I need a diff library for my project. This is exactly what i need: http://code.google.com/p/google-diff-match-patch/
But when i download the file it doesnt come with a jar file. There are source codes in it and i'm not quite sure how to add this into my application. Anyone knows how to use this in an application? I really appreciate an answer.
The only thing you need to add to your application is the diff_match_patch.java file. (Make sure its license is appropriate for your code.)
It doesn't have any dependencies so you can simply compile it with javac diff_match_path.java.
The diff_match_patch_test.java uses the API (obviously) so you can look in there to see examples of how to use it/what to expect. (The test class depends on jUnit.)
If you want to separate it and put under your lib/ folder, then create a new Eclipse project, copy diff_match_patch.java to src folder (with package name of course), then use
File->Export->JAR
feature of Eclipse. By this way you can have this file as a JAR archive. This will provide a neat way to keep dependencies organized.
Related
Is there a way to make changes in jar which doesnot have source code in it and rebuild it with this change as a jar in eclipse.
You can look into using Java decompilers; in order to turn the .class files within the JAR archive back into .java source code. The process and some tools for that are outlined here.
But: understand that *decompiling" can be a tough business! Plus: there is always the question if the licence terms of the library you are using allows you to do that. Being able to do something isn't the same as being allowed to do that!
Finally: keep in mind that a JAR is just a deployment artifact. A lot of libraries are open source, and you can most often download that source and build the corresponding JARs completely on your own.
I'm in the process of writing a small Java library that contains a related code that I usually include in most of my android app. I decided to export the library as a jar file then drop the file in the libs folder of my future projects.
Using Android Studio:
I created a Java Library module and put my code in it. And I added some comments to some of the method, following this.
Then, I ran the jar task in gradle, which gave me the .jar file in build/libs directory of my module.
Now, when I used this jar in one of my android apps, Everything works as expected, except the Doc part. When I hover over the classes and methods of my library, I don't see the Doc comments that I wrote.
Q1: Am I missing another step?
Q2: Are jar files supposed to have no comments?
The javadocs are the documents that are generated from the javadoc comments in your source code. They are not part of a normal JAR file because that would unnecessarily bloat the JAR files ... with stuff that someone running to code doesn't need.
The javadocs can be generated by a Gradle task, by the javadoc command (if you have a Java SDK installed) and by various other tools. You can then read them using a web browser.
On the other hand, IDEs can often render the javadoc comments in source code and display them as pop-ups, etcetera. (Some people would call this "javadocs", but I think that is an overstatement, since you typically can't navigate the documentation ... like you can with read javadoc documents.)
In order to render the javadoc comments, the IDE needs the source code. JAR files don't (normally) contain any source code or javadocs. Instead, the normal way to deal with this is to tell the IDE where the source code is, either by pointing it at a source code directory, a ZIP file containing source code, or URL for downloading the source code.
(I don't use Android Studio, so I can tell you exactly how to do this. However, I imagine that the IDE's online help explains how to do it ...)
It seems that your end goal here is to distribute your libraries in a way that allows programmers to see the javadoc comments.
The simple way to do that is to distribute source code. This Q&A describes how to get Gradle to generate a separate archive containing the source code, or add the source code to the JAR containing your compiled code1.
If that isn't acceptable, you may need to generate the javadocs as HTML2 and provide the HTML tree as a separate ZIP file that a programmer can unzip and read with a web browser. Alternatively, put the javadocs up on a website.
1 - I would not recommend this. People who just want to use the JAR as a binary are liable to complain about "bloat".
2 - If neither providing source code or javadoc HTML documentation is acceptable, I don't think there is a pragmatic solution.
There is a separate Gradle task to generate javadoc. Try adding the following:
task javadocJar(type: Jar, dependsOn:javadoc) {
classifier = 'javadoc'
from javadoc.destinationDir }
And then run:
gradle javadocJar
See if that helps.
In addition to the above, you can try and add the following to make to generate a single jar with both compiled classes and javadoc:
jar {
from javadoc.destinationDir
}
jar.dependsOn javadoc
I don't know if that's the right decision to bundle everything in the same jar. I prefer keeping the jars separate and maybe find another way to make the IDE use the javadoc jar file. Maybe try adding the javadoc jar as another dependency of the module.
Yes This is possible
Hi, This is possible but with a small change like in the jar file.
First of all, from a code point of view jar file contains only compiled ".class" files and not source files ".java"
So if you need a doc to be applied with a jar by this I mean not the index.html which gets created but the comment that appears whenever a person uses the jar API and calls a method with a suggestion.
Example :
For that, we need to also add a source file while generating .jar file.
Steps for the same:
Type comments/java docs in code
Generate Docs
This will create a doc folder in project folder
Now create jar file
Make sure you choose this option as shown below
Almost done just test it by importing jar to another project and it should the suggestions as per docs
Very Important this can be harmful as you are including source files.java in your jar so before making make sure if you need this or not.!!!!
Hope this gave your answer
Any questions you can contact me over: VaibhavMojidra.com
I do not have the latest source code but have the war(up to date) file deployed on server.
Please suggest the best ways to
1) Retrieve source code from war/ear
2) Compare & Merge/update the available source code with the code present in war/ear but missing in available source code(I am using ECLIPSE IDE)
Thanks in advance
War files are basically zip files, so they are easy to extract. (using unzip or just renaming the file)
Next you could use a Java decompiler like JD.
But you won't get the original Java code as the compiler does a lot of optimization.
But it should give you a good starting point
Once you've extracted the classes from the EAR/WAR/Jars, use JAD to decompile the code you're interested in to get back to the source: http://varaneckas.com/jad/
I'm not sure there's any out-of-the-box tool that is going to compare/diff your original source with the decompiled source produced from something like JAD though. Also bear in mind, decompiling classes back to source is not going to produce source that looks identical to the original source - code style is going to be different, maybe even some structure of the code. It's going to be difficult to do a diff between the original source and decompiled source.
If you have the original source but not the source for the code that is currently deployed, maybe a better question is to ask 'why not'? If there's something missing in your build process where you are not tracking what source is being used for each build, maybe this is an easier issue to address moving forward, rather than trying to do something clumsy and error prone like a diff between some other source and decompiled source?
The exact answer: it is not possible to get the original source code (.java files) from a war as opposed to a jar (java archive). When you create a jar file, you can decide if you want to include the .java files. Only a java decompiler can help, see the other answers.
Using JD GUI you can the source code with java code, but you'll need to
Inside the war folder, under specific module - Based on your project hierarchy (if maven project -these config will be available in Pom.xml - it will define which path and what jar name)
you will have the Core JAR files of each module.
Open those jar files using any decompiler , you will be able to find the class/java files in it..
Here is your complete solution.
If while creating war file, you have to make sure that you have added the code.
Otherwise, do one thing.
Deploy the war file in your server, may be on tomcat server.
To deploy the war file, you need to put that war file in webapps folder (C:\ASHIS_CODE\apache-tomcat-9.0.65\webapps).
enter image description here
After putting, you need to restart your tomcat server.
Then one folder with same name as of your war file name, will be created in side webapps folder.
Open that folder in your eclipse or any other ide, that folder contains your project code.
** Hope this clears your issue.
I think this is a super easy question, but im new to this and not sure what to do. So I have added an external jar file into one of my projects, and was able to decompile the classes using JAD to see some of the class files, the thing is I want to add a new class to one of the directories in same JAR file, compile it and update the jar file. I was googling and I came up with things like an 'ANT build file' but not sure how that would work?
Thanks!
First of all i would check out if the developper of that JAR has provided the source to the classes. This reduces the possibility of JAD not beeing able to fully decompile all the class information.
However once you have all the .java files (including your changed or added class) you can let eclipse build the jar file as follows:
1.) Compile the .java files (Project -> clean..)
2.) File -> Export -> Java -> Jar file (click next)
3.) Select anything that belongs to the jar, input a name and click finish (Note the checkbox that says to export generated class files and resources).
Regarding Ant/ Maven and stuff: Those are just tools that help you. The same result you can archive by opening a console and use javac.exe to compile you can use ant or maven to compile your classes. Its just a matter of configuration.
I recomend you skip Ant right here and directly do the Maven in 5 Minutes tutorial :)
Your approach works. But you can have two classes with same name and package. This will remove the necessarily of updating the jar file.
You must set the loading order to make sure that your new modified version will be used instead of the one which is in the jar file.
Possible to use two java classes with same name and same package?
Before any tweak and class loader, test this approach, may be the default class loader behavior will do what you want.
I am trying to enhance a library. The library is in the Referenced folder of eclipse. I presume in that folder I can't just edit the code so I guess I have to import the whole .jar file as kind of a project, but how can I do it in eclipse .....
The right way to do it is to find/download the source code for the library. The ugly way to do it is to decompile the library.
After that, edit the source code, and run against your custom version.
You probably need some sort of Java code decompiler to get the source code for that library and then make an eclipse project based on its source. It will be tedious and you will need to setup the dependencies and all that. However you might want to see if the source for that project is already somewhere on internet, eg open source libraries. One better approach could also be extending that library by means of extending classes and that.