public class HelloWorld {
    /* 第一个Java程序
     * 它将打印字符串 Hello World
     */
    public static void main(String []args) {
        System.out.println("Hello World"); // 打印 Hello World
    }
}

// byte  
System.out.println("基本类型：byte 二进制位数：" + Byte.SIZE);  
System.out.println("包装类：java.lang.Byte");  
System.out.println("最小值：Byte.MIN_VALUE=" + Byte.MIN_VALUE);  
System.out.println("最大值：Byte.MAX_VALUE=" + Byte.MAX_VALUE);  

// 包装类
public class Wrapper {
    public static void main(String[] args) {
        // 装箱：将基本类型转换成包装类
        int a = 1;
        Integer v1 = new Integer(a);    // 手动装箱
        Integer v2 = a;                 // 自动装箱

        // 拆箱：将包装类型转成基本类型
        int b = v1.intValue();      // 手动拆箱
        int c = v2;                 // 自动拆箱

        // 包装类用法一：本类型与其他类型转换
        Integer v3 = 3;
        System.out.println("v3-->" + v3);
        float f1 = v3.floatValue();
        System.out.println("f1-->" + f1);
        byte b1 = v3.byteValue();
        System.out.println("b1-->" + b1);
        String str1 = v3.toString();
        System.out.println("str1-->" + str1);
        System.out.println();

        // 包装类用法二：字符串和本类型以及基本类型之间的转换
        String str2 = "122";
        int i1 = Integer.parseInt(str1);
        System.out.println("i1-->" + i1);
        float f2 = Float.parseFloat(str2);
        System.out.println("f2-->" + f2);
        float f3 = 3.1f;
        String str_f2 = String.valueOf(f3);
        System.out.println("str_f2-->" + str_f2);
        
    }
}

public class EqualCompare {
    public static void main(String[] args) {
        // 基本数据类型
        int a1 = 1;
        Integer a2 = 1;
        int b1 = 1;
        Integer b2 = 1;

        System.out.println(a1 == b1);
        System.out.println(a2.equals(b2));
        System.out.println();

        String s1 = "123";  // 存放在常量池
        String s11 = "123";
        String s2 = new String("123");  // 存放在堆中
        System.out.println(s1 == s11);
        System.out.println(s1 == s2);
        System.out.println(s1.equals(s2));
    }
}

public class Main {
    public static void main(String[] args) {
        try {
            double num = 1 / 0;
        } catch (ArithmeticException e) {
            System.out.println(e.getMessage());
            e.printStackTrace();
        }
        System.out.println("这里被执行了");
    }
}

public class Main {
    private static double max(double a, double b) {
        return a > b ? a : b;
    }

    private static <T extends Comparable> T max_T(T a, T b) {
        // 等于返回0，大于返回1，小于返回-1
        if (a.compareTo(b) > 0)
            return a;
        else
            return b;
    }

    public static void main(String[] args) {
        Integer i1 = 1;
        Integer i2 = 2;
        Integer i3 = max_T(i1, i2);
        System.out.println(i3);
    }
}

package code5_2;

public class Shape<T> {
    private T temp;

    Shape() {

    }

    Shape(T temp) {
        this.temp = temp;
    }

    public void setTemp(T temp) {
        this.temp = temp;
    }

    public T getTemp() {
        return this.temp;
    }

}

public class GenericTest {
     
    public static void main(String[] args) {
        List<String> name = new ArrayList<String>();
        List<Integer> age = new ArrayList<Integer>();
        List<Number> number = new ArrayList<Number>();
        
        name.add("icon");
        age.add(18);
        number.add(314);
 
        //getUperNumber(name);//1
        getUperNumber(age);//2
        getUperNumber(number);//3
       
   }
 
   public static void getData(List<?> data) {
      System.out.println("data :" + data.get(0));
   }
   
   public static void getUperNumber(List<? extends Number> data) {
          System.out.println("data :" + data.get(0));
       }

public class MyThread extends Thread {
    @Override
    public void run() {
        System.out.println("Thread 被执行");
    }
}

public class MyRunnable implements Runnable {
    @Override
    public void run() {
        System.out.println("runnable thread 被执行");
    }
}

public class Main {
    public static void main(String[] args) {
        MyThread myThread = new MyThread();
        myThread.run();
        Thread thread = new Thread(new MyRunnable());
        thread.run();
    }
}

public synchronized void save(){}

synchronized(object){}

public class Producer implements Runnable {
    private int contents;
    private boolean available = false;
    private Thread producer;
    private Thread consumer;

    public synchronized int get() {
        while (available == false) {
            try {
                wait(); //释放锁，等候producer放值
            } catch (InterruptedException e) {
            }
        }
        available = false;
        System.out.println("Consumer gets:" + contents);
        notifyAll();
        return contents;
    }

    public synchronized void put(int value) {
        while (available == true) {
            try {
                wait(); //释放锁，等候consumer取值
            } catch (InterruptedException e) {
            }
        }
        contents = value;
        available = true;
        System.out.println("Producer produces:" + contents);
        notifyAll();
    }

    @Override
    public void run() {
        if (Thread.currentThread() == producer) {
            for (int i = 0; i <= 9; i++) put(i);
        } else {
            for (int i = 0; i <= 9; i++) get();
        }
    }

    Producer(){
        producer = new Thread(this);
        consumer = new Thread(this);
        producer.start();
        consumer.start();
    }

    public static void main(String[] args) {
        new Producer();
    }
}

public class Main {
    public static void main(String[] args) {
        File file = new File("C:\\Users\\Administrator\\Desktop\\JavaTrain\\mangzhong.mp3");
        if(!file.isDirectory())
            file = new File(file.getParent());
        File[] listFiles = file.listFiles();
        System.out.println(listFiles.length);
        for (File f:listFiles) {
            System.out.println(f.getName());
        }
    }
}

public class Main {
    public static void main(String[] args) throws IOException {
        File file = new File("C:\\Users\\Administrator\\Desktop\\JavaTrain\\cont.txt");
        File out = new File("C:\\Users\\Administrator\\Desktop\\JavaTrain\\img\\cont.txt");
        FileInputStream inputStream = new FileInputStream(file);
        FileOutputStream outputStream = new FileOutputStream(out);

        int size = inputStream.available();
        for (int i = 0; i < size; i++) {
            byte temp = (byte) inputStream.read();
            outputStream.write(temp);
            System.out.println((char) temp);
        }
        inputStream.close();
        outputStream.close();
    }
}

public class Main {
    public static void main(String[] args) throws IOException {
        File file = new File("C:\\Users\\Administrator\\Desktop\\JavaTrain\\cont.txt");
        File out = new File("C:\\Users\\Administrator\\Desktop\\JavaTrain\\img\\cont.txt");
        FileInputStream inputStream = new FileInputStream(file);
        FileOutputStream outputStream = new FileOutputStream(out);
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "UTF-8");
        OutputStreamWriter outputStreamWriter =  new OutputStreamWriter(outputStream, "UTF-8");
        while (inputStreamReader.ready()){
            char temp = (char)inputStreamReader.read();
            outputStreamWriter.write(temp);
            System.out.println(temp);
        }
        outputStreamWriter.append("123456");
        inputStreamReader.close();  // 注意顺序

        inputStream.close();
        outputStreamWriter.close();
        outputStream.close();
    }
}

public class GET {
    public String send(String url, String param) throws FileNotFoundException {
        String result = "";
        BufferedReader in = null;
        File out = new File("C:\\Users\\Administrator\\Desktop\\JavaTrain\\img\\cont.mp3");
        FileOutputStream outputStream = new FileOutputStream(out);

        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            // 设置通用的请求属性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立实际的连接
            connection.connect();
            // 获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍历所有的响应头字段
            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }
            // 定义 BufferedReader输入流来读取URL的响应
            InputStream inputStream = connection.getInputStream();
            int size = inputStream.available();
            for (int i = 0; i < size; i++) {
                outputStream.write(inputStream.read());
            }
            outputStream.close();
            inputStream.close();
            
//            in = new BufferedReader(new InputStreamReader(
//                    connection.getInputStream()));
//            String line;
//            while ((line = in.readLine()) != null) {
//                result += line;
//            }
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }
}

public class PlayLocalMP3 {
    public static void main(String[] args) throws FileNotFoundException, JavaLayerException {
        File file = new File("C:\\Users\\Administrator\\Desktop\\JavaTrain\\mangzhong.mp3");
        FileInputStream fileInputStream= new FileInputStream(file);
        Player player = new Player(fileInputStream);
        player.play();
    }
}