package de.thedevstack.android.logcat.tasks;
import android.os.AsyncTask;
import android.widget.ArrayAdapter;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import de.thedevstack.android.logcat.Logging;
import de.thedevstack.android.logcat.adapters.LogCatArrayAdapter;
/**
* Task to read the logcat of the App.
* The command logcat -d -v time
is used to load the logs.
* This reader uses a white list to restrict the messages to display, otherwise it might be flooded with useless log messages.
* The white list checks if a log messages contains one of the following strings:
*
* - {@value Logging#LOG_TAG_PREFIX}
* E/
- for every error message
* W/
- for every warning message
*
*/
public class ReadLogCatAsyncTask extends AsyncTask {
/**
* The array adapter to publish the log messages to.
*/
private final LogCatArrayAdapter arrayAdapter;
/**
* The command to execute logcat.
*/
private static final String[] LOG_CAT_CMD = { "logcat", "-d", "-v", "time"};
/**
* The white list to filter log messages.
*/
private static final String[] WHITE_LIST = { Logging.getLogTagPrefix(), "E/", "W/" };
/**
* Initializes the Task with the array adapter to publish the log messages to.
* @param arrayAdapter the array adapter
*/
public ReadLogCatAsyncTask(LogCatArrayAdapter arrayAdapter) {
this.arrayAdapter = arrayAdapter;
}
/**
* Executes the logcat command, reads the output of the command and returns all log messages.
* @param params no params will be passed. (interface compliance)
* @return the array of log messages
*/
@Override
protected String[] doInBackground(Void... params) {
ArrayList logCatOutput = new ArrayList<>();
BufferedReader bufferedReader = null;
BufferedReader errorReader = null;
try {
Process process = Runtime.getRuntime().exec(ReadLogCatAsyncTask.LOG_CAT_CMD);
bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
errorReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
String line = "";
while ((line = bufferedReader.readLine()) != null) {
logCatOutput.add(line);
}
String errorLine = "";
StringBuilder sb = new StringBuilder();
while ((errorLine = errorReader.readLine()) != null) {
sb.append(errorLine);
sb.append('\n');
}
int exitValue = process.waitFor();
Logging.d("ReadLogCat", "Logcat command returned with exitValue '" + exitValue + "'.");
String errorMessage = sb.toString();
if (0 != exitValue && !errorMessage.isEmpty()) {
Logging.e("ReadLogCat", errorMessage);
logCatOutput.add(errorMessage);
}
} catch (IOException e) {
Logging.e("ReadLogCat", "error while retrieving information from logcat: " + e.getMessage(), e);
} catch (InterruptedException e) {
Logging.e("ReadLogCat", "error while retrieving information from logcat: " + e.getMessage(), e);
} finally {
if (null != bufferedReader) {
try {
bufferedReader.close();
} catch (IOException e) {
}
}
if (null != errorReader) {
try {
errorReader.close();
} catch (IOException e) {
}
}
}
logCatOutput.trimToSize();
return logCatOutput.toArray(new String[0]);
}
/**
* Clears the array adapter and adds the filtered log messages.
* @param items all log messages
*/
@Override
protected void onPostExecute(String[] items) {
this.arrayAdapter.clear();
if (null != items && items.length > 0) {
for (String item : items) {
if (!filter(item)) {
this.arrayAdapter.add(item);
}
}
}
}
/**
* Checks whether a log message contains a white listed string or not.
* @param item the item to filter
* @return true
if the string should be filtered (removed from the list) false
otherwise.
*/
protected boolean filter(String item) {
for (String whiteListed : ReadLogCatAsyncTask.WHITE_LIST) {
if (item.contains(whiteListed)) {
return false;
}
}
return true;
}
}