There was a program that I used that made runnable .jar files.. All the ones I'm finding now are ones that make .exe files.. I remember it also has the option to make the file a .sh script as well. Anyone knows its name? I've been searching for hours with no avail :/
The command line
java -jar file.jar
Will run your jar file if it has a Main-Class defined as explained here.
You can use that command in a shell script.
You can create a runnable jar using NetBeans IDE or Eclipse IDE by just providing the main class to run. Rest of the things it will take automatically. That class must be having a main() method in it. Then you can run that jar file using java -jar yourjarfile.jar
Do you mean actually coding java and then compiling to .jar? If you do try
eclipse code editor
I used eclipse to make minecraft mods. It will work if you want to make .jar programs.
If you want to have a jar that you can execute using the usual syntax ./app.jar (instead of java -jar), here is a post explaining the process: how to create executable jars.
Basically, JAR is a variant of ZIP, which allows random bytes to be pre/appended to the JAR without corrrupting it. This means it is possible to prepend a launcher script at the beginning of the jar to make it "executable".
Here is a simple example of the process:
# Append a basic launcher script to the jar
cat \
<(echo '#!/bin/sh')\
<(echo 'exec java -jar $0 "$#"')\
<(echo 'exit 0')\
original.jar > executable.jar
# Make the new jar executable
chmod +x executable.jar
With this, you can now run ./executable.jar instead of java -jar original.jar. This works on all unix like systems including Linux, MacOS, Cygwin, and Windows Linux subsystem.
Related
If I extract a Jar file into a directory, what's the correct java command to run it as if it was the jar?
Meaning, what would be the equivalent command to java -jar myProgram.jar except not using the jar itself?
I've tried stuff like java -cp ".;META-INF\lib\*" JarMain but it seems like there's still something missing there.
Do you mean that add a jar to classpath but do not run it? If so, java -cp myProgram.jar;ohterjar/libdir JarMain. If you use linux/mac,replace ; to :.
If you run jar file directly (without extracting), you can use command: java -jar jarfilename. jar
If you extract jar file into separated files, you can run .class file only. Use the command java classfilename.
You need to set path environment to java/bin directory before running above commands, or just change directory to it.
In CMD I compile project with including libraries
java -cp app.jar;libs/*;. com.app.Main
and it works, but I want create BATCH script, which do exactly the same. I create test.bat and put code like below:
#ECHO off
java -cp app.jar;libs/*;. com.app.Main
PAUSE
But when I run the test.bat the CMD was shown and there is information "Error: Could not find or load main class com.app.Main".
BATCH script is located at the same folder as app.jar and libs folder.
What is wrong with this batch script?
Probably the characters on the compile line are significant to the batch interpreter; try putting the classpath in double quotes.
After Java 6, Classpaths could be built by using wildcard characters.
You can create a directory named classpath and put your JARs inside it. Then you can create your .bat file like this:
#ECHO off
java -cp .;classpath/* com.app.Main
pause
You should have a structure like this:
com
`---app
`---Main.java
classpath
`---your-crital-code-1.0.jar
compile.bat
I see that a lot of people are asking this question on StackOverflow, so here is a little tip for you guys.
I usually avoid using the cd command, as it may create some hassle. In windows, you can Shift + Right Click to open a command window in a particular directory.
I always prefer relative paths over absolutes, so that I don't get into hassle of managing long paths.
Here is a little program that deals with this kind of problem. You can always refer to and contribute to it so that we can make good examples for Java beginners :)
I am a bit confused about the process to create a .bat file of a java application. I have exported the executable jar using IDE say Application.jar in C: directory. Then I have written two lines in a .txt file as stated below and saved it as .bat file in the same directory where i have my application.jar. But on double click of the .bat file, the application is not getting executed.
.BAT file code
javac Application.java
java -cp . Application
Note: I have also set the JRE and JDK path in my environment variables till bin path in My Computer properties. But it is not working. Can someone suggest me how can I fix this, because I want to execute my code by doubleclickng on a .bat file. It will be nice if someone can provide me every step I need to follow to accomplish this as I havent ever done this before.
Thanks ,
The first line in your batch file is attempting to compile your program !?
The second line is attempting to run the Application.class file.
What you want if you have produced an executable jar file is:
java -jar Application.jar
But you don't really need the batch file at all. If you double click on the jar file and it runs your program then you can just create a shortcut to it.
Your .bat is just fine. When you double click it might be executing and then closes. This is because your program might not have any UI and it isnt waiting for any input. To verify this take a command prompt and then execute your bat file via that.
In other case I assume that you have a java class called Application and you need to run this via a batch file. In that case if the class have a main method then you just need one line in .bat file
java -cp <the path to class file> Application
So you might be using a javac just to take advantage of class path as current directory. So when you say
javac Application.java
java -cp . Application
It compiles the class to current folder and set that as class path and then execute. This is absolutely file as long as the Application.java doesnt have any third party dependency. But in this case again you need not set -cp to . (current directory will be taken as classpath automatically unless otherwise specificed). So below will also work fine.
javac Application.java
java Application
I support Jurgen reply. If you have an executable jar file and a jre in path then double clicking it will run the application. The META-INF folder inside the jar will have a MANIFEST.MF file which uses a property called Main-Class: to specify the main executing class. And on double clicking this class gets executed. However its only useful if you have a UI. Else it'll also have no effect.
In all these context the Application.jar you mentioned is irrelevant. If that is a third party jar that you need to run the you should include that in -cp argument.
I think I have seen this done, but am not sure where. What I want to do is to create a bat file I can package with my class files when sending to a friend to show them progress/ask advice on non programming matters. My friend is not very handy when it comes to code and doesn't like changing computer settings. Just using java myClass as a command line won't work here because although my friend does have java installed, he has not set his windows environment variables so his command prompt knows where to find java.
What kind of line would I need to add to my batch file to make it so it can compensate for problems like this?
Create a manifest file (manifest.txt):
Main-Class: com.mycompany.myapp.MyMainClass
Package your app as a jar:
jar cfm myjarfile.jar manifest.txt *.class
Create a batch file:
start myjarfile.jar
If it is about sharing and running a single java file without jar dependencies. And you are only worried about the java runtime environment setup, then you can use online java code compilers and executors. Here is one:
http://javalaunch.com/JavaLaunch.jsp
You can google for more!
Use an IDE, NetBeans or eclipse and package your files as a Jar file.. that can be executed directly and you do not need to worry about dependencies, other classes or libraries.
How can I run a jar that needs several jars to work?
Let me explain, I have for example a project with a jar "Main.jar" but to run this Main.jar I need jdom.jar(for xml file), jGit.jar...
Assume we need more than two jars. How can I run my Main.jar?
By including the needed jar files in the classpath. Something like:
java -cp "Main.jar;jdom.jar;jdom.jar" MainClass
If you are under Windows and would like to execute the Main.jar with a double click, you will need to create a .bat file and use that one instead to run your program. The content of the .bat file will have the above command.
Under Unix/Linux you will create a shell file with the similar content.
Note that the -cp argument values will need to contain all the jars that your Main.jar is depended on.
Run the jar with main class and add all other jars to classpath.
java -cp yourJars yourClass
see this post for more info. See this java tutorial