java - 加密时出现 OutOfMemory 错误

Question

首先，这是我遇到的错误

   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)

显然我知道错误是什么，我只是不知道如何避免它。这就是我的应用程序所做的，

您选择一个文件，然后单击“加密”。很明显，它从那里获取文件，并使用此代码对其进行加密

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，我知道代码很丑陋，但它确实有效。有什么建议吗？

谢谢大家:)

编辑:这是第 56 行

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

Answer 1

奇怪:如果文件很大，我可以看出这可能是个问题。为什么要一次读取整个文件，而不是分小块读取和处理？

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);
               }