HOWTO: Set gedit to compile and run Java source code

[WiseElben]

Introduction

I use gedit with the terminal panel plugin when I'm programming small Java programs. This becomes a hassle sometimes, so I created a simple gedit "Tool" that would compile and run Java source files. Some people would prefer using just the plain terminal or a complicated IDE, but this is especially useful for students who just needs a basic yet easy-to-use interface to learn Java on.

Instructions

First, open gedit and go to Tools=>External Tools. Create a new tool and label it something like "Java Compile." Set an accelerator if you want to.

Then inside the Command, insert this:

#Compiles the current open Java source file.
echo "Compiling: " $GEDIT_CURRENT_DOCUMENT_PATH
echo '--------------------'
javac $GEDIT_CURRENT_DOCUMENT_PATH

The second part (the tool to run the class) is a bit more difficult because gedit runs the script using /bin/sh, which doesn't support the necessary regex command. Because of this, we have to make a separate script file.

Since gedit is already open, make a new file and copy in:

#!/bin/bash

#To be used with gedit Tools to run a compiled Java source file.
[[ $2 =~ "\w+" ]]
cd $1
java $BASH_REMATCH

Save as java_run under a .gedit folder in your home folder. You might need to create the .gedit folder.

Now, create another Tool. Call this one "Java Run" and copy the following under Command:

#Runs a compiled Java source file.
echo "Running: " $GEDIT_CURRENT_DOCUMENT_PATH
echo '--------------------'
bash ~/.gedit/java_run $GEDIT_CURRENT_DOCUMENT_DIR $GEDIT_CURRENT_DOCUMENT_NAME

You're done! You might want to create a sample program to test this.

Final Thoughts

This feature in gedit is a bit buggy, so don't be surprised if your custom Tools suddenly vanish or jump around; this happened to me a couple of times when I was figuring this out.

[Rhenthalin]

This little device sounds absolutley wonderful for my purposes however, I do not seem to have the tool=>external tools feature. Is this a Feisty Fawn feature or is my gedit just very noobly.

[zobdos]

actually, there is a much easier way to run the compiled classfile...

code:

java ${GEDIT_CURRENT_DOCUMENT_NAME%\.*}

thats it. lol.

[thomas_vergote]

Hi,

I'm a beginning java programmer (in two days I have my exam) and I use eclipse by default as editor and compiler.
However I want to compile and run my java programs also in gedit, because I love the simplicity of gedit and for a fast check, gedit is excellent...
So I found this thread and I am able to compile without any problem, however, running the program just doesn't seem to work out!
This is what I get:

Running: /home/thomas/workspace/examenvoorbereiding/src/TestSorteren.java
--------------------
Usage: java [-options] class [args...]
(to execute a class)
or java [-options] -jar jarfile [args...]
(to execute a jar file)

where options include:
-client to select the "client" VM
-server to select the "server" VM
-hotspot is a synonym for the "client" VM [deprecated]
The default VM is client.

-cp <class search path of directories and zip/jar files>
-classpath <class search path of directories and zip/jar files>
A : separated list of directories, JAR archives,
and ZIP archives to search for class files.
-D<name>=<value>
set a system property
-verbose[:class|gc|jni]
enable verbose output
-version print product version and exit
-version:<value>
require the specified version to run
-showversion print product version and continue
-jre-restrict-search | -jre-no-restrict-search
include/exclude user private JREs in the version search
-? -help print this help message
-X print help on non-standard options
-ea[:<packagename>...|:<classname>]
-enableassertions[:<packagename>...|:<classname>]
enable assertions
-da[:<packagename>...|:<classname>]
-disableassertions[:<packagename>...|:<classname>]
disable assertions
-esa | -enablesystemassertions
enable system assertions
-dsa | -disablesystemassertions
disable system assertions
Closed: 256

I hope someone can help me get this fixed, I must be doing something wrong and I suppose its something small...

Thanks!

[phunkizm]

thomas,

I had the same problem, but then I tried zobdos' simpler version and it works great. Give it a try.

[DaymItzJack]

How can I get this to save the current file before trying to compile? thanks.

[danielarseno]

The following script will compile and, if compilation is successful, run the class.

#!/bin/sh
cd $GEDIT_CURRENT_DOCUMENT_DIR
if javac $GEDIT_CURRENT_DOCUMENT_NAME;
then
java ${GEDIT_CURRENT_DOCUMENT_NAME%\.java}
else
echo "Failed to compile"
fi

[officialhopsof]

Here is a script for compiling and running a java program. I ran into the problem of having to set the class path, my script does this for you. Also, you have to have python installed for this to work.

#!/bin/sh

cd $GEDIT_CURRENT_DOCUMENT_DIR

python -c "
import os

arg = '$GEDIT_CURRENT_DOCUMENT_DIR/$GEDIT_CURRENT_DOCUMENT_NAME'
package = ''
data = open(arg, 'r').readlines()

for i in range(len(data)):
	temp = data[i].strip()
	if temp[0:7] == 'package':
		package = temp[8:len(temp)-1]

if package != '':
	for i in range(package.count('.') + 2):
		arg = arg[0:arg.rfind('/')]
	
	os.system('javac -cp ' + arg + ' ' + '$GEDIT_CURRENT_DOCUMENT_DIR/$GEDIT_CURRENT_DOCUMENT_NAME')
	os.system('java -classpath ' + arg + ' ' + package + '.' + '${GEDIT_CURRENT_DOCUMENT_NAME%.java}')
else:
	os.system('javac $GEDIT_CURRENT_DOCUMENT_NAME')
	os.system('java ${GEDIT_CURRENT_DOCUMENT_NAME%.java}')
"

it works for my purposes. There is just one case that i can see that this wont work on, if you have something like this. my script will see the other package statement there and think it is the one we need.

/*
this is the old package
package something.another.and.another;
*/
package something.else.in.another.place;

that being the case, the following would work fine

//this is the old package
//package something.another.and.another;

package something.else.in.another.place;

because of the leading "//"

enjoy

[D.Sync]

I had several issues here:

1) The following error occured when I import java.util.* to called the Scanner.

Exception in thread "main" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:855)
at java.util.Scanner.next(Scanner.java:1478)
at java.util.Scanner.nextInt(Scanner.java:2108)
at java.util.Scanner.nextInt(Scanner.java:2067)
at Q8.main(Q8.java:32)

Exited: 256

2) If the .java file is located on another drive, eg: /media/WINXP/Documents and Settings/UserName/My Documents/My Java, the following error will occured. But still, it will still run the .class file.

cd: 10: can't cd to /media/WINXP/Documents

[KdotJ]

This is fantastic! This will save me some time!
thanks