클래스에 Java 동기화 블록 사용

class Block {
  // synchronized block starts from here
  void printBlock(int b) {
    synchronized (this) {
      System.out.println("The block output is: ");
      for (int j = 1; j <= 4; j++) {
        System.out.println(b * j);

        // handles exception
        try {
          Thread.sleep(500);
        } catch (Exception e) {
          System.out.println(e);
        }
      }
    }
  } // ending
}

class S1 extends Thread {
  Block s;
  S1(Block s) {
    this.s = s;
  }

  public void run() {
    s.printBlock(10);
  }
}

class S2 extends Thread {
  Block s;
  S2(Block s) {
    this.s = s;
  }

  public void run() {
    s.printBlock(200);
  }
}

class SyncBlock {
  // main method
  public static void main(String args[]) {
    // object creation
    Block obj = new Block();
    S1 s1 = new S1(obj);
    S2 s2 = new S2(obj);

    // run the threads s1 and s2
    s1.run();
    s2.run();
  }
}

The block output is:
10
20
30
40
The block output is:
200
400
600
800

import java.util.*;

class synchronize {
  String title = "";
  public int c = 0;
  public void result(String s, List<String> li) {
    // only one thread is allowed to change the title simultaneously.
    synchronized (this) {
      title = s;
      c++;
    }

    li.add(s);
  }
}

class SyncBlock {
  // main method
  public static void main(String[] args) {
    // for synchronize class, we have created an object
    synchronize ob = new synchronize();

    // we have created a list here
    List<String> li = new ArrayList<String>();

    // for calling the method, a string is passed to it
    ob.result("Sprint Planning", li);
    System.out.println(ob.title);
  }
}

Sprint Planning