Java Android异步任务运行时异常错误。_Java_Android_Android Intent_Android Listview_Android Asynctask

Java Android异步任务运行时异常错误。

java android

Java Android异步任务运行时异常错误。,java,android,android-intent,android-listview,android-asynctask,Java,Android,Android Intent,Android Listview,Android Asynctask,我在安卓平台上做解密任务。首先，我创建了一个名为RunDecrypt的方法。当我按下UI中的按钮时，它工作正常。方法如下所示： public void runDecrypt() throws IOException{ EditText editText = (EditText) findViewById(R.id.fileName); EditText editText2 = (EditText) findViewById(R.id.keyName); String f

我在安卓平台上做解密任务。首先，我创建了一个名为RunDecrypt的方法。当我按下UI中的按钮时，它工作正常。方法如下所示：

public void runDecrypt() throws IOException{
    EditText editText = (EditText) findViewById(R.id.fileName);
    EditText editText2 = (EditText) findViewById(R.id.keyName);

    String fileName = editText.getText().toString();
    String keyName = editText2.getText().toString();

    File sdcard = Environment.getExternalStorageDirectory();
    File file = new File(sdcard , fileName);
    File key  = new File(sdcard, keyName);


    BufferedReader brFile;
    String Cipher = null;
    try{
        //Read file line by line and concat each line of string in file with space character.
        FileInputStream fstream = new FileInputStream(file);
        brFile = new BufferedReader(new InputStreamReader(fstream));

        String tempString;

        while((tempString = brFile.readLine()) != null){

            if(Cipher == null){
                Cipher = tempString;

            }else{
                Cipher = Cipher.concat(" ");
                Cipher = Cipher.concat(tempString);

            }

        }

    }catch(Exception e){
        //messageBox("Decrypt", e.getMessage());
    }

    BufferedReader brKey;
    String DecKey = null;

    try{
        FileInputStream fstream = new FileInputStream(key);
        brKey = new BufferedReader(new InputStreamReader(fstream));
        DecKey = brKey.readLine();

    }catch(Exception e){
        //messageBox("Decrypt", e.getMessage());
    }


    try{
        byte[] cipherByte = DES.parseBytes(Cipher);
        String decKey = DES.convertStringToHex(DecKey);

        byte[] keyByte = DES.parseBytes(decKey);
        String decryptResult = DES.hex(DES.decryptCBC(cipherByte, keyByte));

        String temp = decryptResult.replace(" ", "");
        String finalDecrypt = temp.substring(0, (temp.length() - DES.getConcatCount()));
        String finResult = DES.convertHexToString(finalDecrypt);

        TextView FinalResult = (TextView)findViewById(R.id.decryptText);
        FinalResult.setText(finResult);

    }catch(Exception e){
        messageBox("Decrypt", "Please Upload File Properly");
    }
}

private class runDecrypt extends AsyncTask <URL , Integer, Long> {
     private final ProgressDialog dialog = new ProgressDialog(Homepage.this);
     AlertDialog.Builder builder = new AlertDialog.Builder(Homepage.this);
    @SuppressWarnings("resource")
    @Override
    protected Long doInBackground(URL... params) {
        EditText editText = (EditText) findViewById(R.id.fileName);
        EditText editText2 = (EditText) findViewById(R.id.keyName);

        String fileName = editText.getText().toString();
        String keyName = editText2.getText().toString();

        File sdcard = Environment.getExternalStorageDirectory();
        File file = new File(sdcard , fileName);
        File key  = new File(sdcard, keyName);


        BufferedReader brFile;
        String Cipher = null;
        try{
            //Read file line by line and concat each line of string in file with space character.
            FileInputStream fstream = new FileInputStream(file);
            brFile = new BufferedReader(new InputStreamReader(fstream));

            String tempString;

            try {
                while((tempString = brFile.readLine()) != null){

                    if(Cipher == null){
                        Cipher = tempString;

                    }else{
                        Cipher = Cipher.concat(" ");
                        Cipher = Cipher.concat(tempString);

                    }

                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }catch(java.io.FileNotFoundException e){
            System.out.println("File could not be found.");
        }

        BufferedReader brKey;
        String DecKey = null;
        try{
            FileInputStream fstream = new FileInputStream(key);
            brKey = new BufferedReader(new InputStreamReader(fstream));
            try {
                DecKey = brKey.readLine();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }catch(java.io.FileNotFoundException e){
            System.out.println("Key file could not be found.");
        }

        String decKey = DES.convertStringToHex(DecKey);     
        byte[] cipherByte = DES.parseBytes(Cipher);
        byte[] keyByte = DES.parseBytes(decKey);
        String decryptResult = DES.hex(DES.decryptCBC(cipherByte, keyByte));

        String temp = decryptResult.replace(" ", "");
        String finalDecrypt = temp.substring(0, (temp.length() - DES.getConcatCount()));
        String finResult = DES.convertHexToString(finalDecrypt);

        TextView FinalResult = (TextView)findViewById(R.id.decryptText);
        FinalResult.setText(finResult);
        return null;
    }
    protected void onPreExecute() {
         this.dialog.setMessage("Decrypting...");
         this.dialog.show();
      }

    protected void onPostExecute(Long result) {

        if (this.dialog.isShowing()) {
            this.dialog.dismiss();
         }
        builder.setMessage("Decryption Completed");
        builder.show();

    }
    protected void onProgressUpdate(int progress) {
        setProgress(progress * 100);
    }
}

由于工作正常，我尝试使用异步任务来实现此方法，以便在后台运行我的工作。实现的类如下所示：

public void runDecrypt() throws IOException{
    EditText editText = (EditText) findViewById(R.id.fileName);
    EditText editText2 = (EditText) findViewById(R.id.keyName);

    String fileName = editText.getText().toString();
    String keyName = editText2.getText().toString();

    File sdcard = Environment.getExternalStorageDirectory();
    File file = new File(sdcard , fileName);
    File key  = new File(sdcard, keyName);


    BufferedReader brFile;
    String Cipher = null;
    try{
        //Read file line by line and concat each line of string in file with space character.
        FileInputStream fstream = new FileInputStream(file);
        brFile = new BufferedReader(new InputStreamReader(fstream));

        String tempString;

        while((tempString = brFile.readLine()) != null){

            if(Cipher == null){
                Cipher = tempString;

            }else{
                Cipher = Cipher.concat(" ");
                Cipher = Cipher.concat(tempString);

            }

        }

    }catch(Exception e){
        //messageBox("Decrypt", e.getMessage());
    }

    BufferedReader brKey;
    String DecKey = null;

    try{
        FileInputStream fstream = new FileInputStream(key);
        brKey = new BufferedReader(new InputStreamReader(fstream));
        DecKey = brKey.readLine();

    }catch(Exception e){
        //messageBox("Decrypt", e.getMessage());
    }


    try{
        byte[] cipherByte = DES.parseBytes(Cipher);
        String decKey = DES.convertStringToHex(DecKey);

        byte[] keyByte = DES.parseBytes(decKey);
        String decryptResult = DES.hex(DES.decryptCBC(cipherByte, keyByte));

        String temp = decryptResult.replace(" ", "");
        String finalDecrypt = temp.substring(0, (temp.length() - DES.getConcatCount()));
        String finResult = DES.convertHexToString(finalDecrypt);

        TextView FinalResult = (TextView)findViewById(R.id.decryptText);
        FinalResult.setText(finResult);

    }catch(Exception e){
        messageBox("Decrypt", "Please Upload File Properly");
    }
}

private class runDecrypt extends AsyncTask <URL , Integer, Long> {
     private final ProgressDialog dialog = new ProgressDialog(Homepage.this);
     AlertDialog.Builder builder = new AlertDialog.Builder(Homepage.this);
    @SuppressWarnings("resource")
    @Override
    protected Long doInBackground(URL... params) {
        EditText editText = (EditText) findViewById(R.id.fileName);
        EditText editText2 = (EditText) findViewById(R.id.keyName);

        String fileName = editText.getText().toString();
        String keyName = editText2.getText().toString();

        File sdcard = Environment.getExternalStorageDirectory();
        File file = new File(sdcard , fileName);
        File key  = new File(sdcard, keyName);


        BufferedReader brFile;
        String Cipher = null;
        try{
            //Read file line by line and concat each line of string in file with space character.
            FileInputStream fstream = new FileInputStream(file);
            brFile = new BufferedReader(new InputStreamReader(fstream));

            String tempString;

            try {
                while((tempString = brFile.readLine()) != null){

                    if(Cipher == null){
                        Cipher = tempString;

                    }else{
                        Cipher = Cipher.concat(" ");
                        Cipher = Cipher.concat(tempString);

                    }

                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }catch(java.io.FileNotFoundException e){
            System.out.println("File could not be found.");
        }

        BufferedReader brKey;
        String DecKey = null;
        try{
            FileInputStream fstream = new FileInputStream(key);
            brKey = new BufferedReader(new InputStreamReader(fstream));
            try {
                DecKey = brKey.readLine();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }catch(java.io.FileNotFoundException e){
            System.out.println("Key file could not be found.");
        }

        String decKey = DES.convertStringToHex(DecKey);     
        byte[] cipherByte = DES.parseBytes(Cipher);
        byte[] keyByte = DES.parseBytes(decKey);
        String decryptResult = DES.hex(DES.decryptCBC(cipherByte, keyByte));

        String temp = decryptResult.replace(" ", "");
        String finalDecrypt = temp.substring(0, (temp.length() - DES.getConcatCount()));
        String finResult = DES.convertHexToString(finalDecrypt);

        TextView FinalResult = (TextView)findViewById(R.id.decryptText);
        FinalResult.setText(finResult);
        return null;
    }
    protected void onPreExecute() {
         this.dialog.setMessage("Decrypting...");
         this.dialog.show();
      }

    protected void onPostExecute(Long result) {

        if (this.dialog.isShowing()) {
            this.dialog.dismiss();
         }
        builder.setMessage("Decryption Completed");
        builder.show();

    }
    protected void onProgressUpdate(int progress) {
        setProgress(progress * 100);
    }
}

我的日志如下所示：

有人能帮忙吗？谢谢，谢谢

您的代码存在各种问题，但特定异常的原因已在Logcat中解释：

只有创建视图层次结构的原始线程才能接触其视图

所讨论的行是

com.example.descracker.Homepage:245

，在这里您可以从异步任务对文本视图调用

setText（）

。您必须将此逻辑移动到UI线程中，例如通过AsyncTask的工具函数

onPreExecute（）

，

onPostExecute（）

或

onProgressUpdate（）

，或者通过使用

post（Runnable）

向视图本身发布延迟操作

另外，请遵循Java编码惯例，并以小写字母开头变量名称。

正如Shashank kadhe所提到的，在onPostExecute方法中尝试此方法，并请根据自己的需要进行更改

protected void onPostExecute(String file_url) {

String fileName = editText.getText().toString();
        String keyName = editText2.getText().toString();

        File sdcard = Environment.getExternalStorageDirectory();
        File file = new File(sdcard , fileName);
        File key  = new File(sdcard, keyName);

BufferedReader brFile;
    String Cipher = null;
    try{
        //Read file line by line and concat each line of string in file with space character.
        FileInputStream fstream = new FileInputStream(file);
        brFile = new BufferedReader(new InputStreamReader(fstream));

        String tempString;

        while((tempString = brFile.readLine()) != null){

            if(Cipher == null){
                Cipher = tempString;

            }else{
                Cipher = Cipher.concat(" ");
                Cipher = Cipher.concat(tempString);

            }

        }

    }catch(Exception e){
        //messageBox("Decrypt", e.getMessage());
    }

    BufferedReader brKey;
    String DecKey = null;

    try{
        FileInputStream fstream = new FileInputStream(key);
        brKey = new BufferedReader(new InputStreamReader(fstream));
        DecKey = brKey.readLine();

    }catch(Exception e){
        //messageBox("Decrypt", e.getMessage());
    }


    try{
        byte[] cipherByte = DES.parseBytes(Cipher);
        String decKey = DES.convertStringToHex(DecKey);

        byte[] keyByte = DES.parseBytes(decKey);
        String decryptResult = DES.hex(DES.decryptCBC(cipherByte, keyByte));

        String temp = decryptResult.replace(" ", "");
        String finalDecrypt = temp.substring(0, (temp.length() - DES.getConcatCount()));
        String finResult = DES.convertHexToString(finalDecrypt);

        TextView FinalResult = (TextView)findViewById(R.id.decryptText);
        FinalResult.setText(finResult);

    }catch(Exception e){
        messageBox("Decrypt", "Please Upload File Properly");
    }
}

Since it's work fine, I try to implement this method with Async Task for running my work in background. The class that implemented shown below:

private class runDecrypt extends AsyncTask <URL , Integer, Long> {
     private final ProgressDialog dialog = new ProgressDialog(Homepage.this);
     AlertDialog.Builder builder = new AlertDialog.Builder(Homepage.this);
    @SuppressWarnings("resource")
    @Override
    protected Long doInBackground(URL... params) {
        EditText editText = (EditText) findViewById(R.id.fileName);
        EditText editText2 = (EditText) findViewById(R.id.keyName);

        String fileName = editText.getText().toString();
        String keyName = editText2.getText().toString();

        File sdcard = Environment.getExternalStorageDirectory();
        File file = new File(sdcard , fileName);
        File key  = new File(sdcard, keyName);


        BufferedReader brFile;
        String Cipher = null;
        try{
            //Read file line by line and concat each line of string in file with space character.
            FileInputStream fstream = new FileInputStream(file);
            brFile = new BufferedReader(new InputStreamReader(fstream));

            String tempString;

            try {
                while((tempString = brFile.readLine()) != null){

                    if(Cipher == null){
                        Cipher = tempString;

                    }else{
                        Cipher = Cipher.concat(" ");
                        Cipher = Cipher.concat(tempString);

                    }

                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }catch(java.io.FileNotFoundException e){
            System.out.println("File could not be found.");
        }

        BufferedReader brKey;
        String DecKey = null;
        try{
            FileInputStream fstream = new FileInputStream(key);
            brKey = new BufferedReader(new InputStreamReader(fstream));
            try {
                DecKey = brKey.readLine();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }catch(java.io.FileNotFoundException e){
            System.out.println("Key file could not be found.");
        }

        String decKey = DES.convertStringToHex(DecKey);     
        byte[] cipherByte = DES.parseBytes(Cipher);
        byte[] keyByte = DES.parseBytes(decKey);
        String decryptResult = DES.hex(DES.decryptCBC(cipherByte, keyByte));

        String temp = decryptResult.replace(" ", "");
        String finalDecrypt = temp.substring(0, (temp.length() - DES.getConcatCount()));
        String finResult = DES.convertHexToString(finalDecrypt);

        TextView FinalResult = (TextView)findViewById(R.id.decryptText);
        FinalResult.setText(finResult);
}
}

受保护的void onPostExecute（字符串文件\u url）{
字符串文件名=editText.getText（）.toString（）；
String keyName=editText2.getText（）.toString（）；
文件sdcard=Environment.getExternalStorageDirectory（）；
文件文件=新文件（SD卡，文件名）；
文件密钥=新文件（SD卡，密钥名）；
缓冲读取文件；
字符串密码=null；
试一试{
//逐行读取文件，并用空格字符表示文件中字符串的每一行。
FileInputStream fstream=新的FileInputStream（文件）；
brFile=新的BufferedReader（新的InputStreamReader（fstream））；
字符串tempString；
而（（tempString=brFile.readLine（））！=null）{
如果（密码==null）{
密码=临时字符串；
}否则{
密码=Cipher.concat（“”）；
Cipher=Cipher.concat（tempString）；
}
}
}捕获（例外e）{
//messageBox（“Decrypt”，例如getMessage（））；
}
缓冲读取键；
String DecKey=空；
试一试{
FileInputStream fstream=新的FileInputStream（键）；
brKey=新的BufferedReader（新的InputStreamReader（fstream））；
DecKey=brKey.readLine（）；
}捕获（例外e）{
//messageBox（“Decrypt”，例如getMessage（））；
}
试一试{
字节[]cipherByte=DES.parseBytes（密码）；
字符串decKey=DES.convertStringToHex（decKey）；
byte[]keyByte=DES.parseBytes（decKey）；
字符串decryptResult=DES.hex（DES.decryptCBC（cipherByte，keyByte））；
字符串temp=decryptResult.replace（“，”）；
字符串finalDecrypt=temp.substring（0，（temp.length（）-DES.getConcatCount（））；
字符串finResult=DES.convertexhtostring（finalDecrypt）；
TextView FinalResult=（TextView）findViewById（R.id.decryptText）；
FinalResult.setText（finResult）；
}捕获（例外e）{
messageBox（“解密”，“请正确上传文件”）；
}
}
由于工作正常，我尝试使用异步任务来实现此方法，以便在后台运行我的工作。实现的类如下所示：
私有类runDecrypt扩展异步任务{
private final ProgressDialog=新建ProgressDialog（主页.this）；
AlertDialog.Builder=新建AlertDialog.Builder（Homepage.this）；
@抑制警告（“资源”）
@凌驾
受保护的长doInBackground（URL…参数）{
EditText EditText=（EditText）findViewById（R.id.fileName）；
EditText editText2=（EditText）findViewById（R.id.keyName）；
字符串文件名=editText.getText（）.toString（）；
String keyName=editText2.getText（）.toString（）；
文件sdcard=Environment.getExternalStorageDirectory（）；
文件文件=新文件（SD卡，文件名）；
文件密钥=新文件（SD卡，密钥名）；
缓冲读取文件；
字符串密码=null；
试一试{
//逐行读取文件，并用空格字符表示文件中字符串的每一行。
FileInputStream fstream=新的FileInputStream（文件）；
brFile=新的BufferedReader（新的InputStreamReader（fstream））；
字符串tempString；
试一试{
而（（tempString=brFile.readLine（））！=null）{
如果（密码==null）{
密码=临时字符串；
}否则{
密码=Cipher.concat（“”）；
Cipher=Cipher.concat（tempString）；
}
}
}捕获（IOE异常）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}
}catch（java.io.filenotfound异常）{
System.out.println（“找不到文件”）；
}
缓冲读取键；
字符串DecKey=null；
试一试{
FileInputStream fstream=新的FileInputStream（键）；
brKey=新的BufferedReader（新的InputStreamReader（fstream））；
试一试{
DecKey=brKey.readLine（）；
}捕获（IOE异常）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}
}catch（java.io.filenotfound异常）{
System.out.println（“找不到密钥文件”）；
}
字符串decKey=DES.convertStringToHex（decKey）；
字节[]cipherByte=DES.parseBytes（密码）；
byte[]keyByte=DES.parseBytes（decKey）；
字符串decryptResult=DES.hex（DES.decryptCBC（cipherByte，keyByte））；
字符串temp=decryptResult.replace（“，”）；
字符串finalDecrypt=temp.substring（0，（temp.length（）-DES.getConcatCount（））；