无法在jar中读取图像 [英] Cannot read image in jar

问题描述

我已经编写了一个程序来加密Netbeans中的图像。该程序从netbeans运行时工作正常，但是当我将其构建成.jar文件时，它不起作用，即使我将图像文件放在与.jar文件相同的文件夹中也无法读取图像。

i have written a program to encrypt an image in Netbeans. The program works fine when running from netbeans but when i build it into a .jar file its not working, it cannot read the image even though i placed the image file in the same folder as the .jar file.

    package test;

    import java.io.IOException;
    import java.io.File;
    /**
     *
 * @author AMaR
*/
public class Test {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) throws IOException, Exception {


    File EnImage = new File("encrypted.png");
    File DeImage = new File("decrypted.png");
    int[] pixels;

    LoadImage l = new LoadImage();
    l.load();
    pixels= l.getImagePixels();

    RC4New rc4 = new RC4New();
    int key[]= {13,2,4,6,};
  //  int data[]={5,10,90,5};
    rc4.KSA(key);
    int[] text = rc4.PRNG(pixels);
    l.write((int)512,(int)512,text,EnImage);

    //RC4New rc41 = new RC4New();
    rc4.KSA(key);
    int[] text1 = rc4.PRNG(text);
    l.write((int)512,(int)512,text1,DeImage);



 /*   for(int i=0;i<text.length;i++){
        System.out.println(text[i]);
    }

     RC4New rc41 = new RC4New();
     rc4.KSA(key);
    int[] text1 = rc4.PRNG(text); 
     for(int i=0;i<text1.length;i++){
        System.out.println(text1[i]);
    }

   */ 
    System.out.println("length:"+pixels.length);
  //  l.write((int)512,(int)512,text);

    // TODO code application logic here
}
    } 

//加密

 package test;

 /**
     *
 * @author AMaR
 */
 public class RC4New {
 int state[] = new int[256];

 int j;
 /**
 *
 * @param key
 */
public void KSA(int[] key){ 

    int tmp;
    for (int i=0; i < 256; i++) {
        state[i] = i;
    }

    j=0;

    for (int i=0; i < 256; i++) {

       j = (j + state[i] + key[i % key.length]) % 256;
        tmp = state[i];
        state[i] = state[j];
        state[j] = tmp;
    }
}
    public int[] PRNG(int[] data){
    int tmp,k;
    int i=0;
    j=0;
    int[] cipherText = new int[data.length];
    for(int x=0;x<data.length;x++){
        i = (i + 1) % 256;
        j = (j + state[i]) % 256;
        tmp = state[i];
        state[i] = state[j];
        state[j] = tmp;
        k = state[(state[i] + state[j]) % 256];
        cipherText[x]=  (data[x] ^ k);
    }
    return cipherText;



    }


    }

//加载/写入图像

    package test;

    import java.awt.Dimension;
    import java.awt.image.BufferedImage;
    import java.awt.image.Raster;
    import java.io.IOException;
    import javax.imageio.ImageIO;
    import java.io.File;
    import java.awt.image.WritableRaster;
    /**
    *
    * @author AMaR
    */


    public class LoadImage {
      BufferedImage image;
      void load()throws Exception { 

   //  FIle newfile = new File("lena.png)

     image = ImageIO.read(getClass().getResourceAsStream("lena.png"));
    }
    public Dimension getImageSize() {
    return new Dimension(image.getWidth(), image.getHeight());
    }

   public int[] getImagePixels() {
    int [] dummy = null;
    int wid, hgt;

   // compute size of the array
    wid = image.getWidth();
    hgt = image.getHeight();

   // start getting the pixels
   Raster pixelData;
   pixelData = image.getData();
   return pixelData.getPixels(0, 0, wid, hgt, dummy);


   }
    @SuppressWarnings("empty-statement")
   public void write(int width ,int height, int[] pixels,File outputfile) {

       try {
   // retrieve image
    BufferedImage writeImage = new BufferedImage(512, 512, BufferedImage.TYPE_BYTE_GRAY);;
     // File outputfile = new File("encrypted.png");
    WritableRaster raster = (WritableRaster) writeImage.getData();
    raster.setPixels(0,0,width,height,pixels);
    writeImage.setData(raster);
    ImageIO.write(writeImage, "png", outputfile);

    } catch (IOException e) {
      }

     }
    }

推荐答案

不清楚下面哪一个触发您的错误。这个

It's not clear which of the below is triggering your error. This

 File EnImage = new File("encrypted.png");

将从当前目录中读取，这不一定与您的jar文件所在的目录相同。

will read from the current directory, which is not necessarily the same directory as that your jar file is in.

这个

image = ImageIO.read(getClass().getResourceAsStream("lena.png"));

将从您所在类的jar文件中的目录读取。请注意，您正在阅读从的jar文件，而不是目录。

will read from the directory in the jar file that your class is in. Note that you're reading from the jar file, not the directory.

鉴于上述代码，我会：

1. 确定或明确指定 File（）操作的工作目录。您的工作目录是您调用 java 的工作目录，并且可能会在IDE内部/ />>
   
2. 将lena.png打包为您的.jar文件中的资源。

1. determine or explicitly specify the working directory for the File() operations. Your working directory is the one you invoke java from, and this may differ within/without the IDE
2. package the lena.png as a resource within your .jar file.

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