Java多线程

import java.io.IOException;
import java.util.Set;

public class ProcessBuilderDemo
{

    public static void main(String[] args)
    { 
        final Person p=new Person();

        Thread thread=new Thread()
        {
            boolean flag=false;
            public void run()
            {
                
                while (true)
                {
                    if (flag==false)
                    {
                        p.name="张三";
                        p.sex="女";
                        flag=true;
                    }
                    else 
                    {
                        p.name="李四";
                        p.sex="男";
                        flag=false;
                    }
                }
                
            }
        };
        Runnable runnable=new Runnable()
        {
            public void run()
            {
                while (true)
                {
                    System.out.println(p.name+""+p.sex);
                }
            }
        };
        
        thread.start();
        new Thread(runnable).start();
        
    }
    
}
 class Person
{
      String name="1";
        String sex="1";
}

以上代码线程不是安全的，所以会出现交替打印

public class ProcessBuilderDemo
{

    public static void main(String[] args)
    {
        final Person p = new Person();

        Thread thread = new Thread()
        {
            boolean flag = false;

            public void run()
            {

                while (true)
                {
                    if (flag == false)
                    {
                        
                            p.SetNameAndSex("张三","男");
                            flag = true;
                        
                    }
                    else
                    {
                        
                            p.SetNameAndSex("李四","女");
                            flag = false;
                        
                    }
                }

            }
        };
        Runnable runnable = new Runnable()
        {
            public void run()
            {
                while (true)
                {
                    p.GetNameAndSex();
                }
            }
        };

        thread.start();
        new Thread(runnable).start();

    }

}

class Person
{
    String name = "1";
    String sex = "1";
    public  void setName(String name)
    {
        this.name=name;
    }
    public String getName()
    {
        return this.name;
    }
    
    public  void setSex(String sex)
    {
        this.sex=sex;
    }
    public String getSex()
    {
        return this.sex;
    }
    public synchronized void SetNameAndSex(String name,String sex)
    {
        this.name=name;
        this.sex=sex;
    }
    public synchronized void GetNameAndSex()
    {
        System.out.println(this.name+"---"+this.sex);
    }
}