用于读取不同文件格式的策略模式

public interface FileReader {

  void readFile();
   void writeFile();
}


 public class XMLReader implements FileReader {

  @Override
   public void readFile() {
    System.out.println("Hellp i am read");

   }

   @Override
   public void writeFile() {
        System.out.println("Hello i am write");
    }


 }

  public class ExcelReader implements FileReader {

  @Override
   public void readFile() {
    System.out.println("Hellp i am read");

   }

   @Override
   public void writeFile() {
        System.out.println("Hello i am write");
    }

}

public class Context {

   FileReader reader ;

   public Context(FileReader reader) {
    super();
    this.reader = reader;
   }

   public void executeRead(){

        reader.readFile();
    }


       }

public class TestStrategy {

public static void main(String[] args) {
    // TODO Auto-generated method stub

    System.out.println(args[0]);
    String s=args[0];
    String[] a=s.split("\.");
    if(a[1].equals("csv")){
        new Context(new XMLReader()).executeRead();
    }else{
        new Context(new ExcelReader()).executeRead();
    }
}

}
public interface FileReader {

  void readFile(