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

package com.iluwatar.executearound;

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.
 *
 * In this example, we have SimpleFileWriter class that opens and closes the file
 * for the user. The user specifies only what to do with the file by providing the
 * FileWriterAction implementation.
 *
 */
public class App {
	
    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!");
			}
    	});
    }
}