内存不足错误，而加密

Question

首先，这是我得到

java.lang.OutOfMemoryError 
at coderaustin.com.FileEncryptor.encryptFile(FileEncryptor.java:56) 
at coderaustin.com.Main.onCreate(Main.java:41) 
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1069) 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2751) 
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2803) 
at android.app.ActivityThread.access$2300(ActivityThread.java:135) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2136) 
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loop(Looper.java:144) 
at android.app.ActivityThread.main(ActivityThread.java:4937) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:521) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
at dalvik.system.NativeStart.main(Native Method) 

错误很明显，我知道是什么错误，我只是不知道如何避免它。这是我的应用程序，

您选择一个文件，然后单击加密。所以显然从那里它需要的文件，并使用此代码加密

try { 
    FileInputStream inFile = new FileInputStream(f.getAbsolutePath()); 
    FileOutputStream outFile = new FileOutputStream(f.getAbsoluteFile() + ".des"); 

    PBEKeySpec keySpec = new PBEKeySpec(text.toCharArray()); 
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES"); 
    SecretKey passwordKey = keyFactory.generateSecret(keySpec); 
    byte[] salt = new byte[8]; 
    Random rnd = new Random(); 
    rnd.nextBytes(salt); 
    int iterations = 100; 

    PBEParameterSpec paramaterSpec = new PBEParameterSpec(salt, iterations); 

    Cipher cipher = Cipher.getInstance("PBEWithMD5AndDES"); 
    cipher.init(Cipher.ENCRYPT_MODE, passwordKey, paramaterSpec); 

    outFile.write(salt); 



    byte[] input = new byte[inFile.available()]; 

    int bytesRead; 
    while ((bytesRead = inFile.read(input)) != -1) 
       { 
        byte[] output = cipher.update(input, 0, bytesRead); 
        if (output != null) outFile.write(output); 
       } 

       byte[] output = cipher.doFinal(); 
       if (output != null) outFile.write(output); 
       f.delete(); 
       inFile.close(); 
       outFile.flush(); 
       outFile.close(); 

是的我知道代码是非常丑陋的，但它的工作原理。有什么建议么？

感谢所有:)

编辑：这是行56

byte[] input = new byte[inFile.available()];

Answer 1

奇：如果该文件是非常大的，我可以看到，可能是一个问题。你为什么一次读取整个文件，而不是以小块和处理方式读取它？

编辑：试试这个。

byte[] input = new byte[4096]; 

    int bytesRead; 
    while ((bytesRead = inFile.read(input, 0, 4096)) != -1) 
       { 
        byte[] output = cipher.update(input, 0, bytesRead); 
        if (output != null) outFile.write(output); 
       }