XML的操作——JAXB进行Java对象和XML之间的转换

JAXB(Java Architecture for XML Binding)是一种特殊的序列化/反序列化工具，可实现Java对象与XML的相互转换。
在JAXB中将一个Java对象——>XML的过程称之为Marshal，XML——>Java对象的过程称之UnMarshal。
@XmlRootElement
public class SClass
{
private String cnum;
private List<Student> students;
public SClass()
{
super();
}
public SClass(String cnum, List<Student> students)
{
super();
this.cnum = cnum;
this.students = students;
}

public String getCnum()
{
return cnum;
}
public void setCnum(String cnum)
{
this.cnum = cnum;
}
public List<Student> getStudents()
{
return students;
}
public void setStudents(List<Student> students)
{
this.students = students;
}
}
public class Student
{
private String num;
private String name;
public Student()
{
super();
}
public Student(String num, String name)
{
super();
this.num = num;
this.name = name;
}
public String getNum()
{
return num;
}
public void setNum(String num)
{
this.num = num;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
}

public class JaxbTest
{
@Test
public void test01() throws IOException
{
try
{
JAXBContext ctx = JAXBContext.newInstance(SClass.class);
Marshaller marshaller = ctx.createMarshaller();
List<Student> lstStudent = new ArrayList<Student>();
Student s1 = new Student("001", "xy");
Student s2 = new Student("002", "lw");
lstStudent.add(s1);
lstStudent.add(s2);
SClass sclass = new SClass("c001", lstStudent);

// 生成的XML文件位置
String path = "D:/sclass.xml";
File file = new File(path);
if (!file.exists())
{
file.createNewFile();
}
// 编码格式
marshaller.setProperty(Marshaller.JAXB_ENCODING, "gb2312");
// 是否格式化生成的XML
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
// 是否省略XML头信息<?xml version="1.0" encoding="gb2312" standalone="yes"?>
marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);
// 生成
marshaller.marshal(sclass, file);
}
catch (JAXBException e)
{
e.printStackTrace();
}
}

@Test
public void test02() throws Exception
{
try
{
String path = "D:/sclass.xml";
InputStream is = new FileInputStream(path);
String content = IOUtils.getString(is);
JAXBContext ctx = JAXBContext.newInstance(SClass.class);
Unmarshaller um = ctx.createUnmarshaller();
SClass sclass = (SClass) um.unmarshal(new StringReader(content));
System.out.println(sclass.getCnum());
System.out.println(sclass.getStudents().get(1).getName());
}
catch (JAXBException e)
{
e.printStackTrace();
}
}
}
test01 执行结果：对象——>XML，生成XML标签的顺序按照首字母的顺序
<sClass>
<cnum>c001</cnum>
<students>
<name>xy</name>
<num>001</num>
</students>
<students>
<name>lw</name>
<num>002</num>
</students>
</sClass>

test02执行结果：
c001
lw
关于IOUtils可以参看我的博客：http://woshixy.blog.51cto.com/5637578/1316935