[Java] 纯文本查看 复制代码
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
//HashMap存储键是自定义对象值是String
//每位学生（姓名，年龄）都有自己的家庭住址。那么，既然有对应关系，则将学生对象和家庭住址存储到map集合中。
//学生作为键, 家庭住址作为值, 并使用keySet和entrySet方式遍历Map集合.
//注意，学生姓名相同并且年龄相同视为同一名学生
public class Test07 {
public static void main(String[] args) {
HashMap<Student, String> map = new HashMap<Student, String>();
map.put(new Student("张三", 18), "北京");
map.put(new Student("李四", 20), "上海");
map.put(new Student("李四", 20), "大连");
map.put(new Student("赵六", 19), "深圳");
for (Student key : map.keySet()) {
System.out.println(key.toString() + "=" + map.get(key));
}
System.out.println("=================");
for(Map.Entry<Student, String> entry : map.entrySet()) {
System.out.println(entry.getKey().toString()+"="+entry.getValue());
}
}
}
public class Student {
private String name;
private int age;
public Student() {
super();
}
public Student(String name, int age) {
super();
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String toString() {
return ("["+name+" , "+age+"]");
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + age;
result = prime * result + ((name == null) ? 0 : name.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Student other = (Student) obj;
if (age != other.age)
return false;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
return true;
}
}