如何保存文件和阅读 [英] How to save file and read

问题描述

我创建了一个将网格布局格式的随机图像放置的程序。
网格布局的大小是6 x 6 = 36.
只有10个图像被填满（每个图像都不同），其余都是空的。

alt text http://freeimagehosting.net/uploads/bfb7e85f63.jpg

如何将其保存到文件并再次读取，以便在网格上显示相同图像的相同图像？

以下是我用来保存图像的代码：

  //图像文件
 String [] arrPic = {pic1.jpg，pic2.jpg，pic3.jpg，pic4.jpg，pic5.jpg，pic6.jpg，pic7.jpg，pic8 .JPG， pic9.jpg， pic10.jpg ,, pic11.jpg， pic12.jpg， pic13.jpg}; 
 
 ArrayList< String> pictures = new ArrayList< String>（Arrays.asList（arrPic））; 
 
 ArrayList< String> file = new ArrayList< String>（）; 
 
 JPanel pDraw = new JPanel（new GridLayout（6,6,2,2））; 
 ... 
 
 //用空标签填充所有网格
 for（int i = 0; i <（6 * 6）; i ++）{
 JLabel lbl = new JLabel（）; 
 pDraw.add（lbl）; 
} 
 ... 
 
 //选择随机框以填充图像
（int i = 0; i <10; i ++）{
布尔数=真; 
 while（number）{
 int n = rand.nextInt（35）; 
 if（！（arraylist.contains（n）））
 number = false; 
 arraylist.add（n）; 
} 
 
 //用图像填充网格
 for（int i = 0; i< arraylist.size（）; i ++）{
 
 //从arraylist 
中选择随机图像int index = rand.nextInt（pictures.size（））; 
 String fileName =（String）pictures.get（index）; 
 
 //找到图片文件
 icon = createImageIcon（fileName）; 
 
 //将文件保存到新文件中
 file.add（fileName）; 
 
 //重新缩放图片
 int x = rand.nextInt（50）+50; 
 int y = rand.nextInt（50）+50; 
 
 Image image = icon.getImage（）。getScaledInstance（x，y，Image.SCALE_SMOOTH）; 
 icon.setImage（image）; 
 
 //删除空标签并将其替换为图像
 int one =（Integer）arraylistist.get（i）; 
 pDraw.remove（one）; 
 final JLabel标签; 
 pDraw.add（label，one）; 
 
 
 
 
解决方案
在你的代码，是类 java.util.Random 的 rand ？如果是这样，你可以自己种下，然后将种子值保存到文本文件中。对于任何给定的种子，（伪）随机数发生器将以相同的顺序产生相同的随机数字。所以：
 
 
 随机rand = null; 
  
然后，创建一个新的种子并将其保存到文件中：
  long seed = System.currentTimeMillis（）; 
 rand = new Random（seed）; 
尝试{
 BufferedWriter writer = new BufferedWriter（new FileWriter（whatever.txt））; 
 writer.write（Long.toString（seed））; 
 writer.close（）; 
} catch（IOException e）{
 e.printStackTrace（）; 
} 
  
或者将以前保存的值读回： 
 
 
  long seed = 0; 
尝试{
 BufferedReader reader = new BufferedReader（new FileReader（whatever.txt））; 
 seed = Long.parseLong（reader.readLine（））; 
 reader.close（）; 
} catch（IOException e）{
 e.printStackTrace（）; 
} 
 rand = new Random（seed）; 
  
请注意，此代码不会检查以确保文件退出，或文件isn不是空的，或者文件不包含有效数字以外的内容等。
 
I create a program that place random image in grid layout format.
The size of the grid layout is 6 x 6 = 36.
Only 10 were filled with images (each image was different) and the rest were empty.

alt text http://freeimagehosting.net/uploads/bfb7e85f63.jpg

How can I save it to a file and read it again, so it will display the same images with same placement on the grid?

Here is the code that I used to save the images:
//image file
String []arrPic = {"pic1.jpg","pic2.jpg","pic3.jpg","pic4.jpg","pic5.jpg","pic6.jpg","pic7.jpg","pic8.jpg","pic9.jpg","pic10.jpg",,"pic11.jpg","pic12.jpg","pic13.jpg"};

ArrayList<String> pictures = new ArrayList<String>(Arrays.asList(arrPic));

ArrayList<String> file = new ArrayList<String>();    

JPanel pDraw = new JPanel(new GridLayout(6,6,2,2));
...

//fill all grids with empty label
for (int i =0; i<(6*6); i++){   
   JLabel lbl = new JLabel("");
   pDraw.add(lbl);  
}
...

//Choose random box to be filled with images
for(int i=0; i<10; i++){ 
   Boolean number = true;
   while(number){
   int n = rand.nextInt(35); 
   if(!(arraylist.contains(n)))
     number = false;
   arraylist.add(n);
}

//fill the grids with images
for(int i=0; i<arraylist.size(); i++){

   //select random image from arraylist
   int index = rand.nextInt (pictures.size());
   String fileName = (String) pictures.get(index );

   //find the image file
   icon = createImageIcon(fileName);   

   //save the file in a new file
   file.add(fileName);

   //rescaled the image      
   int x = rand.nextInt(50)+50;
   int y = rand.nextInt(50)+50;

   Image image = icon.getImage().getScaledInstance(x,y,Image.SCALE_SMOOTH);         
   icon.setImage(image);

   //remove empty label and replace it with an image
   int one = (Integer) arraylist.get(i);
   pDraw.remove(one);                           
   final JLabel label;
   pDraw.add(label,one); 

}

解决方案
In your code, is rand of the class java.util.Random? If so, you could "seed" it yourself, and then just save the seed value to a text file. For any given seed, a (pseudo-)random number generator will produce the same "random" numbers in the same order. So:
Random rand = null;
Then, either create a new "seed" and save it to a file:
long seed = System.currentTimeMillis();
rand = new Random(seed);
try {
    BufferedWriter writer = new BufferedWriter(new FileWriter("whatever.txt"));
    writer.write(Long.toString(seed));
    writer.close();
} catch(IOException e) {
    e.printStackTrace();
}
Or read a previously saved value back in:
long seed = 0;
try {
    BufferedReader reader = new BufferedReader(new FileReader("whatever.txt"));
    seed = Long.parseLong(reader.readLine());
    reader.close();
} catch(IOException e) {
    e.printStackTrace();
}
rand = new Random(seed);
Do note that this code doesn't check to make sure the file exits, or that the file isn't empty, or that the file doesn't contain something other than a valid number, etc...

                        
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