An AutoCloseable Resource Class - Java Language Basics

Java examples for Language Basics:AutoCloseable

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Description

An AutoCloseable Resource Class

Demo Code

public class Main {
  public static void main(String[] args) {
    // Its close() method will be called automatically */
    try (MyResource mr = new MyResource(2, false)) {
      mr.use();/*  ww  w  .  j  av  a 2 s.  co  m*/
      mr.use();
    }
    try (MyResource mr = new MyResource(2, true)) {
      mr.use();
      mr.use();
    }
  }
}


class MyResource implements AutoCloseable {
    private int score;
    private boolean errorOut;

    public MyResource(int level, boolean exceptionOnClose) {
        this.score = level;
        this.errorOut = exceptionOnClose;
        System.out.println("Creating MyResource. Level = " + level);
    }

    public void use() {
        if (score <= 0) {
            throw new RuntimeException("Low in level.");
        }
        System.out.println("Using MyResource level " + this.score);
        score--;
    }

    @Override
    public void close() {
        if (errorOut) {
            throw new RuntimeException("Error in closing");
        }
        System.out.println("Closing MyResource...");
    }
}

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