Eclipse Logcat Debugging

How to open LogCat in Eclipse (for Android Debug)

LogCat is located here:

Window > Show View > Other > Android > LogCat

I hope this helps.

Eclipse logcat debugging

After you see

FATAL EXCEPTION: main

you will see the problem, here a NPE

09-23 11:27:55.968: E/AndroidRuntime(807): java.lang.NullPointerException

then you find the first line that references your app. Here it is the following line

at com.uniqueapps.runner.Start.onClick(Start.java:49)

This says that in Start.java something is null in onClick() at line 49. So you go to that line and see what could be null...like a variable that tries to access a method such as setText(), getText(), or any Android or user defined method. Sometimes it is simple why it is null and sometimes you have to trace back further to see what makes it null.

Edit

If a variable is null it is because it hasn't been initialized properly, or at all. So maybe you have a variable TextView tv; but you never gave it a value by doing something like

 tv = (TextView) findViewById(R.id.myTV);

if you try to do something like tv.setText("Some Text"); you will get a NPE because you didn't initialize it with something like the above line of code. Or maybe you tried to initialize it and used the wrong id like one from a different layout. This will return null and create a NPE in the same way. This can be on any variable that you try to call a method on.

Why doesn't logcat show anything in my Android?

Maybe you have Mylyn installed?

http://code.google.com/p/android/issues/detail?id=1808

How to enable LogCat/Console in Eclipse for Android?

In Eclipse, Goto Window-> Show View -> Other -> Android-> Logcat.

Logcat is nothing but a console of your Emulator or Device.

System.out.println does not work in Android. So you have to handle every thing in Logcat. More Info Look out this Documentation.

Edit 1: System.out.println is working on Logcat. If you use that the Tag will be like System.out and Message will be your message.

What is LogCat in Eclipse?

This is a nice and quick way to exchange information from the application on your device and the development computer.

To use Logcat, first import android.util.Log into your project. Now you can call the static class Log from your project to start logging. As you can see below, Logcat has different levels of logging. When debugging, we’ll just use Debug (D) to log the progress. Of course, when you want to log an actual error, you will use Error (E).

V — Verbose (lowest priority)
D — Debug
I — Info
W — Warning
E — Error
F — Fatal
S — Silent (highest priority, on which nothing is ever printed)

For more detail, see Debugging in Android using Eclipse.

Eclipse - Limit logcat output to debug relevent logs

Filter the Logcat with "app:com.yourdomain.appname". I've also added a filter that gets rid of more items using a not operator:

tag:^((?!CoreMetrics|InputEventConsistency|memalloc|Adreno200-EGLSUB|Resources|global|TaggingRequest|Facade[B|U]|dalvik|skia|KeyCharacterMap|BackStackEntry|FragmentManager|ServiceRunnable|ServiceLocator|BaseHttpRequest|szipinf|APACHE).)*$

You'll need to edit the list specifically for the items you're seeing, but it's a great way to reduce the static.

Eclipse logcat no logs from Pixel XL, No Debugging, Phone not recognized

It's not about Eclipse version, i used Eclipse Juno, Mars and now using Oxygen. There is no logcat support for Android 7.0 and above in Eclipse. You should use a device with Android below 7.0 like i do or migrate your project to Android Studio.

I had to migrate to Android Studio not only because support for Eclipse is diminishing everyday. You can't use new libraries, such as FusedLocationProvider. You need to get used to working with Android Studio even if you don't like it. Frankly, i don't like Android Studio very much but it's the way it's supposed to be.

Eclipse also does not support MultiDexing which is essential for big projects.

How can I see the error log (logcat) for Android in Eclipse?

Sometimes the device gets "out of sync" with eclipse and logcat doesn't show any messages, as you've discovered.

To fix this, try a) going to DDMS and selecting your device; b) closing the logcat tab and creating a new one; c) disconnecting your device and reconnecting it; d) exiting eclipse and restarting it; e) rebooting your device; or f) rebooting your computer, in that order. Usually the problem is fixed by the time you've done a).

Automatically clearing LogCat on each Eclipse Debug/Run?

If you're not locked to Eclipse because of some strong reasons, you can try IntelliJ IDEA as IDE. Here is option for run configuration for clear log on app run. Unfortunately, following http://youtrack.jetbrains.com/issue/IDEA-80976 it is broken right now, but I think it'll be fixed in near future.