How to make a jar file from code? - java

I have some java code written in a text file, now I want to create a jar file to use that file as a library in my android project. So what would be the best way to make a jar file from this point. Please note that I have some code written in a textfile and saved as a .txt. If I rename that file to .java and use this code
jar cf filename.jar file(s)
a jar file is created but when I decompile it in java decompiler it doesnt show the packages and that codes that's why I am unable to use it's methods. What would be the best way to do this? I need help

If you want to use the classes in your library they must be compiled and you have to manually create all the packages subfolders.
So :
1. Make a folder
2. Create each package subfolderds in it (com/foo/bar/xxx)
3. Compile each of your .java files and put them it the correct subfolders
4. Zip your folder and rename it with a .jar extension
But it is hard to do this by code, why don't create it with your IDE ?

Creating a jar File in Windows Command Prompt
Start Command Prompt.
Navigate to the folder that holds your class files:
cd \mywork
Rem -- Set path to include JDK’s bin. For example:
path c:\Program Files\Java\jdk1.5.0_09\bin;%path%
Rem -- Compile your class(es):
javac *.java
Rem -- Create a manifest file:
echo Main-Class: DanceStudio >manifest.txt
Rem -- Create a jar file:
jar cvfm DanceStudio.jar manifest.txt *.class
Rem -- Test your jar file by trying to execute it
Rem -- This will not apply for a library JAR file without any main
java -jar DanceStudio.jar

Related

Combining .java files and exporting them as an executable jar from java code

I want to know how to export a jar file from within java code. Look at the following situation:
I have some .java files including one main class. I want to know how to pack those files and convert them to an executable jar file. I don't want to do this the traditional way by exporting the project to a jar file using eclipse built in functionality (I know how to do that). I want to know how to export the .java files and the required libraries to a jar file using java code.
Here is my ideal result: I run my own jar exporting program and it asks me to select some files. When I do select and hit 'export', it packs those files in an executable jar file. Thanks in advance and peace out.
Maybe you could try running cmd commands for creating JAR file using JAVA code.
You can create jar File in Command Prompt following these steps:
- Start Command Prompt.
- Navigate to the folder that holds your class files:
C:\>cd \mywork
- Set path to include JDK’s bin. For example:
C:\mywork> path c:\Program Files\Java\jdk1.7.0_25\bin;%path%
- Compile your class(es):
C:\mywork> javac *.java
- Create a manifest file
manifest.txt with, for example, this content:
Manifest-Version: 1.0
Created-By: 1.8.0_171 (Oracle Corporation) #your jdk version
Main-Class: mainPackage.MainClass
- Create the jar file:
C:\mywork> jar cvfm Craps.jar manifest.txt *.class
To see how can we run these commands within JAVA code, follow this link:
Run cmd commands through Java

Running *.jar file with some dependencies to other *.jar files using cmd

I have program in Java in path: C:\...\MyProgram.
This program have some dependencies to others *.jar files. I would run it using cmd. So what I do:
in cmd I write cd C:\...\MyProgram\bin and then java -cp C:\...\MyProgram\*;. main.Main. It is working. But now I exported MyProgram to jar file. Could you tell me how can I run this now? So I have file MyProgram.jar with these same dependencies. How run it by using cmd?
Folders and archive files
When classes are stored in a directory (folder), like /java/MyClasses/utility/myapp, then the class path entry points to the directory that contains the first element of the package name. (in this case, /java/MyClasses, since the package name is utility.myapp.)
But when classes are stored in an archive file (a .zip or .jar file) the class path entry is the path to and including the .zip or .jar file. For example, to use a class library that is in a .jar file, the command would look something like this:
% java -classpath /java/MyClasses/myclasses.jar utility.myapp.Cool
Found in http://docs.oracle.com/javase/7/docs/technotes/tools/solaris/classpath.html
You need to add a Class-Path entry to the manifest file (META-INF/manifest.mf) inside the jar:
Class-Path: /C:/.../MyProgram/ .
This assumes that there are dependent classes under C:/.../MyProgram/, not jar files.
You should also add an entry for the Main-class:
Main-Class: main.Main
Then just execute your jar as
java -jar MyProgram.jar
Set the path of JAR file in your classpath and then execute the other JAR file.
To add JAR using eclipse.
Right click on project -> properties
Java Build Path -> Click add external JARs.
This will add JAR to your classpath.

Making a jar file run specific files first

I've made a jar file for all my classes and yes it works. Although it's not running my custom GUI. I'd like to set the jar file to run my GUI before anything else, and from there the rest of the files will be executed.
How would I do this? Thanks in advance.
When I run it through the command prompt using
java GUI
it works, but I need to do this using a jar file as I want my class files obfuscated.
I presume you jave just .class files now and you want to create a .jar file.
To run a jar file you must add -jar after the java command.
Jar files are zip files which contain the classes, possibly resources and a manifest that tells which class has the main() method.
The jar command is used to create a jar file.
jar cvfm output.jar Manifest.txt *class package1 package2
and in Manifest.txt you should have this line:
Main-Class: MainClass
After that just run:
java -jar output.jar

Tool for creating jar files from command line

I'm not very skilled in writing batch files and/ or java. I have a folder with several .class-Files and folders in it and I want to put them all into a executable .jar-File. I know that there is a tool called "jar - The Java Archive Tool", but that just won't work for me. My folder structure looks like this:
Folder "test"
File (a.class)
Folder "subdirectory"
File (b.class)
I want a executable .jar-File called file.jar. In this .jar should now be the file a.class and the folder subdirectory with the file b.class in it.
I don't get the .jar-Tool to run and the 7zip command line doesn't support .jars (I can't even add files to it). I want this to run from a .bat-File, so I just have to open the batch-file, it creates the .jar and puts the files in it and then closes itself again.
I hope you can help me and get what I mean.
If you have issues in executing jar command, then probably you would need to check if your path has been set correctly. You can verify if the path contains jdk location ( echo %path%) from command prompt. If not you need to update. Also you can verify using Javac -verbose command to see jdk is installed.
Once you have jdk path set, you can try below command to create jar
Jar -cf myapp.jar * --> includes all files including files from sub folders.
If you want to run from batch, you would need to mention path before jar command. Ideal place for path is to configure as environment property.
Create a text file (and call it something useful like manifest.txt). In it, put the line:
Main-Class: a
(which should be called A by convention) and include a hard return at the end.
Then create the jar with:
jar cvfm file.jar manifest.txt *.class
or
jar cvfm c:\somedir\file.jar c:\somedir\mainfest.txt *
You could just put that line in a batch file called createJar.bat and run it if you only want to create files called 'file.jar'
hth

Conversion of .class to jar and .class to exe

How do I convert:
class file to jar file using cmd?
class file to exe file?
jar file to exe?
Can I convert exe file to jar file?
Class files to jar files
Usage: jar {ctxu}[vfm0M][jar-file]
[manifest-file] [-C dir] files ...
Options:
-c create new archive
-t list table of contents for archive
-x extract named (or all) files from archive
-u update existing archive
-v generate verbose output on standard output
-f specify archive file name
-m include manifest information from specified manifest file
-0 store only; use no ZIP compression
-M do not create a manifest file for the entries
-i generate index information for the specified jar files
-C change to the specified directory and include the following
file If any file is a directory then it is processed recursively. The manifest file name and the archive file name needs to be specified in the same order the 'm' and 'f' flags are
specified.
Example 1: to archive two class files into an archive called classes.jar:
`jar cvf classes.jar Foo.class Bar.class`
Example 2: use an existing manifest file 'mymanifest' and archive
all the files in the foo/ directory into 'classes.jar':
jar cvfm classes.jar mymanifest -C foo/ .
Convert jar files to .exe file
1)JSmooth .exe wrapper
2)JarToExe 1.8
3)Executor
4)Advanced Installer
Convert .class to .exe is discussed in length here
You must have missed this. Please look into Java Archive (JAR) Files Guide.
And surely missed Real's How to for it Make a JAR executable There are multiple wrappers that do this work (converting Jar to exe, platform specific). You just need to search in StackOverflow for Jar exe
To convert (actually, package) .class files into .jar files, you use the jar tool. You can then generate a .exe file from the .jar using tools like Launch4j, JSmooth or several other packages (search the web for "jar exe").
If you are using Netbeans IDE, then creating .exe file from .class file won't take much time. In IDE, create a new project and put your java program in this project. Now follow these steps-
Right click the project and choose properties.
Choose run from left panel and enter the main class(in which main method is defined) in right panel.
Again right click the project and choose add library. Select swing layout extensions. Click add library.
4.Now select clean and build from run menu in your IDE. Make sure that you have already set your this project as main project.
Open the CMD and set the directory to your project. Go to "dist" > and type java -jar jarname.jar.
Your program is running in cmd now.
Open launch4j and provide the information required.
Run and enjoy your application.
Create jar file using command line. Answer in http://download.oracle.com/javase/tutorial/deployment/jar/build.html
Class to exe. Answer in http://www.javacoffeebreak.com/faq/faq0042.html
Jar to exe. Answer in http://viralpatel.net/blogs/2009/02/convert-jar-to-exe-executable-jar-file-to-exe-converting.html
Converting exe to a jar file is possible. But involves reverse engineering to discover what is in the exe, extract and do whatever you want with it. In my opinion, is not worth at all.

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