I want to follow a Java program so that I can understand how everything works together. I could do it with Visual Studio so I am hoping that Eclipse may also have a feature to step through that I have not been able to find.
Put a breakpoint at a given line (double click before the line, or right-click > toggle breakpoint)
Run the program in debug mode. That is - Debug As > Java program
Whenever the breakpoint is reached, the Debug perspective opens, and you can step through.
Refer step1, step2, step3,step4 images respectively.
Simply put, you can run your code in Debug Mode by pressing only F11 or clicking that little bug on the top of the screen. Use F5 to trace into, F6 to step over, CTRL-SHIFT-B to set/remove breakpoints.
First you must set a break point in your code. The easiest way to do this is to open up the source file where you want to stop your program, find the line of code where you want to set your break point, and right-click the left-hand margin and select 'Toggle Breakpoint.' Once you've done this, launch your program within Eclipse using the Debug mode. To do this, go to Run>Debug Configurations and set up the configuration to run your program. Alternatively, you can open up the source file that is the entry point to your program (it should include your 'public static void main(String args[])' method), and right-click within the editor and go to Debug As>Java Application. Once the program launches and the code in which your break point is reached, Eclipse will open up the debug perspective. This will show where you are within your program and any variables that you have set. You can step through your program using the buttons in the 'Debug View'. You can also use the menu items within the Run menu to step through the program.
All the answers here are not really "cut and dry". To make this debug feature available in the eclipse workspace, first, you need to set the breakpoint properties of Line Breakpoint. Check the box: "Trigger Point" to allow the trigger to initiate at the line that you want it to begin to break during debug mode. Otherwise, you can F11, F5, or F6 all day long, and nothing will allow you to step into your code.
Related
I used a hint that said use Run with --debug, so I clicked on it. How can I remove the feature to get an output as usual?
Clicking this link will create a new temporary configuration for Gradle that will have --debug argument added there:
You can either remove this argument from the configuration or delete this configuration completely and continue using your existing run/debug configurations without this option.
More details can be found in IntelliJ IDEA help.
Click the red square on the top right, like here:
Alternatively you can also press it in the tab where you can control the debugger, which is on the down left:
If you don't see that, make sure to click on "Debug" on the bottom bar.
I am new to Java and using Eclipse IDE Photon Release version 4.8.0.
I cannot display variables.
I have tried the followings in accordance with previous online Q&As only to fail:
(1) Select a variable -> right click -> select inspection
* It didn't work because inspection is not on the right click menu.
(2) Window -> Perspective -> Reset perspective
* It didn't work.
(3) Window -> Show view -> Other -> search "variable" and open "Variable View"
* It opened the Variable View window, but nothing is displayed. Changing layout didn't help.
How can I display information about the variables? I would like to see their values step by step when debugging a programme.
U need to enter into debug mode to see the results line by line
There are two aspects:
1) Putting Breakpoint
2) Running in debug mode
Double click on any line it will add a breakpoint on that line, now click on green bug icon(debug)/debug as
it will run the application in debug mode
It will stop at that line and will ask to switch in debug perspective, select yes
[imp] now if u can't see variable view select
window->show view->variable
here u will see all the variables in scope, press F6 and it will proceed line by line debugging there u will be able to find the variable value at each line
Put breakpoints where you want the debugger to stop and inspect variable values.(Double click on left side of the line to put a break-point)
Run your java code in debug mode.
Eclipse will open debug perspective automatically for you when it stops at the break-point.
In this window you can see the variable values and other properties in 'Variables' view. (Mostly present on the top right in Debug perspective)
Enter in debug mode and enable the variable view using the (3) option. When you are stopped at debug, if the view of variables is empty, close it, and now, without stopping the application, perform the reset using step (2). Now try to enable again the view using the step (3).
I had the same problem. The solution was as follows.
eclipse menu -> Project -> Clean -> Clean all projects
After that, I did restart eclipse IDE.
It works for me.
And you should check your administrator privileges.
Run javaw.exe, java.exe as administrator.
I have encountered a problem with the Eclipse and I am unsure how to fix it. When I enter the debugger and press the step over button the debugger usually highlights the line of source code that I stepped to. However, for some reason this is not working for me anymore. I enter the debugger and go to the breakpoint but if I hit the step button the source is not highlighted and if I continue to hit the step button I can see that the Debugger is stepping into other files (looking at the Thread) but my view of my code doesn't change. The only way I can find what line my Debugger is on is if I control click on the line from Debug tab and click Lookup Source which then highlights the line the Debug Current Construction pointer is on. If I am debugging I would like to follow this Current Construction pointer line by line. I must have accidentally altered this somehow and I am unsure how to change it back.
Simply stated the problem is this, usually the Eclipse Debugger highlights your source code as you step through it. It is not doing that for me anymore, the debugger is stepping properly but it is not highlighting the line of code that it is on.
This happens when we make Java code change in file, compiler creates a class but running server has a old copy of your class file.
Go with JRebel to get rid of such kind of issues.
This can also happen if you have more than one project in you work space, and you create a debug configuration that points at the wrong project base directory.
To resolve this:
Open your debug configuration list (Run -> Debug Configurations)
Select the proper configuration under your Remote Java Application list
Verify that you have the correct project source listed under the Base directory on the Main tab.
If you have the wrong directory selected (say, one that holds a different project), the debugger will start with no issues, but you will not be able to step through your code.
I had the same issue.
There was a workaround for that by right-clicking on associated callstack line in Debug view and selecting "Lookup Source". After that the current instruction line is (green) highlighted as usual. But I needed to do this after every debug step.
Rebuild all projects didn't help.
The solution:
Restart Eclipse and all works fine.
I have a problem in Eclipse (with Java 8) that I add a breakpoint for a function in some class in the project. But when the debugging starts, it is from the beginning of the program (from the main method!). Of course, I do not want to follow all the program so please what can I do?
Take a look at the "Debug/Run Configuration..." and uncheck to button to start in debugging in the main method.
how to setup "Main Class" in "Run Configurations" in Eclipse
Uncheck/Check "Stop in main".
Is this what you want to do?
Possibly you have a class or method breakpoint...
You can press F8 key to jump to next point or you can
Delete the breakpoint.
To modify them: open debug perspective and take a look to breakpoints:
if you don't have this, please take a look to other answers. ;)
Select your debug configuration from menu Run->debug configurations...
Go to main tab and uncheck Stop in main checkbox.
I use Eclipse as IDE and I have a problem with breakpoints in this one. I have two projects - an android that I use as client app application and another one that I use as library for first one. Previously i have created an breakpoint in code of library application. Then this breakpoint was removed from sources. But now when I debug my code this breakpoint still hits (the file with *.class extension is opening and this breakpoint is showing). How can I disable or delete it?
Open the project > select the debugging view >> Somewhere in that view there will be a window titled Breakpoints. From there you can remove the breakpoint you want to get rid of.
In eclipse try the following:
Goto windows -> open perspective -> other -> debug
click on Breakpoints tab in the
Remove all/specific breakpoint by clicking on either cross/double cross button