
@XmlRootElement(name="Teacher")
public class Teacher {
/**
* 姓名
*/
private String name;
/**
* 性别
*/
private String sex;
/**
* 年龄
*/
private Integer age;
/**
* 学生
*/
private List<Student> students;

/**
* @return the name
*/
public String getName() {
return name;
}

/**
* @param name
*            the name to set
*/
@XmlElement
public void setName(String name) {
this.name = name;
}

/**
* @return the sex
*/
public String getSex() {
return sex;
}

/**
* @param sex
*            the sex to set
*/
@XmlElement
public void setSex(String sex) {
this.sex = sex;
}

/**
* @return the age
*/
public Integer getAge() {
return age;
}

/**
* @param age
*            the age to set
*/
@XmlElement
public void setAge(Integer age) {
this.age = age;
}

/**
* @return the students
*/
public List<Student> getStudents() {
return students;
}

/**
* @param students
*            the students to set
*/
@XmlElement(name="Student")
public void setStudents(List<Student> students) {
this.students = students;
}

/**
*
*/
public Teacher() {
super();
}

/**
* @param name
* @param sex
* @param age
*/
public Teacher(String name, String sex, Integer age) {
super();
this.name = name;
this.sex = sex;
this.age = age;
}

/**
* @param name
* @param sex
* @param age
* @param students
*/
public Teacher(String name, String sex, Integer age, List<Student> students) {
super();
this.name = name;
this.sex = sex;
this.age = age;
this.students = students;
}
}

哈哈，这两个对象一出来。是不是感觉非常熟悉呢。对的，我们这里封装对象，为后面实现Java对象和XML的转换提供非常好的基础。OK。关键代码要来了哈：

/**
* @Description:
*
* @Title: JAXBUtil.java
* @Package com.joyce.util
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午02:54:40
* @version V2.0
*/
package com.joyce.util;

import java.io.ByteArrayOutputStream;
import java.io.File;

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

/**
* @Description:JAXB对象和XML转换util
*
* @ClassName: JAXBUtil
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午02:54:40
* @version V2.0
*/
public class JAXBUtil {

/**
* @Description: 将对象转换为XML
*
* @param obj
* @param beanClass
* @return
* @throws Exception
*
* @Title: JAXBUtil.java
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午04:23:45
* @version V2.0
*/
@SuppressWarnings("unchecked")
public String objectToXmlStr(Object obj, Class beanClass) throws Exception {
JAXBContext context = JAXBContext.newInstance(beanClass);
// 依据上下文获取marshaller对象
Marshaller marshaller = context.createMarshaller();
// 设置编码字符集
marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");
// 格式化XML输出，有分行和缩进
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
// 打印到控制台
marshaller.marshal(obj, System.out);

ByteArrayOutputStream baos = new ByteArrayOutputStream();
marshaller.marshal(obj, baos);
String xmlObj = new String(baos.toByteArray());
return xmlObj.replace(" standalone=\"yes\"", "");
}

/**
* @Description: 将对象转换为XML而且写入文件
*
* @param obj
* @param beanClass
* @param file
* @throws Exception
*
* @Title: JAXBUtil.java
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午04:24:13
* @version V2.0
*/
@SuppressWarnings("unchecked")
public void objectToXmlStr(Object obj, Class beanClass, File file) throws Exception {
JAXBContext context = JAXBContext.newInstance(beanClass);
// 依据上下文获取marshaller对象
Marshaller marshaller = context.createMarshaller();
// 设置编码字符集
marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");
// 格式化XML输出。有分行和缩进
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
// 打印到控制台
marshaller.marshal(obj, System.out);
marshaller.marshal(obj, file);
}

/**
* @Description: XML转换为对象
*
* @param <T>
* @param file
* @param beanClass
* @return
* @throws Exception
*
* @Title: JAXBUtil.java
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午04:24:50
* @version V2.0
*/
@SuppressWarnings("unchecked")
public <T> T xmlStrToObject(File file, Class<T> beanClass) throws Exception {
T bean = beanClass.newInstance();
JAXBContext context = JAXBContext.newInstance(beanClass);
Unmarshaller unmarshaller = context.createUnmarshaller();
bean = (T) unmarshaller.unmarshal(file);
return bean;
}
}

这事实上都是Java中的基础，没事的时候都能够看看Java的源代码和Jdk API等等，会看到你可能想都没有想过的东西！立即上測试类：

/**
* @Description:
*
* @Title: JAXBTest.java
* @Package com.joyce.test
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午03:04:05
* @version V2.0
*/
package com.joyce.test;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import com.joyce.bean.Student;
import com.joyce.bean.Teacher;
import com.joyce.util.JAXBUtil;

/**
* @Description: 測试类
*
* @ClassName: JAXBTest
* @Copyright: Copyright (c) 2014
*
* @author Comsys-LZP
* @date 2014-6-10 下午03:04:05
* @version V2.0
*/
public class JAXBTest {
public static void main(String[] args) {
try {
Teacher teacher = new Teacher("JuanJuan", "女", 22);
Student student = new Student("Joyce.Luo", "男", 21);
Student student2 = new Student("Phang.Law", "男", 18);
JAXBUtil util = new JAXBUtil();
List<Student> stuList = new ArrayList<Student>();
stuList.add(student);
stuList.add(student2);
teacher.setStudents(stuList);
String xmlTeaStr = util.objectToXmlStr(teacher, Teacher.class);
System.out.println("\n包括集合的对象转换为XML：\n" + xmlTeaStr);
String xmlStr = util.objectToXmlStr(student, Student.class);
System.out.println("\n对象转换为XML：\n" + xmlStr);

File file = new File("str.xml");
System.out.println("文件是否存在：" + file.exists());
//			util.objectToXmlStr(student, Student.class, file);
Student stu = util.xmlStrToObject(file, Student.class);
System.out.println("\nXML转换为对象：\n" + stu.getName() + "\t" + stu.getSex() + "\t" + stu.getAge());
} catch (Exception e) {
e.printStackTrace();
}
}
}

结果展示：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Teacher>
<age>22</age>
<name>JuanJuan</name>
<sex>女</sex>
<Student name="Joyce.Luo">
<age>21</age>
<sex>男</sex>
</Student>
<Student name="Phang.Law">
<age>18</age>
<sex>男</sex>
</Student>
</Teacher>

包括集合的对象转换为XML：
<?xml version="1.0" encoding="UTF-8"?>
<Teacher>
<age>22</age>
<name>JuanJuan</name>
<sex>女</sex>
<Student name="Joyce.Luo">
<age>21</age>
<sex>男</sex>
</Student>
<Student name="Phang.Law">
<age>18</age>
<sex>男</sex>
</Student>
</Teacher>

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Student name="Joyce.Luo">
<age>21</age>
<sex>男</sex>
</Student>

对象转换为XML：
<?xml version="1.0" encoding="UTF-8"?>
<Student name="Joyce.Luo">
<age>21</age>
<sex>男</sex>
</Student>

文件是否存在：true

XML转换为对象：
Joyce.Luo	男	21

各位有什么好建议，欢迎提哦！完整资源下载地址：
http://download.csdn.net/download/luo201227/7505479