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.
Related
Currently, there is bat file that calls the main class in a jar file. Now I want to run it using eclipse. How do I configure the eclipse to run it?
I have tried the Run > External tools > External tools configuration. But I don't know what to type in...
#echo off
set MODULE2_HOME=%~dp0..
set JAVA_HOME=C:/Program Files/Java/jdk1.6.0_71
set CLASSPATH="%MODULE2_HOME%/classes;%MODULE2_HOME%/lib/*;%MODULE2_HOME%/lib/oracle/*;%MODULE2_HOME%/lib/aspose/*;%MODULE_HOME%/aspose/*"
set SETUP_PROPERTIES="%MODULE2_HOME%\conf\setup.properties"
set PATH=%JAVA_HOME%\bin;%PATH%
java -cp %CLASSPATH% -Dsetup.properties=%SETUP_PROPERTIES% com.module.fast.main.Module2Main %*
How do I configure eclipse to run exactly like this command?
Since it is a batch file which will run in Windows. You can go to the command prompt and run the batch file using .bat. You do not need Eclipse. You can run the java class in eclipse. Still if you want to run, you can check the following screenshot.
While configuring, make sure to give the complete path of batch file. If the bat file needs extra commandline params, you can give the batch file location with space and the command line parameters separated with spaces.
It does not work to run the jar file which contains main class, you have to give the working directory location.
I am trying to schedule up java application using windows scheduler.
I have created bat file where is written: java -jar C:\....(full path)\myJar.jar
Java is using data folder, located right next to jar file, during execution. Everyone has access to the data folder so permission is not the issue as far as I understand.
The way I access to the folder in java is by setting path: "data\\test.csv"
Please note that bat file is located next to jar file and the data folder.
Interesting is that if I run the bat file manually then everything works fine, when I run it from scheduler, error occurs.
I have solved it by adding cd line to bat file. So before execution of jar, directory is changed.
Bat file would look like this:
cd C:(full path to directory)
java -jar myJar.jar
pause
I'm trying to run my Java program using a batch file, I'm able to run it properly. However, when I run the batch file after inserting the code to read a properties file from the Java program, I'm getting the following error.
Can't find bundle for base name app1, locale en_US
Actually i have a conf folder under which I have this properties folder, then I came to know that I need to keep this conf folder in the class path. But I have actually added it as class folder using Eclipse. However, I'm getting the same error. Please let me know what exactly I need to do for running the Java program using batch file. Using Eclipse I'm able to run the properly.
Thanks,
Balaji.
From the comments your batch script:
#echo off
java -Djava.ext.dirs=lib -classpath ./bin com.myapp.app1.demoprogram
pause
Notice how the /conf/ directory is not listed on the classpath. The easiest way to get it there is to just add it to the -classpath argument being passed to the JVM. Something closer to:
#echo off
java -Djava.ext.dirs=lib -classpath ./bin;./conf com.myapp.app1.demoprogram
pause
This is assuming that /conf/ is in the same directory as bin. You might have to do some tweaking to get the setup to work for you application, but the root problem is that while you added the /conf/ folder to the project classpath in eclipse, you need to do the same thing for the batch script so the JVM can find it
Is there a way to pass an external jar file when running a .jar application?
I'm trying to run my jar like this:
java -jar myJar.jar -cp externalJar.jar
The jar file executes fine but I want to look for classes in the external file. I can't include the other classes into my jar, because I want to be able to put any jar file in the same folder as my Jar file and look for classes in there.
The only way to do this right now is by running my app like this:
java -cp myJar.jar;externalJar.jar MainClass
I do not want to explicitly enter the path to my MainClass to run it's main method.
It really seems that the -cp option is completely ignored when you use the -jar option. At least this is what you can read on the manpage of java about the -jar option:
Execute a program encapsulated in a JAR file. The first argument is
the name of a JAR file instead of a startup class name. In order for
this option to work, the manifest of the JAR file must contain a line
of the form Main-Class: classname. Here, classname identifies the
class having the public static void main(String[] args) method that
serves as your application's starting point. See the Jar tool
reference page and the Jar trail of the Java Tutorial for information
about working with Jar files and Jar-file manifests.
When you use this option, the JAR file is the source of all user classes, and other user
class path settings are ignored.
Note that JAR files that can be run with the "java -jar" option can
have their execute permissions set so they can be run without using
"java -jar". Refer to Java Archive (JAR) Files.
I found this in this blogpost here: http://happygiraffe.net/blog/2009/04/30/java-jar-blats-your-classpath/
Did you try adding a specific folder to the classpath during startup and then add your jar file to the folder at later point ?
I've been learning about JAR files and wanted to try and create and run one myself. I carried out the following steps:
Created a project folder with a 'source' subfolder and a 'classes' subfolder
I wrote 2 source files, one with a main method which creates an instance of the other class and runs a simple method in it.
Compiled these to the 'classes' subfolder. I checked to see if they would run. They did
I created a manifest.txt file and filled in the Main-Class: xxxx and hit the return key. I saved this in the sources subfolder
Created a jar file in the classes subfolder by writing
jar -cvmf manifest.txt zzz.jar *.class
Tried to execute the jar file by typing
java -jar zzz.jar
This gives a ClassNotFound exception. If I try to execute the jar by double clicking on it in windows I get an errorbox saying "Could not find the main class xxxx"
I've double checked the spelling of the class inside the manifest file and it's correct.
Possibly important: I have to compile my programs using java -cp . xyz as there is an issue with my classpath. Does this mean that I need to execute jars in a different way as well? I tried
java -cp . -jar zzz.jar
but ended up with the same exception.
Edit: I ended up starting from scratch and now it runs (with the basic -jar zzz.jar command). Frustrating that I don't know what I was doing wrong but glad that it is working!
Shouldn't number 5. be run in the classes subfolder, where all your class files are? And if your classes are in packages, which they should be, you'll likely want to use * instead of *.class..?
To check what your jar file contains you can run:
jar tf zzz.jar
You will probably have to supply the entire path of the .class file you wish to execute after the classpath. ie java -cp xxx.jar classes.mainProgram.class. Where classes is the name of the folder which contains your class files.