Creating and using custom JAR in Android project - java

I am trying to create and use jar file in an Android project under Eclipse. I have tried various methods without any success. Here are the steps:
Create jar file from the source files jar -cf lib.jar *.java
Copy jar file to libs folder
Right click, Build Path->Add to Build path
Now, compiler gives unresolved symbols if I try to use a class from the jar file?
Can someone please let me know correct method to create and use an external jar file for the Android project under eclipse.

This worked fine for me:
1)Place Jars in assets folder.
2)Right click on project name.
3)Select properties.
4)Select Java build path.
5) Select Libraries.
6) Click Add Jars.

Related

Trying to add external Jars to a Java Project (without Maven)

I am trying to add external jars to my Java (without Maven) Project.
But I don't get it to work at all.
The official documentation: https://code.visualstudio.com/docs/java/java-project
says there are 2 ways to do it:
1."You can use the Java Dependency Viewer to add any JAR file to your project."
https://code.visualstudio.com/assets/docs/java/java-project/manage-dependencies.gif
As you can seee in the gif, the dev opens a "referenced libraries" folder.
This folder DOES NOT EXIST for me.
or 2."The other easy way to bring additional JAR files as dependencies is to create a lib/ folder in the root directory of the standalone files and place your JAR files there. Source for foo.jar is automatically detected if there is a foo-sources.jar in the lib/ folder."
https://code.visualstudio.com/docs/java/java-project/lib.mp4
I have the Jar file in the lib\ folder but it still shows me he same error messages.
Are there any steps I am missing?
As it says, place the external jar files in the ...\JAVArpg\lib folder.
So copy them from wherever you have them now. cp ../lib/*.jar lib/ is just an example.
You can use the Windows Explorer. You don't have to copy the files using a command-line.

Eclipse Java Build Path Jar Library classes not found even if available in jar

Recently I wanted to add the nebula shelf to my eclipse plugin. Therefore I added the org.eclipse.nebula.widgets.pshelf.source_1.1.0.201701302244.jar the build path of my eclipse project.
Sadly eclipse can't find the class files inside of the jar, even after cleaning and rebuilding the whole project.
Picture:
Checking the same jar file with jd-gui results in:
Picture:
I exported the *.java files with jd-gui and copied them to my project. Using this method my project built successfully and worked as expected.
Can someone tell me how I can use the jar file without exporting all of the java files manually? Thanks for your help! :-)
Do not use source jars. You can tell eclipse while debugging to use the source jar.
Add the jar to build path: right click on jar -> build path -> add to build path
Don't try to add Eclipse plugins directly to the build path of another plugin as it won't work.
Instead add the plugin to your target platform or import it in to your workspace.
Then add the plugin to your plugin's Dependencies. In the MANIFEST.MF editor you do this on the 'Dependencies' tab in the 'Required Plug-ins' list.

why eclipse not detect the jar file from lib folder

I am trying to develop java desktop application using eclipse and using some external jar file in project.
I have put that all jar file in /lib folder (this is desktop application so here /WEB-INF does not exist) now the problem is that the application cannot detect external jar file what is the problem ? and how I can solve this problem?
You need to add external jar file as :-
Click Properties > Java Build Path > Libraries.
Click Add External Jars and browse to the JAR file that contains the look and feel, then click OK.
Now, you are ready to apply the new Look and Feel to your application.
You have add it to classpath as well. right click on project and click add to build project.
click libraries tab and click external jar files. select your jar files. It will be added to classpath.
I think you have to inserti it. Rightclick in project properties build path, add external jar and browser to it.
just put jar file into the libs folder and abb to build path thats it. Updated eclipse not getting jar or configure file from the lib they get jar file from the libs folder.
You can right click on your jar file and choose Build Path and then choose add to build path

Creating a .jar in Android

I have a Android project with some classes that I would like to compress to a JAR.
I create the JAR by right clicking my project - export - JAR - and the JAR gets created without any warnings.
I can access all classes from the JAR in my code but when I try to build the project get this exception :
java.lang.NoClassDefFoundError: name.of.class.in.package
Does anyone know what resources should be exported with the JAR? The options you get is
.class path
.prject
AndroidManifest.xml
proguard.cfg
project.properties
Right now I have included all of the above.
Making the JAR into a library project is not an option. And just to make it clear I don't have anything in the RES folder of my JAR project.
Open the project properties -> Java Build Path -> Order and Export and check item Android Dependencies are checked to be exported to the result APK.
And if .jar exist in Library tab under Android Dependencies item.
If you have .jar in the "libs" folder it should be included by default.
Just add your JAR to classpath or build your project with Maven and include dependencies
Try generating the jar in a different way. Basically jar is a zipped file of all class files with an extension of .jar.
Select all your class files that needs to be included in a jar file.
Right click and send to compressed (Zip File).
you will have a zipped file which will contain all the class files.
Rename this zipped file with having an extension .jar
Now include this jar file into your project whichever you want to use.
Or if you want to zip all the files by a different method then make sure all the files are zipped together without a folder. So when you unzip the files you should get all the files without contained in a folder.
It looks similar with this topic. Follow the very clear instructions written by Russ Bateman.

Creating Android .jar files

I want to create an Android project that contains some code, and then export that code as a .jar file to use it on another Android project.
I've already tried to create an Android project and set it as a library in the properties, and then export the project as a jar file. Aparently everything works fine, when I use my .jar file as a user library in another Android project my code inside the .jar is visible and everything compiles fine. But when I run my application it closes and say that it could not find the classes inside the .jar file.Any sugestions will be very appreciated!Thanks in advance.
Look at Project->Properties->Java Build Path->Order and Export. Make sure your jars are exported as well as imported.
Make sure your JAR is in the libs/ directory of the project using the JAR, and that it is in your build path in Eclipse.

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