Java学习笔记 线程，注解(注释)...

笔记

Annotation

// 创建config.properties文件// 文件中存放的内容person=com.linj.thread.Student// 自定义注解import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;@Retention(RetentionPolicy.RUNTIME)// 注释的范围@Target(ElementType.FIELD) // 注释的类型public @interface StudentAnnotation {    int value(); // 注释一个int值}// 注解工厂import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.IOException;import java.util.Properties;public class Factory {    public static Person creatPerson() {        Person person = null;        Properties p = new Properties();        try {            p.load(new FileInputStream("config.properties"));            String clazzName = p.getProperty("person");            Class clazz = Class.forName(clazzName);            person = (Person) clazz.newInstance();        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        } catch (ClassNotFoundException e) {            e.printStackTrace();        } catch (InstantiationException e) {            e.printStackTrace();        } catch (IllegalAccessException e) {            e.printStackTrace();        }        return person;    }}// 在一个类中import java.lang.reflect.Field;public class Student extends Person{    @StudentAnnotation(18)    private int age;    private String name;    public String clazz;    public Student() {        // 得到student类的Class的对象，this指test中的Student对象zhangsan        Class clazz = this.getClass();        try {            Field field = clazz.getDeclaredField("age");            StudentAnnotation sa = field.getAnnotation(StudentAnnotation.class);            // 得到age属性的StudentAnnotation注解，如果没有返回null            if(sa != null) {                int i = sa.value();                field.setAccessible(true);                field.set(this, i);                field.setAccessible(false);            }        } catch (NoSuchFieldException e) {            e.printStackTrace();        } catch (SecurityException e) {            e.printStackTrace();        } catch (IllegalArgumentException e) {            e.printStackTrace();        } catch (IllegalAccessException e) {            e.printStackTrace();        }    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getClazz() {        return clazz;    }    public void setClazz(String clazz) {        this.clazz = clazz;    }    public int getAge() {        return age;    }    @Override    public void sleep() {        System.out.println("困");    }}

多线程

// 火车票售票，线程同步，安全问题public class TestThread implements Runnable{    int count = 120;    public synchronized void doIt() {        if(count > 0) {            try {                Thread.sleep(100);            } catch (Exception e) {                e.printStackTrace();            }            System.out.println(Thread.currentThread().getName() + "车票剩余" + --count);        }    }    @Override    public void run() {        while (true) {            doIt();        }    }    public static void main(String[] args) {        TestThread t = new TestThread();        Thread tA = new Thread(t,"1");        Thread tB = new Thread(t,"2");        Thread tC = new Thread(t,"3");        Thread tD = new Thread(t,"4");        Thread tE = new Thread(t,"5");        Thread tF = new Thread(t,"6");        tA.start();        try {            tB.join();            tB.start();        } catch (InterruptedException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }//      tB.start();//      tC.start();//      tD.start();//      tE.start();//      tF.start();    }}// 两个线程锁死的情况public class MyRunnable1 implements Runnable{    String lock1 = "a";    String lock2 = "b";    @Override    public void run() {        synchronized (lock1) {            try {                Thread.sleep(1000);            } catch (InterruptedException e) {                e.printStackTrace();            }            System.out.println("等lock2");            synchronized (lock2) {                System.out.println("我要走了");            }        }    }public class MyRunnable2 implements Runnable{    String lock1 = "a";    String lock2 = "b";    @Override    public void run() {        synchronized (lock2) {            try {                Thread.sleep(1000);            } catch (InterruptedException e) {                e.printStackTrace();            }            System.out.println("等lock1");            synchronized (lock1) {                System.out.println("我要走了");            }        }    }}// 测试类部分代码MyRunnable1 r1= new MyRunnable1();        MyRunnable2 r2= new MyRunnable2();        Thread t1 = new Thread(r1);        Thread t2 = new Thread(r2);        t1.start();        t2.start();// 银行取款public class BankTest implements Runnable{    int money = 1000;    public synchronized void getMoney() {            if(money >= 100) {                try {                    Thread.sleep(50);                    System.out.println(Thread.currentThread().getName() +                            "取款100 \n余额:" + (money -= 100));                } catch (InterruptedException e) {                    e.printStackTrace();                }            }    }    @Override    public void run() {        while(true) {            getMoney();        }    }    public static void main(String[] args) {        BankTest t = new BankTest();        Thread a = new Thread(t,"a");        Thread b = new Thread(t,"b");        a.start();        b.start();    }}

总结

来日再见当初的浅薄，学习需要认真和积累