Map的三种遍历方法！！

转载自：http://www.cnblogs.com/christ/archive/2010/10/30/1865134.html

?

map的三种遍历方法！

class Student {

private String name;
private String id;
private int age;

public Student(String name, String id, int age) {
this.name = name;
this.id = id;
this.age = age;
}

@Override
public String toString() {
return "Student{" + "name=" + name + "id=" + id + "age=" + age + '}';
}
}