Using .class methods in Eclipse - eclipse

I have two classes, Phone.class and Time.class. I would like to use their methods for my project in eclipse, but I cant figure out how to do it successfully. How do you import the .class files so that I can use their methods in eclipse?

Add the folder containing both classes to the build path for the project: right-click on the project in the Package Explorer window and select the Build Path option, then select the Configure Build Path option. The Libraries tab has Add Class Folder and Add External Class Folder options: use the first if the folder with the class files is already part of the project, otherwise use the second. Select the folder and then hit OK and you should be good to go.

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Eclipse src folder empty

So for my class I need to use eclipse to do some graphics stuff in Java. I've tried both Eclipse standard 4.4 and Eclipse for Java developers, but with both when I tried to create a new Java project, the src folder is completely empty. Why is that?
Edit: I should add in more information. In the lab section of my class I was able to follow the instructions and create a lab 1 project src folder, which contains many files such as Lab1.java, Polygon1.java and all that. When I am trying to do it on my own machine, it's not working
Because it's a blank canvas!!
Right click on the src file New->Class
Give the new class a name and a package and you're away, you can start coding.
If you want to include libraries create a new lib folder at the same level as the src folder and copy any jar folders into this folder. Right click on the .jar files and click Bukd Path->Add to Build path, you'll now be able to import and classes contained in this jar file(s)!!!
Because you created a new project. If you haven't added any code yet, why would there be code in the src folder?

Eclipse Package Declaration Work Around?

The team in which I'm working doesn't use eclipse and wants the src folder to be setup a certain way. I, on the other hand, am using eclipse. They would like the src folder to have, for example, the following structure: src/main/java/com/* However, they would like package declarations to only have com.* in them. If I go to project->properties and in the source tab remove the src folder as a source folder and then _only add the com.* folder as part of the source_ it will show com.* as a package, but I still have to add the whole path from src down in the .java files. Here's an example of what I have to do in order for eclipse to recognize the packages:
package main.java.com.parser;
And what the team wants is to have main and java just be a folder so the package declaration would just be:
package com.parser;
So although the file structure would still be src/main/java/com/parser, the package name would be as stated in the later example.
Is there a way to do this in eclipse? I've seen some people asking similar questions on here, but they seem to have no concern that the whole path must be part of the package declaration.
I would much prefer not to do this this way, but no one else is using eclipse on this project.
Thanks for any help in advance.
In the Package Explorer, right click the src folder and select Build Path > Remove from Build Path
Then find the src/main/java folder, right click java and select Build Path > Use as Source Folder
Basically this tell eclipse that java is the folder which contains the packages and source files.
P.S. This is a very normal project setup for building with Maven. If you download the m2e (Maven to Eclipse) plugins and choose to create a Maven Project (or import from the pom.xml) then Eclipse will automatically know how to correctly locate the source folder.

.class file opens instead of .java while debugging

Current setup:
MainProject which is a Library Project
BranchProject which is a new projects and has MainProject as a Reference
Whenever I debug and a file from MainProject is on focus (actually BranchProject has only graphic and xml layout changes) the Debug window opens a .class file which is read only. I want it to open the .java file so I can edit it directly.
Skyler's answer from this post worked for me:
Opening source code from debug view edits .class after Android R18 update
Here is a summary:
The fix is to right click the Project name in the debug view, and select "Edit Source Lookup..." from the menu. From there, remove the Default lookup path. After that, manually add the associated projects (not jars) that your project references. This is done by clicking Add, selecting Java Project, then checking the appropriate projects.
When you're using a Library project one of the things you're in fact doing is compiling your Library project into a jar and then referencing that jar in your calling Project.
If you right click the Project, and select "Configure Build Path" you'll see a tab called "Libraries", if you look inside "Android Dependencies" you'll notice a list of jar's corresponding to your Library projects.
These jars are expandable, showing you that they have a slot for a source attachment. Usually this would be editable allowing you to directly link the source but in terms of ADT these are already filled and are uneditable.
When debugging these files you're linked to a read-only class file with this attached source. This is because you're not running against source files directly, you're running against a pre-compiled class file. Until the ADT team get this functionality in place, you're pretty much forced to jump to the direct source code and rebuild everything.
EDIT
See #Steven linked answer :)
I faced the same issue while debugging the a .java file using Eclipse IDE. As per my understanding this issue comes when we put the xyz.class file of xyz.java file or JAR at the project build path. Delete the .class or JAR file from the project class path and rerun .java file in the debug mode. This time you see a source not found window. Click on "Source not found" button and check "Find duplicates..." at the bottom of the window. Done your problem is solved :)
The problem is that the class file is preferred over the java (by default), here is how you can change that for Eclipse (tested on NEON 2):
Right-click on the Project in the Project-Explorer, click Properties
On the new window select: Run/Debug Settings
Create a new configuration (or duplicate another one)
Select the new config and click Edit...
Go to the tab Source
Select the Default and Remove
Create a new path with Add..., select Java Library, then JRE System Library
Create a new path with Add..., select the location where the sourcecode is by Workspace folder (if it is a project in the same workspace) or File System directory (it it is not)
I think this depends on, how you set up the dependency in eclipse. You should set up your BranchProject to depend on the source-Files of your MainProject. If you depend on compiles Class-Files is obvious that the debugger opens the class files, because it does not know about the source files.
I found a good solution for me here:
Using Android library in eclipse and jumping to class files instead of source file that is within eclipse workspace
Simply, select each library project your project depends on, and use Top or Up to move it above the projects outputs. Eg. move all library projects to the top.
Open main project properties -> Java Build Path -> Projects tab and add there projects the main project depend on.
Switch to Order and Export tab and uncheck Android Dependencies
Enjoy
If you tried all above hints and it still doesn't work try this solution, it worked form me:
Right-click on the Project in the Package-Explorer, click Build Path -> Configure Build Path...
Select tab Order and Export
select library that you can't reach code and then click on button Bottom
Then click on Apply and Close
hope this can help you
Most of the time it happens when specific source folder are not added in build path Sources tab.
Right-click on the Project in the Package-Explorer, click Build Path -> Configure Build Path -> Source Tab
Add the source folder if your project source folder is not there.
Select Add folder -> select your project source folder specifically. Eg: project_name/src . Then Apply it and restart server.

How to create a Jar file in Netbeans

Well I have my source code that i have done using the IDE netbeans. Now I wanted to move this java application to a web application. For that I need to create a jar file from my source code, so that I could invoke it in ma jsp file.
I have not been able to find any option in netbeans or any other way to create a .jar file of this source code.
Could someone tell me how to do that.
Thanks
Create a Java archive (.jar) file using NetBeans as follows:
Right-click on the Project name
Select Properties
Click Packaging
Check Build JAR after Compiling
Check Compress JAR File
Click OK to accept changes
Right-click on a Project name
Select Build or Clean and Build
Clean and Build will first delete build artifacts (such as .class files), whereas Build will retain any existing .class files, creating new versions necessary. To elucidate, imagine a project with two classes, A and B.
When built the first time, the IDE creates A.class and B.class. Now you delete B.java but don't clear out B.class. Executing Build should leave B.class in the build directory, and bundle it into the JAR. Selecting Clean and Build will delete B.class. Since B.java was deleted, no longer will B.class be bundled.
The JAR file is built. To view it inside NetBeans:
Click the Files tab
Expand Project name >> dist
Ensure files aren't being excluded when building the JAR file.
Please do right click on the project and go to properties.
Then go to Build and Packaging.
You can see the JAR file location that is produced by defualt setting of netbean in the dist directory.
I also tried to make an executable jar file that I could run with the following command:
java -jar <jarfile>
After some searching I found the following link:
Packaging and Deploying Desktop Java Applications
I set the project's main class:
Right-click the project's node and choose Properties
Select the Run panel and enter the main class in the Main Class field
Click OK to close the Project Properties dialog box
Clean and build project
Then in the fodler dist the newly created jar should be executable with the command I mentioned above.
Now (2020) NetBeans 11 does it automatically with the "Build" command (right click on the project's name and choose "Build")

Import Libraries in Eclipse?

I just recently downloaded the dom4j library, but for the life of me I have no idea how to access it. I dropped it in the plug-ins folder and rebooted Eclipse, without success. For some reason finding a straight answer for this is more difficult that I thought it would be.
No, don't do it that way.
From your Eclipse workspace, right click your project on the left pane -> Properties -> Java Build Path -> Add Jars -> add your jars here.
Tadaa!! :)
Extract the jar, and put it somewhere in your Java project (usually under a "lib" subdirectory).
Right click the project, open its preferences, go for Java build path, and then the Libraries tab. You can add the library there with "add a jar".
If your jar is not open source, you may want to store it elsewhere and connect to it as an external jar.
For the Android library projects, I do it as in the attached screenshot:
Right click the project, select Properties->Android and in the library section click Add. From here you can select the available libraries.
If you are importing a jar file, then importing them as jar or external jar, as other posters posted would work. I prefer to copy/paste jar file in the libs folder (create one if it doesn't exist) and then import as jar.
If you want to get this library into your library and use it, follow these steps:
You can create a new folder within Eclipse by right-clicking on your project, and selecting New Folder. The library folder is traditionally called lib.
Drag and drop your jar folder into the new lib folder, and when prompted select Copy Files.
Selecting the Project tab at the top of the screen, and click Properties.
Select Java Build Path followed by the Libraries tab.
Click the Add JARs… button and select your JAR file from within the lib folder.
Your JAR file will now appear in both the lib and Referenced Libraries folders. You can explore the JAR's resources by clicking Referenced Libraries.