好久没有更新了,偷懒,该打!  1、这个是一个基本的文件操作,实现对文件读取、写入一个数字的操作的 package trying; import java.io.*;  
/**  * @author gooing  */ public class FileRw {     private File f = new File("d:\\j2\\a.txt");     public int getNum(){         int i = -1;         try{             String stri="";             BufferedReader in = new BufferedReader(new FileReader(f));             while((stri=in.readLine())!=null){                 i = Integer.parseInt(stri.trim());             }             in.close();         }catch(Exception e){             e.printStackTrace();         }         return i;     }     public void setNum(){         int i = getNum();         i++;                 try{             PrintWriter out=new PrintWriter(new BufferedWriter(new FileWriter(f,false)));                         out.write(String.valueOf(i));              //可能是编码的原因,如果直接写入int的话,将出现java编码和windows编码的混乱,因此此处写入的是String             out.close() ;         }catch(Exception e){             e.printStackTrace();         }     }     public static void main(String[] args) {         FileRw frw = new FileRw();         for(int i =0;i<100; i++){             frw.setNum();             System.out.println(frw.getNum());         }     } }
  2、下面这个是学习工厂模式的一个例子 //Garden.java实现一个抽象花园工厂,你可以从中得到该花园的中心植物和周边植物; //当然,对于不同的花园而言,其中心植物和周边植物是不一样的 package pkgfactory; 
/**  * @author gooing TODO To change the template for this generated type  *         comment go to Window - Preferences - Java - Code Style - Code  *         Templates  */ public abstract class Garden {     public abstract Plant getCenter();     public abstract Plant getBorder(); 
    public void memo() {         System.out.println("CenterPlant:" + getCenter().getName());         System.out.println("BorderPlant:" + getBorder().getName());         System.out.println("---------------------");     } }
  //Plant.java 实现对花园中植物的基本抽象,此处只提供一个植物的name属性 package pkgfactory;  public class Plant {     public Plant(String name) {         this.name = name;     } 
    public String getName() {         return name;     } 
    private String name; }
  //VerGarden.java 和FlowerGarden.java 分别实现了一个菜园子和花园子 package pkgfactory; public class VegGarden extends Garden {     public Plant getCenter() {         return new Plant("Wheat");     } 
    public Plant getBorder() {         return new Plant("Carrot");     } }
  package pkgfactory;  public class FlowerGarden extends Garden {     public Plant getCenter() {         return new Plant("Rose");     } 
    public Plant getBorder() {         return new Plant("JuHua");     } }
  //Gardener.java是该例程的一个驱动 package pkgfactory; public class Gardener {     public static void main(String[] args) {         Garden g1 = new FlowerGarden();         Garden g2 = new VegGarden();         g1.memo();         g2.memo();     } }
 
 
   
 
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