Category: Eclipse

Configuring Hidden, Invisible, or Whitespace Characters in The Eclipse Text Editor

Posted on by rchapin

The newer (I am currently using Mars, 4.5.0) versions of Eclipse provide very good tools for configuring the visibility of whitespace characters in code.

To customize your settings go to Window -> Preferences -> General -> Editors -> Text Editors.

On that page there will be checkbox option next to “Show whitespace characters (configure visibility).

Clicking on the ‘configure visibility’ link will allow you to choose what is shown and the opacity of the whitespace characters, which is a really nice touch.

Using the Eclipse Memory Analyzer (MAT) Remotely on Large Heap Dumps

Posted on by rchapin

Sometime your java applilcation will fail and generate an enormous heap dump.  One that may be too large to be able to transfer to your local machine and to analyze for lack of RAM, time or both.

One solution is to install the MAT tool on the remote server and generate an HTML output of the analysis to download and view locally.  This saves the headache of attempting to get X Windows installed on the remote machine and get all of the ssh tunneling sorted out (which is of course an option as well).

First, download and install the stand-alone Eclipse RCP Application.  Then transfer to your server and unpack.  Then determine how large the heap dump is and, if necessary, modify the MemoryAnalyzer.ini file to instantiate a JVM with enough RAM for your heap dump.

In this example, I have an 11GB heap dump and have modified the last two lines (adding -Xms)

-startup
plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.gtk.linux.x86_64_1.1.300.v20150602-1417
-vmargs
-Xmx16g
-Xms16g

Do an initial run to parse the heap dump.  This will generate intermediary data that can be used by subsequent runs to make future analysis faster.

./ParseHeapDump.sh /path/to/heap-dump

After that completes, you can run any of a number of different analysis on the data.  The following is an illustration of how to search for memory leak suspects.

./ParseHeapDump.sh /path/to/heap-dump org.eclipse.mat.api:suspects

Additional reports:

org.eclipse.mat.api:suspects
org.eclipse.mat.api:overview
org.eclipse.mat.api:top_components

To give creadit where it is due, this is basically a copy of a post by Ashwin Jayaprakash, but I wanted to capture it here as well.

Debugging MapReduce MRv2 Code in Eclipse

Posted on by rchapin

Following is how to set-up your environment to be able to set breakpoints, step-through, and debug your MapReduce code in Eclipse.

All of the this was done on a machine running Linux, but should work just fine for any *nix machine, and perhaps Windows running Cygwin (assuming that you can get Hadoop and its naitive libraries compiled under Windows).

This also assumes that you are building your project with maven.

Install a pseudo-distributed hadooop cluster on your development box.  (Yes, this calls for another article on exactly how to do that which I will do shortly and link to from here).

Add the following environment variables to .bash_profile to ensure that they will be applied to any login shells (make sure to check the location of the directories for your installed hadoop distribution):

export LD_LIBRARY_PATH=/usr/lib/hadoop/lib/native
export HADOOP_HOME=/usr/lib/hadoop

Make sure to include the following dependencies in your pom:

  • hadoop-mapreduce-client-core
  • hadoop-common
  • hadoop-hdfs
  • hadoop-client

After you import your maven project into Eclipse update the Build Path to include the correct path to the Native library shared objects:

  1. Right-click on your project and select ‘Build Path -> Configure Build Path:
  2. Click on ‘Libraries’ tab:
  3. Click the drop-down arrow for the ‘Maven Dependencies’
  4. Click on the drop-down arrow on the ‘hadoop-common’.jar
  5. Select the ‘Native library location’ entry, and click ‘Edit’
  6. Browse to the path of the native directory, in my case it was /usr/lib/hadoop/lib/native.
  7. Click ‘OK’
  8. Click ‘OK’ to close the build path dialogue

Create a run configuration for the Main class in your project:

Make sure that you do not add the /etc/hadoop/conf* dir to the class path.

Add any commandline arguments for input and output directories to the ‘Program arguments’ section of the run configuration, that points to your LOCAL file system and not HDFS.

Afterwhich, you should be able to run your M/R code and debug it through Eclipse.

Configuring Eclipse to Replace Tabs with Spaces for Indentation

Posted on by rchapin

Following are two basic settings (I believe that there are other language specific, C++ for instance, settings as well).

 For Java:

Window->Preferences->Java->Code Style->Formatter->
Click on ‘New’ to create a new profile and select the profile that you want to copy
Then click ‘Edit’ and select ‘Spaces Only’ from the ‘Tab Policy’ dropdown.

You can further set the indentation and tab size.

For default text editor:

Window->Preferences->General->Editors->Text Editors->Insert spaces for tabs

Eclipse Android Development Error executing aapt: Cannot run program “/path/to/aapt”: error=2, No such file or directory: error=2, No such file or directory

Posted on by rchapin

Even though the ADT bundle provides a 64 bit version, the system requirements indicate that “64-bit distributions must be capable of running 32-bit applications.”  I failed to see that when installing it under Fedora Core 20 and was getting the following error from Eclipse:

Error executing aapt: Cannot run program "/home/rchapin/sdks/adt-bundle-linux-x86_64-20131030/sdk/build-tools/android-4.4/aapt": error=2, No such file or directory: error=2, No such file or directory  android_sdk    line 1   Android ADT Problem

I checked to see if the file was there.  Yep.  I checked to see if was executable.  Yep.

It was only after finding a blog post about it and doing a file command on it that I noticed that it was a 32 bit executable:

file adt-bundle-linux-x86_64-20131030/sdk/build-tools/android-4.4/aapt 
adt-bundle-linux-x86_64-20131030/sdk/build-tools/android-4.4/aapt: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.8, not stripped

All I had to do was install the 32 bit libraries that the binaries are linked against:

yum install glibc.i686 zlib.i686 libstdc++.i686 ncurses-libs.i686 libgcc.i686

Once installed, the error should disappear from Eclipse as it tries to invoke the binaries and do a regular build and/or restarting or cleaning the project should clear the errors.

Setting up Android in Eclipse, Unable to resolve target ‘android-18’

Posted on by rchapin

When setting up Eclipse for Android development, after you have installed the Develeper Tools and NDK Plugins and linked to the ADT-bundle and then imported your project (see othere posts related by searching for ‘android’) I got the following error:

[2014-03-24 14:14:53 - android_sdk] Unable to resolve target 'android-18'

I went and checked to make sure that the Platform.MinPlatformToolsRev property in the ~/path/to/adt-bundle-linux-x86_64-20131030/sdk/tools/source.properties matched that of my project.properties file.

They were both 18.  Eh?  Why the error?

So, in Eclipse, I went to the Window > Android SDK Manager and looked at the version of the Android SDK Platform that was installed.  It was:

Android 4.4.2 (API 19) and the checkbox next to SDK Platform under that sub-heading was checked.

So, I went back to my project.properties and updated the target property to:

target=android-19

which eliminated that error.

Invalid Project Description, project path overlaps the location of another project with the same name When Importing Existing Android Project in Eclipse

Posted on by rchapin

I’ve got a new install of Eclipse and am setting up to do some Android development.

After getting the Develeper Tools and NDK Plugins installed and linking to the ADT-bundle that I downloaded, I was getting an error when attempting to import the existing project by going to File > Import > Android > Existing Android Code Into Workspace.

The error was:

Invalid project description /some/path/to/project/dir_name overlaps the location of another project: dir_name

After a few searches and a couple of tries, using the File > Import > General > Existing Projects into Workspace seemed to work just fine.

Eclipse Crashing with SIGSEGV, Problematic Frame libgdk and/or libsoup Problem Solved

Posted on by rchapin

I’m setting up a new workstation under Fedora Core 20 and getting my dev environment set up.

I had copied over my /opt dir from my old machine which included an older version of Eclipse (3.8.2) that I had been using.  That version wasn’t behaving very well and I decided to go with the latest and greatest stable version (Kepler, 4.3.1).

Unfortunately, Kepler was dumping core with the following error:

 A fatal error has been detected by the Java Runtime Environment:

  SIGSEGV (0xb) at pc=0x00000030f703d09a, pid=2450, tid=139984564643584

 JRE version: Java(TM) SE Runtime Environment (7.0_51-b13) (build 1.7.0_51-b13)
 Java VM: Java HotSpot(TM) 64-Bit Server VM (24.51-b03 mixed mode linux-amd64 compressed oops)
 Problematic frame:
 C  [libgdk-x11-2.0.so.0+0x3d09a]  g_param_spec_object+0x3d09a

 Core dump written. Default location: /home/rchapin/core or core.2450

I realized that I had installed Acrobat Reader, and since I’m on a 64 bit architecture that included all of the i686 rpms and compatibility libs.  I thought that that for some reason there might be some confusion between which version of libgdk that was being used.  That wasn’t it.  I tried a different JDK (Oracle vs OpenJDK), nope, that wasn’t it either.

Eventually, I tried deleting (actually moving aside) the .eclipse/ dir in my home dir and deleting all of the .classpath, .settings, and .project files and dirs in my workspace and then re-installing my Eclipse plugins for Kepler.

Worked like a charm.

What I think was happening was that some of the plugins for different versions of Eclipse were being pulled in at runtime and causing the Kepler binary to crash.

Setting Up Android SDK and Plugin in an Existing Install of Eclipse

Posted on by rchapin

To set up an existing install of Eclipse to do some Android development do the following:

  • Go to http://developer.android.com/sdk/index.html and look for and download the ADT bundle for your OS (in my case I was using Fedora Core 18 at the time)
  • Unpack it as the user that is going to be running Eclipse and/or after you unpack it make sure that your user has read/write/execute permissons for the files in this directory (obviously, you don’t need execute permssion for non executables).  To make things easy, I just created an ~/sdks directory and unpacked it in there.
  • Fire up eclipse and go to Help/New Software.
  • Add the following repository: https://dl-ssl.google.com/android/eclipse/
  • Check off both the Developer Tools and NDK Plugins.
  • After those plugins install go to Window/Preferences/Android, and click the ‘Browse’ button next to ‘SDK Location:’, selecting the /path-to/adt-bundle-linux-x86_64-20130917/sdk.  When setting this up you might get a dialogue box that indicates that the version of the Android SDK Tools and/or Android SDK Platform Tools is not compatible with the version of the adt-bundle you are attempting to use.  In my case, I was prompted to update it via the Android SDK Manager and was able to download an updated version.

If you have an existing project that you are working with you might have to update the project.properties to update the sdk level number.

You might see an error like:

Unable to resolve target ‘android-17’ until the SDK is loaded

If so, update the ‘target=android-17’ property in the project.properties file to match the value of ‘Platform.MinPlatformToolsRev’ in the /path-to/adt-bundle-linux-x86_64-20130917/sdk/tools/source.properties file.

In my case, I updated the project.properties to:

# Project target.
target=android-18

Getting the value ’18’ from the source.properties:

Platform.MinPlatformToolsRev=18

© 2005 Ryan Chapin