As the title states, I'm trying to use javap with eclipse but have difficulties setting it up. I'm trying to set it up using external tools from the run menu but can't find the correct Arguments: string to make it work. Basically I need something that will dynamically execute the current file I have opened.
I use the following external tool configuration to achieve this:
${system_path:javap} is used to locate javap in the JDK used by the Eclipse. You can use an absolute path to javap instead.
${project_loc} returns the absolute path to the project. This is used, since I could not find a pre-define variable to use, to locate the .class file of a resource, and that's why javap runs in the project's directory instead of the directory containing the .class file.
Among the arguments passed to javap:
bin is the default output folder for Eclipse projects. Change this to build/classes or whatever is used by the project. Note, the value is relative to ${project_loc}; you can specify absolute paths instead.
${java_type_name} is used to obtain the selected class name.
You can select a Java file in the Project explorer view or Project navigator view, or even a Java type in any of the views, and then run the external tool. Note - this approach doesn't work quite well when you select a method, an inner class etc. and then run the tool, as they are not resources on their own, leading to the scenario where ${project_loc} will be empty.
Your problem is that javap requres path to class file but when you select your source file you can access eclipse variable ${selected_resource_loc} contains path to java source. As far as I understand there is no variable that contains path to class file.
I think that the easiest way for you is creating your custom script that accepts path to java file, replaces java to class and source folder to bin folder. If you are using linux it it can be easily done using command sed. If you are on windows it can be implemented using command SET with ~. See help for more details.
Good luck.
Please try by modify the Working Directory to match your java project output folder. In my case, it looks as given below.
Working Directory: ${workspace_loc:/Sample/bin}
Then I selected the .class file and executed the javap without any issues.
In order to disassemble the currently selected .class file in Eclipse I use the following arguments in the External Tools Configurations.
This way classes in subpackages of the bin folder can also be disassembled. The output is displayed in the Console view.
Oracle documentation of javap parameters.
In-addition to the valuable custom script suggested by #AlexR; the other way is : Open the terminal windows within the Ecplise and run the javap command with -p and other option.
Related
I have a java codebase with many packages which I'm not that familiar with.
I just want to get an overview by javadoc-ing the while thing. Without having to specify the names of which packages I want to document. I just want "everything"
Is there a simple command line option for this?
Update :
I would have just expected to be able to write something like
javadoc -d /home/html -sourcepath .
to get all the packages defined under the currect directory
But it doesn't seem to work that way. But what would be the way to get that?
GUI based answer, unrelated
An easy and cozy way (requires IntelliJ):
Open the project.
Open the Tools menu.
Click on Generate JavaDoc....
In JavaDoc Scope, choose the Whole project radiobutton.
If your project is in C:\JavaProject and the source files are in C:\JavaProject\src,
Use command:
cd C:\JavaProject\src
followed by:
javadoc -d C:\JavaProject\docs * -subpackages *
Warning:
This method will fail if it encounters a subdirectory that is not a package or source.
It will also fail if files are present in src or if a directory is empty with the message error - No source files for package.
Here's a GitHub repo for you to clone and try this out.
I would like to make a Java package in a JAR file with precompiled classes such that other Java projects can consume these. How do I do that? It seems to me that most guides I have found expects a Main class/method to be available, but I do not want this to be an application that runs by itself. Furthermore, the resources (various files) inside of my project should be put into the JAR, since my app depends on these. Is this possible? I am (by the way) using Gradle.
A claim has been made that this question is a duplicate of this: Java creating .jar file. However, this question assumes the existence of main methods, and it does not concern how to include resources.
You can create the jar from the command prompt.
Copy all the classes that you want to include into a folder.
Then open that folder in command prompt and issue this command.
jar cfv YourProjectName.jar *
And a JAR will be created in the same folder containing all the classes.
Another solution:
If you are using eclipse try:
Right Click on the Package -> Export -> java -> jar file
You could also select the Classes and right click on them instead of the Package.
Edit:
Refer to https://docs.oracle.com/javase/tutorial/deployment/jar/build.html for more details on this command.
you can put all your methods/functions in class file then export it to .jar
then add the jar to your project's build path. Now you should be able to call those functions from your current main java class.
I tried to run FindBugs in command line and had troubles when specifying the project to be analyzed. I understand FindBugs works on bytecode (.jar, .class), so I wrote a HelloWorld program and made sure that it had some messy code that would be detected by FindBugs.
Then I tried:
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld/bin
which threw an exception:
java.lang.IllegalArgumentException: Can't read project from HelloWorld/bin
at edu.umd.cs.findbugs.Project.readProject(Project.java:774)
I also tried .class and .jar files, but nothing showed up:
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld/bin/Main.class
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld.jar
I checked the FindBugs manual about the command line option "-project", it says
The project file you specify should be one that was created using the GUI interface. It will typically end in the extension .fb or .fbp
I don't understand this. Does it mean that some pre-processing is required and FindBugs cannot check arbitrary .jar or .class or project directly? How can I get this .fb or .fbp extension?
Thanks.
The procedure is described on the FindBugs website:
Make sure you download the FindBugs distribution which includes the GUI (called Swing interface).
Extract your downloaded ZIP and add its bin folder to your PATH.
Type findbugs to open the GUI, then click New Project
In the dialog:
Enter a project name, say HelloWorld.
Where it says Classpath for analysis, give it the Jar with your .class files or a directory where the .class files are (such as build/classes/main or whatever; the package structure must start in this directory).
Where it says Auxiliary classpath, list any libraries required to load your classes.
Source directories works just like Classpath for analysis, but for .java files. FindBugs uses this to show you where in the code your issues are.
You can select (cloud disabled) as bug store.
Click Analyze.
Now you can save the project configuration as a .fbp project file.
Next time, you can start the analysis by running
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld.fbp
If you don't want to or cannot use the GUI, you can get the text-only version by adding the -textui option as first option after findbugs.jar. Output formats and behavior are configured via additional command line options.
However, most people use FindBugs integrated with their IDEs, or as part of a build process. Neither use case should require the GUI or command line versions. Take a look at the plugins for your IDE, it may save you a lot of time and they are really easy to use.
Basically, my program compiles and runs fine in Eclipse but doesn't compile in Command Prompt. It gives me Symbol Not Found with the pointer on the name of one of my classes. I've never had this happen before- the only difference between this program and the other ones I wrote is that I made a package in Eclipse for them. Any ideas?
I think you didn't set the path correctly.
How to set Path in Java
The path is required to be set for using tools such as javac, java etc.
If you are saving the java source file inside the jdk/bin directory,
path is not required to be set because all the tools will be available
in the current directory.
But If you are having your java file outside the jdk/bin folder, it is
necessary to set path of JDK.
If you did not do it already, it might help if you remove the package declaration in the java files. If your compiling class uses any other classes, they will not be compiled because of the package declaration. It happened with me once.
Pretty basic problem here. So I have a Java package that I have created that has three classes (one has the main method). I am trying to use a few Apache Jars, and have added these to my build path in Eclipse. However Eclipse wont let me build and run it properly, so I am trying the command line. I have added the env var CLASSPATH and pointed it to my lib directory which hold the Apache Jars. However, when I try to use javac I get a bunch of errors:
package org.apache.xmlrpc does not exist
import org.apache.xmlrpc.client.XmlRpcClient;
I was reading the man page for javac and it said that:
If neither CLASSPATH, -cp nor -classpath is specified, the user class path consists of the current directory.
So I tried copying the Jars to the same location as my three source files, but no change.
Can someone please tell me what I'm doing wrong?
Thanks.
Classpath variable (or command line option of javac) must contain all jars explicitly. It cannot go through jar files stored in specified directory.
You can compile this by specifying the option -cp on the command line:
javac -cp foo.jar:bar.jar foo/bar/Baz.java
You then run it with the same option:
java -cp foo.jar:bar.jar foo.bar.Baz
It sounds like you've just set the classpath to the directory containing the jar files. You need to set it to the individual jar files, or use java.ext.dirs to set an "extension" directory containing jar files. I'd recommend using the specific jar files. Something like:
// Assuming Windows...
CLASSPATH = c:\libs\foo.jar;c:\libs\bar.jar
I'd also personally recommend specifying the classpath on the command line instead of using an environment variable - the latter will work, but it ends up being a bit more fiddly if you want to compile different projects against different libraries.
However, I'd actually recommend getting Eclipse working first, rather than retreating to the command line. It should be fine - if you could give us more information about what's failing in Eclipse, we may be able to help you with that instead.
The jar files in the current directory are not automatically included; that only refers to .class files in normal package/directory hierarchy. Jar files must be added either explicitly, or via a wildcard like javac -cp ./* (Assuming JDK6+)
(Some OSes may require an escape of the * to avoid globbing; OSX does not.)
I agree with previous answers, but I would also recommend to use proper java build tool - like ant (perceived easier to use, but not necessary) or maven ( perceived more difficult to use, but really worth learning )