Reputation: 4029
I installed Android Studio yesterday, and I tried to use the LogCat to see the logs. But there is nothing to show in the logcat. I used the terminal to run ./adb logcat
and it works.
Is there someone who can explain to me how to use logcat in Android Studio?
Upvotes: 368
Views: 338386
Reputation: 471
Upon running adb logcat, I realised that the emulator wouldn't show any logs unless it was the only device connected to Android Studio. I simply unplugged the other connected testing devices and it started running flawlessly.
Upvotes: 0
Reputation: 394
open the terminal and type adb logcat make sure you have one device connected.
Upvotes: 0
Reputation: 119
Check the LogCat Sitteng in My case i Uncheck every thing which make issu from me
Again i check everything which works for me
Upvotes: 0
Reputation: 37
Make sure you have selected the correct emulator and that field right next to emulator selector is not empty (in the Logcat console).
Upvotes: 0
Reputation: 76962
For me disabling Verify apps over USB and Verify bytecode of debuggable apps helped me to make the logcat much more reliable.
Upvotes: 1
Reputation: 688
if you use Android Emulator, you can Wipe Data then start the emulator again. only this work for me
Upvotes: 0
Reputation: 850
Disable and uninstall any plugins that you have recently installed and are not using.
Upvotes: 0
Reputation: 1708
Also be careful for this bad boy (even with Restart of android studio not disappeared):
Upvotes: 2
Reputation: 144
Check for space in the log-tag. If your tag consist of spaces then remove the space and then run. You will be able to view logs.
Upvotes: 0
Reputation: 689
When everything else didn't work, here's what I did. Since adb logcat
worked nicely, I decided to rely on it. Running adb logcat -v color
in the Android Studio's embedded terminal produced outputs similar to the normal logcat, and allowed code links to work too:
But this came with a few issues:
--pid=<your PID>
option, you can watch the output of a single process. But since every time you restart your app the PID changes, you have re-run this command with every restart.So I decided to make my own tool to automatically watch my package PID(s) and prettify the logcat output:
import java.awt.AWTException;
import java.io.*;
import java.util.ArrayList;
import java.awt.Robot;
import java.awt.event.KeyEvent;
public class Logcat {
private static final String ADB_FILE_PATH = "adb";
// Customizations,
private static final Color V_COLOR = Color.RESET;
private static final Color D_COLOR = Color.RESET;
private static final Color I_COLOR = Color.RESET;
private static final Color W_COLOR = Color.BLUE;
private static final Color E_COLOR = Color.RED_BRIGHT;
private static final Color HINT_COLOR = Color.MAGENTA_BOLD_BRIGHT;
private static final Color OTHER_COLOR = Color.GREEN_BOLD_BRIGHT;
private static final int DATE_LENGTH = 5;
private static final int TIME_LENGTH = 12;
private static final int PROCESS_ID_LENGTH = 5;
private static final int THREAD_ID_LENGTH = 5;
private static final int LOG_LEVEL_LENGTH = 1;
private static final int TAG_LENGTH = 20;
private static final int MESSAGE_LENGTH = 110;
private static final String SEPARATOR = " | ";
private static final String CONTINUATION = "→";
private static final String INDENTATION = " ";
private static final int PROCESS_IDS_UPDATE_INTERVAL_MILLIS = 1224;
private static final int HISTORY_LENGTH = 1000;
// State,
private static boolean skipProcessIDCheck;
private static ArrayList<String> processIDs = new ArrayList<String>();
private static String logLevelToShow="V"; // All.
private static Process logcatProcess;
private static boolean appClosed;
private static boolean stopEverything;
private static String[] history = new String[HISTORY_LENGTH];
private static int currentLocationInHistory, historyLength;
public static void main(final String args[]) {
clearAndroidStudioConsole();
System.out.println("besm Allah");
// Get processes ids of the provided package,
if (args.length==0) {
skipProcessIDCheck = true;
} else {
skipProcessIDCheck = false;
getProcessIDs (args[0]); // Do it once before we start.
monitorProcessIDs(args[0]); // Do it periodically from now on.
}
// Start capturing and prettifying logcat,
if (!monitorLogcat()) {
stopEverything = true;
return;
}
// Handle user input,
handleUserInput();
}
private static void watch(final Process process, final ProcessListener listener) {
// Read process standard output and send it to the listener line by line,
new Thread() {
public void run() {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = "";
try {
do {
if (bufferedReader.ready()) {
line = bufferedReader.readLine();
if (line!=null && !line.isEmpty()) listener.onNewLine(line);
} else {
Thread.sleep(100);
}
} while (line!=null && !stopEverything);
} catch (Exception e) { e.printStackTrace(); }
}
}.start();
}
private static void monitorProcessIDs(String packageName) {
// Continuously monitor the process IDs of this package and update when changed,
new Thread() {
public void run() {
do {
try { Thread.sleep(PROCESS_IDS_UPDATE_INTERVAL_MILLIS); } catch (InterruptedException e) {}
getProcessIDs(packageName);
} while (!stopEverything);
}
}.start();
}
private static void getProcessIDs(String packageName) {
// Get the process IDs associated with this package once,
ArrayList<String> newProcessIDs = new ArrayList<String>();
Runtime runtime = Runtime.getRuntime();
try {
Process getPIDProcess = runtime.exec(ADB_FILE_PATH + " shell ps");
watch(getPIDProcess, (line) -> {
if (line.contains(packageName)) {
newProcessIDs.add(removeRedundantSpaces(line).split(" ")[1]);
}
});
getPIDProcess.waitFor();
Thread.sleep(500); // Make sure we've already handled all the input from the process.
} catch (Exception e) { e.printStackTrace(); }
// Return immediately if program is closed,
if (stopEverything) return ;
// Some action upon getting the pid(s),
boolean shouldRepeatHistory = false;
if (newProcessIDs.isEmpty()) {
// Just closed,
if (!appClosed) {
appClosed = true;
prettify("----- App closed -----");
}
} else if (appClosed) {
// Just opened, clear,
appClosed = false;
clearAndroidStudioConsole();
prettify("----- App opened -----");
shouldRepeatHistory = true;
} else {
// Detect changes in processes,
for (String pid : newProcessIDs) {
if (!processIDs.contains(pid)) {
clearAndroidStudioConsole();
prettify("----- Process(es) changed (or app restarted - some logs could have been missed) -----");
shouldRepeatHistory = true;
break ;
}
}
}
// Set the new PID(s),
processIDs = newProcessIDs;
if (shouldRepeatHistory) repeatHistory();
}
private static boolean monitorLogcat() {
Runtime runtime = Runtime.getRuntime();
try {
logcatProcess = runtime.exec(ADB_FILE_PATH + " logcat -v threadtime");
watch(logcatProcess, (line) -> {
// Learn history, in case we need to repeat it,
if (appClosed || processLogcatLine(line)) {
history[currentLocationInHistory] = line;
currentLocationInHistory = (currentLocationInHistory + 1) % history.length;
if (historyLength<history.length) historyLength++;
}
});
} catch (Exception e) {
e.printStackTrace();
return false;
}
return true;
}
private static boolean processLogcatLine(String line) {
try {
return prettify(line);
} catch (Exception e) {
print(line, OTHER_COLOR);
System.out.println();
// Debug,
e.printStackTrace();
return true;
}
}
// Returns true if line should be kept in history,
private static synchronized boolean prettify(String line) {
if (line.startsWith("-")) {
// It's a "beginning of <something>" line,
print(line, HINT_COLOR);
System.out.println();
return true;
}
// Get the individual fields,
String date = line.substring(0, line.indexOf(' ')); line = line.substring(line.indexOf(' ')+1); line = line.trim();
String time = line.substring(0, line.indexOf(' ')); line = line.substring(line.indexOf(' ')+1); line = line.trim();
String processID = line.substring(0, line.indexOf(' ')); line = line.substring(line.indexOf(' ')+1); line = line.trim();
// Break early if possible,
if (!skipProcessIDCheck && !processIDs.contains(processID.trim())) return false;
// Continue parsing,
String threadID = line.substring(0, line.indexOf(' ')); line = line.substring(line.indexOf(' ')+1); line = line.trim();
String logLevel = line.substring(0, line.indexOf(' ')); line = line.substring(line.indexOf(' ')+1); line = line.trim();
// Break early if possible,
switch (logLevel) {
case "V": if (!"V" .contains(logLevelToShow)) return true; break;
case "D": if (!"VD" .contains(logLevelToShow)) return true; break;
case "I": if (!"VDI" .contains(logLevelToShow)) return true; break;
case "W": if (!"VDIW" .contains(logLevelToShow)) return true; break;
case "E": if (!"VDIWE".contains(logLevelToShow)) return true; break;
}
// Continue parsing,
String tag = line.substring(0, line.indexOf(':')); line = line.substring(line.indexOf(':')+1); line = line.trim();
// Because some tags have a trailing ":",
if (line.startsWith(":")) {
tag += ":";
line = line.substring(1);
}
// Indent lines starting by "at",
String indentation = "";
if (line.startsWith("at ")) {
indentation = " " + INDENTATION;
line = " " + INDENTATION + line;
}
// Print the prettified log,
Color color;
switch (logLevel) {
case "V": color = V_COLOR; break;
case "D": color = D_COLOR; break;
case "I": color = I_COLOR; break;
case "W": color = W_COLOR; break;
case "E": color = E_COLOR; break;
default:
color = Color.RESET;
}
String fields = adjustLength( date, DATE_LENGTH) + SEPARATOR +
adjustLength( time, TIME_LENGTH) + SEPARATOR +
adjustLength(processID, PROCESS_ID_LENGTH) + SEPARATOR +
adjustLength( threadID, THREAD_ID_LENGTH) + SEPARATOR +
adjustLength( logLevel, LOG_LEVEL_LENGTH) + SEPARATOR +
adjustLength( tag, TAG_LENGTH) + SEPARATOR;
// Split the message onto multiple lines if needed,
String message = chunkPreservingParentheses(line, MESSAGE_LENGTH, 2);
print(fields + message, color);
System.out.println();
while (line.length() > message.length()) {
// Debug,
//print(line, OTHER_COLOR);
//System.out.println("Line: " + line.length() + "length: " + message.length() + ", cont: " + CONTINUATION.length() + "dent: " + indentation.length());
//System.out.println();
// Remove the already printed part.
line = line.substring(message.length()-CONTINUATION.length());
// Add a dot to make links work,
boolean shouldAddDot=false;
if (line.matches("^[^\\.]*\\(.*:[123456789][1234567890]*\\).*")) shouldAddDot = true;
// Indent,
line = (shouldAddDot ? "." : (indentation.isEmpty() ? "" : " ")) + indentation + line;
// Take another chunk,
message = chunkPreservingParentheses(line, MESSAGE_LENGTH, 2+indentation.length());
// Front pad to align this part with the message body,
String paddedMessage = message;
for (int i=0; i<fields.length(); i++) paddedMessage = ' ' + paddedMessage;
// Print,
print(paddedMessage, color);
System.out.println();
}
return true; // Keep in local buffer.
}
private static String adjustLength(String text, int length) {
while (text.length() < length) text += ' ';
if (text.length() > length) {
text = text.substring(0, length-CONTINUATION.length());
text += CONTINUATION;
}
return text;
}
private static String chunkPreservingParentheses(String text, int length, int minChunckLength) {
if (text.length() <= length) return text;
// Take a chunk out of the text,
String chunk = text.substring(0, length-CONTINUATION.length()) + CONTINUATION;
// Check if a paranthesis was opened and not closed,
int lastOpenParanthesisIndex = chunk.lastIndexOf('(');
int lastCloseParanthesisIndex = chunk.lastIndexOf(')');
if (lastCloseParanthesisIndex <= lastOpenParanthesisIndex) { // Also works when either is not found.
if (minChunckLength<1) minChunckLength = 1;
if (lastOpenParanthesisIndex > minChunckLength+CONTINUATION.length()) { // Avoid endless loops.
int includeParenthesisSize = (CONTINUATION.length()>0) ? 1 : 0;
chunk = text.substring(0, lastOpenParanthesisIndex+includeParenthesisSize-CONTINUATION.length()) + CONTINUATION;
}
}
return chunk;
}
private static void repeatHistory() {
int index = currentLocationInHistory-historyLength;
if (index < 0) index += history.length;
for (int i=0; i<historyLength; i++) {
processLogcatLine(history[index]);
index = (index + 1) % history.length;
}
}
private static void print(String text, Color color) {
System.out.print(color);
System.out.print(text);
System.out.print(Color.RESET);
}
private static String removeRedundantSpaces(String text) {
String newText = text.replace(" ", " ");
while (!text.equals(newText)) {
text = newText;
newText = text.replace(" ", " ");
}
return text;
}
private static void clearAndroidStudioConsole() {
// Couldn't find a reliable way to clear Intellij terminal scrollback, so we just print
// a LOT of newlines,
StringBuilder bunchOfNewLines = new StringBuilder();
for (int i=0; i<124; i++) bunchOfNewLines.append(System.lineSeparator());
System.out.print(bunchOfNewLines);
// Scroll the current line to the top of the window,
try {
// If we are on Windows,
new ProcessBuilder("cmd", "/c", "cls").inheritIO().start().waitFor();
} catch (Exception e) {
// We are not on Windows,
bunchOfNewLines = new StringBuilder();
for (int i=0; i<124; i++) bunchOfNewLines.append("\b\r");
System.out.print(bunchOfNewLines);
}
}
private static void handleUserInput() {
// Line read. Unfortunately, java doesn't provide character by character reading out of the box.
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
String input = "";
do {
try {
if (bufferedReader.ready()) {
input = input = bufferedReader.readLine().toUpperCase();
// Set log level,
if (input.equals("V")||input.equals("D")||input.equals("I")||input.equals("W")||input.equals("E")) {
if (!logLevelToShow.equals(input)) {
logLevelToShow = input;
clearAndroidStudioConsole();
repeatHistory();
}
prettify("----- Log level set to " + logLevelToShow + " -----");
} else if (input.equals("C")) {
// Clear screen and history,
clearAndroidStudioConsole();
historyLength = 0;
}
} else {
Thread.sleep(100);
}
} catch (Exception e) { e.printStackTrace(); }
// Check if the logcat process is still alive,
if (!logcatProcess.isAlive()) {
prettify("----- adb logcat process terminated -----");
stopEverything = true;
}
} while (!stopEverything && !input.equals("Q"));
// Allow all monitoring threads to exit,
stopEverything = true;
}
interface ProcessListener {
void onNewLine(String line);
}
enum Color {
// Thanks to this answer: https://stackoverflow.com/a/51944613/1942069
//Color end string, color reset
RESET("\033[0m"),
// Regular Colors. Normal color, no bold, background color etc.
BLACK ("\033[0;30m"),
RED ("\033[0;31m"),
GREEN ("\033[0;32m"),
YELLOW ("\033[0;33m"),
BLUE ("\033[0;34m"),
MAGENTA("\033[0;35m"),
CYAN ("\033[0;36m"),
WHITE ("\033[0;37m"),
// Bold
BLACK_BOLD ("\033[1;30m"),
RED_BOLD ("\033[1;31m"),
GREEN_BOLD ("\033[1;32m"),
YELLOW_BOLD ("\033[1;33m"),
BLUE_BOLD ("\033[1;34m"),
MAGENTA_BOLD("\033[1;35m"),
CYAN_BOLD ("\033[1;36m"),
WHITE_BOLD ("\033[1;37m"),
// Underline
BLACK_UNDERLINED ("\033[4;30m"),
RED_UNDERLINED ("\033[4;31m"),
GREEN_UNDERLINED ("\033[4;32m"),
YELLOW_UNDERLINED ("\033[4;33m"),
BLUE_UNDERLINED ("\033[4;34m"),
MAGENTA_UNDERLINED("\033[4;35m"),
CYAN_UNDERLINED ("\033[4;36m"),
WHITE_UNDERLINED ("\033[4;37m"),
// Background
BLACK_BACKGROUND ("\033[40m"),
RED_BACKGROUND ("\033[41m"),
GREEN_BACKGROUND ("\033[42m"),
YELLOW_BACKGROUND ("\033[43m"),
BLUE_BACKGROUND ("\033[44m"),
MAGENTA_BACKGROUND("\033[45m"),
CYAN_BACKGROUND ("\033[46m"),
WHITE_BACKGROUND ("\033[47m"),
// High Intensity
BLACK_BRIGHT ("\033[0;90m"),
RED_BRIGHT ("\033[0;91m"),
GREEN_BRIGHT ("\033[0;92m"),
YELLOW_BRIGHT ("\033[0;93m"),
BLUE_BRIGHT ("\033[0;94m"),
MAGENTA_BRIGHT("\033[0;95m"),
CYAN_BRIGHT ("\033[0;96m"),
WHITE_BRIGHT ("\033[0;97m"),
// Bold High Intensity
BLACK_BOLD_BRIGHT ("\033[1;90m"),
RED_BOLD_BRIGHT ("\033[1;91m"),
GREEN_BOLD_BRIGHT ("\033[1;92m"),
YELLOW_BOLD_BRIGHT ("\033[1;93m"),
BLUE_BOLD_BRIGHT ("\033[1;94m"),
MAGENTA_BOLD_BRIGHT("\033[1;95m"),
CYAN_BOLD_BRIGHT ("\033[1;96m"),
WHITE_BOLD_BRIGHT ("\033[1;97m"),
// High Intensity backgrounds
BLACK_BACKGROUND_BRIGHT ("\033[0;100m"),
RED_BACKGROUND_BRIGHT ("\033[0;101m"),
GREEN_BACKGROUND_BRIGHT ("\033[0;102m"),
YELLOW_BACKGROUND_BRIGHT ("\033[0;103m"),
BLUE_BACKGROUND_BRIGHT ("\033[0;104m"),
MAGENTA_BACKGROUND_BRIGHT("\033[0;105m"),
CYAN_BACKGROUND_BRIGHT ("\033[0;106m"),
WHITE_BACKGROUND_BRIGHT ("\033[0;107m");
private final String code;
Color(String code) { this.code = code; }
@Override public String toString() { return code; }
}
}
Just dump this code into Logcat.java
and compile using:
javac Logcat.java
And run inside the Android Studio's embedded terminal:
java Logcat <your.package.name>
For example:
java Logcat com.nomone.vr_desktop
The result looks like this:
It's highly customizable, I've separated most of the options in the first section of the app, so you can tweak the colors and formatting easily. If the adb
tool is not in your PATH environment variable, just set its full path in the ADB_FILE_PATH
variable (in the code) before compiling.
When the application is running, you can type the following shortcuts:
c
to clear the screen and local buffer.v
, i
, d
, w
, e
to change the logcat level.q
to quit gracefully. Ctrl+c works too.Unfortunately, you have to press enter after pressing these keys. Seems like Java doesn't allow single character input from console without writing system specific code. Sorry!
I hope this solves your problem :)
Upvotes: 8
Reputation: 1109
For Windows user:
Use this script tool. Make sure you have already set the ADB env for the system. Android Logcat script
com.example.abc
with your package idp/s: Let's star my repo if this answer is helpful. Thanks!
Upvotes: 0
Reputation: 2465
In Android 3.6.1 I had to:
Upvotes: 5
Reputation: 1311
In addition to all great answers: make sure that you import right BuildConfig
if you use it. I'm using BuildConfig.DEBUG
, so one day my IDE automatically imported the wrong class
import com.google.firebase.BuildConfig;
or it may be
import com.adjust.sdk.BuildConfig;
After changing import to the right one everything was fine:
import com.yourapp.BuildConfig;
Upvotes: 0
Reputation: 471
Step 1: Connect Your Phone with Android Developer option On and USB Debug On.
Step 2: Go TO View > Tools Window > Logcat
Step 3: Before Run Project Make Sure Your Phone Connect Android Studio. Then run application
Note: If You Can not Show Logcat Just Restart Android Studio : File > Invalid Caches/ restart
Upvotes: 4
Reputation: 413
You may put some text in the search and filter out the Logcat result.
That was the reason for my problem :)
Upvotes: 0
Reputation:
I checked the answer and only found my mistake accidentally while checking my logcat. Make sure the box on the right says "Show only selected application". Mine was showing "Firebase", so it showed me messages from Firebase.
Upvotes: 3
Reputation: 616
Rebooting the phone I was testing fixed the issue.
I used an old LG4 with Android 6.
I tried unplugging and plugging again, restarting Android Studio, restarting the logcat, invalidating caches - Nothing worked.
Upvotes: 1
Reputation: 308
In my case I was sending empty tag i.e
Log.d("","My Log");
Instead send a tag name
Log.d("Class name","My Log");
Hope it helps someone
Upvotes: 1
Reputation: 25
Well I've tried all of the other answers and nothing is working for poor logcat. My issue with logcat is that it never worked to begin with. From the time I installed Android studio and finally was able to connect a device to adb it never gave me output. It's probably caused by my borked 32 bit Windows 7 setup though... So I wrote a batch script to run through the terminal to run apps with logcat.
adb shell am start -n "com.package.name/com.package.name.Activity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
adb shell pidof com.package.name > pid
for /f %%i in (pid) do (set pid=%%i)
echo %pid%
adb logcat *:V --pid=%pid%
ENDLOCAL
Put this with corrected directory paths and package names into a logcat.bat(or whatever.bat) file.
place the file in your AndroidStudioProjects/package_name/ folder then you can run
C:\User\me\AndroidStudioProjects\package_name>logcat(or whatever)
in the terminal.
Note that you can change what the logcat displays by changing
*:V
In the adb logcat command. (example *:E shows only (E)rror tags).
I hope this was helpful to someone else.
Upvotes: 0
Reputation: 1978
Run this command in terminal. It will start working again.
adb kill-server && adb start-server
Upvotes: 33
Reputation: 487
Make sure you have Logger buffer sizes propper value in your emulator developer menu option.
Upvotes: 14
Reputation: 6132
It's weird to still encounter this problem even on a recent version of Android Studio. I read through the long list of solutions but they did not work for me. The accepted answer worked on an earlier version of Android Studio ( I guess it was v2.3)
I did the following to get Logcat working again:
I expected resetting logcat should ideally give me the same effect but it didn't. Manually toggling filter was the only thing that worked.
This is on Android Studio 3.0.1 (stable) (I can't update it before finishing the current project) The issue occurred when I started Android studio in the morning to continue the work I left at night. I hope the devs will look into this. It was painstaking to try over 15 solutions from stackoverflow and still see no result. It's even irritating to reveal another solution for future victims of this issue.
Upvotes: 7
Reputation: 2380
For me, the problem was that the device was connected in the Charge only
mode.
Changing the mode to Media device (MTP)
(or Transfer files
in some devices) solved the problem.
Upvotes: 4
Reputation: 20368
You need to press Alt+6 twice to restart the logcat window. That way it'll show the log outputs.
The problem mainly happens in debug mode.
Upvotes: 68
Reputation: 91
That occasionally occurs to me while using emulator. I just plug in a device and run the app. The Logcat gets back to work and so it does when I get back to the emulator. I guess that just switching two devices and/or emulators does the trick as well.
Upvotes: 2
Reputation: 84
I tried the suggestions above. However, none of them worked. I then did the following which surprisingly worked:
adb tcpip 5555
and adb connect <device ip>
adb kill-server
The LogCat then showed the logs. Even though the logs were available at step 2, the following steps resolved the issue for me when connecting via USB.
Upvotes: 1
Reputation: 439
Upvotes: 2
Reputation: 193
In my case, I removed "image" from the little dropdown on the right. It showed up just fine after that. That's because it will be searching the log for the keyword in that searchbox, so if it doesn't find any matches, it returns blank
Upvotes: 7