Strategy Design pattern - Implementation [Compress files]

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Strategy Design pattern - Implementation [Compress files]

Strategy Design pattern - Implementation [Compress files] - Class Diagram

CompressionStrategy.java

import java.io.File;

import java.util.ArrayList;

public interface CompressionStrategy

{

public void compressFiles( ArrayList<File> files,String compressedArchiveFileName );

}

ZipCompressionStrategy.java

import java.io.File;

import java.util.ArrayList;

public class ZipCompressionStrategy implements CompressionStrategy

{

public void compressFiles( ArrayList<File> files, String compressedArchiveFileName )

{

System.out.println("Files are compressed using zip approach: '" + compressedArchiveFileName

               + ".zip' file is created");

}

}

RarCompressionStrategy.java

import java.io.File;

import java.util.ArrayList;

public class RarCompressionStrategy implements CompressionStrategy

{

public void compressFiles( ArrayList<File> files, String compressedArchiveFileName )

{

System.out.println("Files are compressed using Rar approach: '" + compressedArchiveFileName

               + ".rar' file is created");

}

}

CompressionContext.java

import java.io.File;

import java.util.ArrayList;

public class CompressionContext

{

private CompressionStrategy strategy;

//Client will set what CompressionStrategy to use by calling this method

public void setCompressionStrategy( CompressionStrategy strategy )

{

this.strategy = strategy;

}

public void createArchive( ArrayList<File> files,String compressedArchiveFileName )

{

strategy.compressFiles(files,compressedArchiveFileName);

}

}

Client.java

import java.io.File;

import java.util.ArrayList;

public class Client

{

public static void main( String[] args )

{

ArrayList<File> fileList = new ArrayList<File>();

fileList.add(new File("D:\\Javafiles\\Javadoc.txt"));

fileList.add(new File("D:\\Javafiles\\Release.txt"));

CompressionContext ctx = null;

ctx = new CompressionContext();

ctx.setCompressionStrategy(new ZipCompressionStrategy());

ctx.createArchive(fileList,"Javafiles");

ctx = new CompressionContext();

ctx.setCompressionStrategy(new RarCompressionStrategy());

ctx.createArchive(fileList,"Javafiles");

}

}

Output

Files are compressed using zip approach: 'Javafiles.zip' file is created

Files are compressed using Rar approach: 'Javafiles.rar' file is created

See also:

Strategy Design pattern - Introduction

Strategy Design pattern - Real Time Example [Compress files]

Strategy Design pattern - Real Time Example [Payment]

Strategy Design pattern - Real Time Example [Travel]

Strategy Design pattern - Real Time Example [Sorting]

Strategy Design pattern - Real Time Example [Search]

Strategy Design pattern - Class Diagram

Strategy Design pattern - Sequence Diagram

Strategy Design pattern - Implementation [Travel]

Strategy Design pattern - Implementation [Payment]

Strategy Design pattern - Implementation [Search]

Strategy Design pattern - Implementation [Sort]

Strategy Design pattern - KeyPoints

All Design Patterns Links