15/8/4反射，注解，工程设计模式，线程

反射注解

工厂设计模式

线程

反射例子

1.把所有的java文件抽象起来抽象到一个类中的方法就是反射

    public static void main(String[] args) {//把所有的java文件抽象起来抽象到一个类中的方法就是反射        Class<Student> clazz=Student.class;//      Field[] field=clazz.getFields();//返回一个包含某些 Field 对象的数组，这些对象反映此 Class 对象所表示的类或接口的所有可访问公共字段//      Field[] fields=clazz.getDeclaredFields();//以数组形式返回所有属性//      for (Field field : fields) {//          System.out.println(field.getName());//返回属性的名称//          System.out.println(field.getModifiers());//返回修饰符的整数表示形式//          System.out.println(field.getType().getName());//返回属性的类型名称//      }        Student zhangsan=new Student();//创建一个Student类对象zhangsan        try {            Field age=clazz.getDeclaredField("age");//得到指定名称的属性；            age.setAccessible(true);//取消JAVA访问修饰符的检查            age.set(zhangsan,18);//将对象张三的age属性的值更改为18            age.setAccessible(false);//取消  取消检查            System.out.println(zhangsan.getAge());//输出Student类对象zhangsan的age值        } catch (NoSuchFieldException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (SecurityException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IllegalArgumentException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IllegalAccessException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }

注解例子

@Target(ElementType.FIELD)//表示此注解只能用到属性上@Retention(RetentionPolicy.RUNTIME)//表示此注解的范围是可执行的public @interface TeacherAnnotation {    int age() default 19;//如果注解中没有给出age的值，那么默认的值为19    String name();}    @TeacherAnnotation(age=18,name="java")    private  Teacher javaTeacher;    @TeacherAnnotation(age=22,name="english")    private  Teacher englishTeacher;    @TeacherAnnotation(name="math")    private  Teacher mathTeacher;    public Clazz(){        Class clazz=Clazz.class;//创建一个Class类的对象clazz        Field[] fields=clazz.getDeclaredFields();//得到这个类中的所有属性        for (Field field : fields) {//          得到TeacherAnnotation的注解如果没有就返回Null            TeacherAnnotation ta=field.getDeclaredAnnotation(TeacherAnnotation.class);            if (ta==null) {                continue;//跳出            }else {                int age=ta.age();//得到该注解的age值，如果没有就用默认值代替                String name=ta.name();//得到该注解的name值                Teacher teacher=new Teacher();//创建一个新的Teacher对象                teacher.setAge(age);//将得到的age和name值放到该对象中                teacher.setName(name);                try {                    field.setAccessible(true);//取消java修饰符访问                    field.set(this, teacher);//将该Teacher对象放到此班级的对象中                    field.setAccessible(false);//取消 取消访问                } catch (IllegalArgumentException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                } catch (IllegalAccessException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        }    }    public Teacher getJavaTeacher() {        return javaTeacher;    }    public void setJavaTeacher(Teacher javaTeacher) {        this.javaTeacher = javaTeacher;    }    public Teacher getEnglishTeacher() {        return englishTeacher;    }    public void setEnglishTeacher(Teacher englishTeacher) {        this.englishTeacher = englishTeacher;    }    public Teacher getMathTeacher() {        return mathTeacher;    }    public void setMathTeacher(Teacher mathTeacher) {        this.mathTeacher = mathTeacher;    }    public static void main(String[] args) {        Clazz clazz=new Clazz();        System.out.println(clazz.getEnglishTeacher().getName());        System.out.println(clazz.getMathTeacher().getAge());    }

工厂化设计模式例子

    public static Person creatPerson(){//静态方法        Person person=null;        Properties p=new Properties();//创建一个无默认值的空属性列表        try {            p.load(new FileInputStream("config.properties"));//从输入流中读取属性列表（键和元素对）。            String clazzName=p.getProperty("person");//用指定的键在此属性列表中搜索属性,返回属性列表中具有指定键值得值            Class clazz=Class.forName(clazzName);//返回与带有给定字符串名的类或接口相关联的 Class 对象            person=(Person) clazz.newInstance();//创建此 Class 对象所表示的类的一个新实例        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (ClassNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (InstantiationException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IllegalAccessException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        return person;    }    public static void main(String[] args) {        Person person=Factory.creatPerson();        person.sleep();    }public class Teacher extends Person{    private int age;    private String name;    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    @Override    public void sleep() {        System.out.println("老师睡觉");    }}

线程例子

    public static void main(String[] args) {//      多个线程同时启动，同时运行相同数据//      MyThread thread1=new MyThread("西西");//      MyThread thread2=new MyThread("问问");//      MyThread thread3=new MyThread("恩恩");//      MyThread thread4=new MyThread("肉肉");//      thread1.start();//      thread2.start();//      thread3.start();//      thread4.start();//      多个线程共用一个数据//      MyRunnable runnable=new MyRunnable();//      Thread t1=new Thread(runnable,"售票员one");//      Thread t2=new Thread(runnable,"售票员two");//      Thread t3=new Thread(runnable,"售票员three");//      Thread t4=new Thread(runnable,"售票员four");//      t1.start();//      t2.start();//      t3.start();//      t4.start();//      join用法//      MyRunnable runnable=new MyRunnable();//      Thread t1=new Thread(runnable,"售票员one");//      t1.start();//      try {//          t1.join(1000);//直接调用join()指等待该线程结束 调用join(1000)指等待该线程执行1s//      } catch (InterruptedException e) {//          // TODO Auto-generated catch block//          e.printStackTrace();//      }//      System.out.println("程序运行结束");        MyCount runnable=new MyCount();        Thread t1=new Thread(runnable,"售票员one");        Thread t2=new Thread(runnable,"售票员two");        Thread t3=new Thread(runnable,"售票员three");        Thread t4=new Thread(runnable,"售票员four");        t1.start();        t2.start();        t3.start();        t4.start();    }public class MyThread extends Thread{    public MyThread(){    }    public MyThread(String name){        super(name);    }    private int tickets=100;    @Override    public void run() {        while(tickets>0){            System.out.println(getName()+"售出了第"+tickets+"张票");            tickets--;            try {                Thread.sleep(1000);            } catch (InterruptedException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }    }}public class MyRunnable implements Runnable{    private int i=100;    private String s="new";    @Override    public void run() {        while(i>0){            try {                Thread.sleep(50);            } catch (InterruptedException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }            synchronized (s) {                if (i>0) {                    System.out.println(Thread.currentThread().getName()+"卖出了第"+i+"票");                    i--;                    }            }        }    }}public class MyCount implements Runnable{    private int count=1234;     String s="money";    @Override    public void run() {        while(count>100){            try {                Thread.sleep(500);            } catch (InterruptedException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }            synchronized (s) {                if (count>100) {                    count-=100;                    System.out.println(Thread.currentThread().getName()+"取走了100还剩下"+count);                }            }        }    }}

public class MyRunnable01 implements Runnable {    @Override    public void run() {        String lock1 = "abc";        String lock2 = "123";        synchronized (lock1) {            try {                Thread.sleep(1000);            } catch (InterruptedException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }        System.out.println("我在等lock2");        synchronized (lock2) {        }    }}public class MyRunnable02 implements Runnable{    @Override    public void run() {        String lock1 = "abc";        String lock2 = "123";        synchronized (lock2) {            try {                Thread.sleep(1000);            } catch (InterruptedException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }        System.out.println("我在等lock1");        synchronized (lock1) {        }    }}public class MyRunnableLockTest {    public static void main(String[] args) {        MyRunnable01 mr1=new MyRunnable01();        MyRunnable02 mr2=new MyRunnable02();        Thread t1=new Thread(mr1,"张三" );        Thread t2=new Thread(mr2,"李四" );        t1.start();        t2.start();    }}