In that case the below command would suffice: jar cf helloworld.jar helloworld You can ignore the manifest file if you just want to create a java library and not a java application that needs to be executed. Once run the jar file gets generated in bin folder:Įxecute the jar file using the below command: java -jar helloworld.jar Also you can use wildcards (* takes all the packages and files from the current working directory). This is followed by the manifest.txt file which contains the addition to MANIFEST.MF fileĪnd that is followed by the package name which contains the java classes (if there is more than one package name you can specify them separated by spaces). Next to the above arguments mention the jar file name (.jar is optional) In our case we are going to tell Java which is the main class it should run. M means you are going to modify existing manifest file using the information in the supplied file Here is the jar command : jar cfm helloworld.jar manifest.txt helloworldį means you are going to create a FILE(jar file) Run jar command by specifying few parameters. This is needed for java to recognize the file. Notice that the name starts with the package name followed by dot followed by the class name with no extension.Īlso notice the cursor in the next line (you should enter a newline character – by pressing ENTER key ).
#How to make a java jar file how to
Second, well see how to read the content with BufferedReader, Scanner, StreamTokenizer, DataInputStream, SequenceInputStream, and FileChannel. First, well learn how to load a file from the classpath, a URL, or from a JAR file using standard Java classes. Let’s first create the manifest file, I have named it manifest.txt and placed it in bin folder :Īdd the name of the main class next to Main-Class keyname like below in the manifest file: In this tutorial, well explore different ways to read from a File in Java.
Go to the bin folder where the class files got generated This can be done by creating a new file and telling java to add the information in the file to the manifest file already created.
When you create a jar file you need to tell Java which is the main class whose main method should be run by JVM. By default it contains Manifest-Version and Created-By fields in name:value pair format. This file contains meta information about the application. Now when you create a jar file by default java generates a manifest file (MANIFEST.MF) under META-INF folder. On building the project the class files got generated in bin folder like below: I created a simple HelloWorld application which has a single class named HelloWorld.java under the package helloworld which prints the text Hello World! to the console. This post explains the steps to convert a java application to a jar file using command line. You want to run the main method of a particular class in your application when the jar file is executed. Hopefully, at this point you have a picture like I have below in your folder.Let’s say you created a standalone java application and you want to execute it as a jar file. No problem, instead of the last line up above, type: C:\> C:\Path\to\jdk\bin\jar cvfm jarDemoCompiled.jar manifest.txt *.class Remember the path to jdk\bin\jar will be similar on your computer but almost definitely not exactly the same as mine. Here's the actual screen shot from my command prompt. When I don't usde the shortcut on my computer, I must type:Ĭ:\> C:\"Program Files"\Java\jdk1.6.0_02\bin\jar cvfm jarDemoCompiled.jar manifest.txt JarDemo.classĬvfm means "create a jar show verbose output specify the output jar file name ( jarDemoCompiled.jar) specify the manifest file name( manifest.txt) and use the file JarDemo.class to create the jar You can set the path as followsĬ:\> jar cvfm jarDemoCompiled.jar manifest.txt JarDemo.class
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