java-design-patterns/execute-around/src/main/java/com/iluwatar/execute/around/App.java

package com.iluwatar.execute.around;

import java.io.FileWriter;
import java.io.IOException;

/**
 * The Execute Around idiom specifies some code to be executed before and after a method. Typically
 * the idiom is used when the API has methods to be executed in pairs, such as resource
 * allocation/deallocation or lock acquisition/release.
 * <p>
 * In this example, we have {@link SimpleFileWriter} class that opens and closes the file for the
 * user. The user specifies only what to do with the file by providing the {@link FileWriterAction}
 * implementation.
 *
 */
public class App {

  /**
   * Program entry point
   * 
   * @param args command line args
   * @throws IOException
   */
  public static void main(String[] args) throws IOException {

    new SimpleFileWriter("testfile.txt", new FileWriterAction() {

      @Override
      public void writeFile(FileWriter writer) throws IOException {
        writer.write("Hello");
        writer.append(" ");
        writer.append("there!");
      }
    });
  }
}