深入理解Java中的内存泄漏内存泄漏内存泄漏发生的原因造成内存泄露的常见情形内存泄露的解决方案

Static Vector v = new Vector(10);
for (int i = 1; i<100; i++)
{
Object o = new Object();
v.add(o);
o = null;
}

package 校招;

import java.util.HashSet;
import java.util.Set;

public class MemoryOut {
    public static void main(String[] args) {
        Set<Person> set = new HashSet<Person>();
        Person p1 = new Person("唐僧","pwd1",25);
        Person p2 = new Person("孙悟空","pwd2",26);
        Person p3 = new Person("猪八戒","pwd3",27);
        set.add(p1);
        set.add(p2);
        set.add(p3);
        System.out.println("总共有:"+set.size()+" 个元素!"); //结果：总共有:3 个元素!
        p3.setAge(2); //修改p3的年龄,此时p3元素对应的hashcode值发生改变
        set.remove(p3); //此时remove不掉，造成内存泄漏
        set.add(p3); //重新添加，居然添加成功
        System.out.println("总共有:"+set.size()+" 个元素!"); //结果：总共有:4 个元素!
        for (Person person : set)
        {
        System.out.println(person);
        }
    }
}

class Person {
    
    int age;
    String name;
    String password;
    
    public Person(String name, String password, int age) {
        this.name = name;
        this.password = password;
        this.age = age;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + age;
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Person other = (Person) obj;
        if (age != other.age)
            return false;
        return true;
    }
    
}

class A{
public A(){
B.getInstance().setA(this);
}
....
}
//B类采用单例模式
class B{
private A a;
private static B instance=new B();
public B(){}
public static B getInstance(){
return instance;
}
public void setA(A a){
this.a=a;
}
//getter...
}