XStream集合的转换

[Asura211]

先上代码，再说问题

public class Test {

	public static void main(String[] args) {
		Student s1 = new Student();
		Student s2 = new Student();
		s1.setName("xiaoMing");
		s2.setName("xiaoHong");
		s1.setNo("001");
		s2.setNo("002");
		List<Student> list = new ArrayList<Student>();
		list.add(s1);
		list.add(s2);
		Teacher teacher = new Teacher();
		teacher.setName("WangLaoshi");
		teacher.setStudent(list);
		
		XStream xs = new XStream();
		xs.alias("student", Student.class);
		xs.alias("teacher", Teacher.class);
		xs.addImplicitCollection(Teacher.class, "students");
		//转换成XML
		String xml = xs.toXML(teacher);
		System.out.println(xml);
		//再转换成对象，students为空，输出结果报空指针异常
		Teacher t2 = (Teacher) xs.fromXML(xml);
		System.out.println(t2.getStudents().size());
	}

}

class Teacher{
	
	private String name;
	private List<Student> students;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public List<Student> getStudents() {
		return students;
	}
	public void setStudent(List<Student> students) {
		this.students = students;
	}
}

class Student{
	
	private String name;
	private String no;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getNo() {
		return no;
	}
	public void setNo(String no) {
		this.no = no;
	}
	
}

如上代码所示，我利用addImplicitCollection(Teacher.class, "students")将<students>标签给去掉了，xml输出结果为

<teacher>
  <name>WangLaoshi</name>
  <student>
    <name>xiaoMing</name>
    <no>001</no>
  </student>
  <student>
    <name>xiaoHong</name>
    <no>002</no>
  </student>
</teacher>

但是当我想要将此xml再转换成java对象时，却发现得到的Teacher对象中的students为空，转换失败了，请问这是为何？

[Asura211]

没人回答么？困扰我两天了。。。