I am trying to view the instance variables values of the Arraylist in eclipse in debug mode but apart from the values in the list am unable to view variables like elementData or modCount that are part of the arraylist. I have tried using Watch, Display option as well but to no avail. Below is my screenshot after setting the breakpoint and triggering the program run:
Below is the screenshot that I found in one of the websites where the instance variables like elementData,modCount and size are visible:
In the current version (Oxygen.3) the default formatter for Collection shows only the members of the collection as an array. I'm not sure when the more detailed formatter was removed, but you can easily create a logical structure formatter.
Right click on the variable in the Variables tab and select Show Logical Structure/Edit Logical Structure
Your view will have the Collection entry hilighted, and won't contain the ArrayList entry I just created.
Add a new entry:
Provide the class name you want to format, and a description. Select List of Variables and then add the variables you want to display, providing a code snippet for each one. The code snippet executes as a method of the class.
End result:
In oxygen, "Show Logical Structure" is enabled by default. All you have to do is click on it to disable it.
[Image taken from eclipse.org]
In some instances that I cannot view variables, like in your case, I would suggest using Expression tab and add new expression. To load expression tab on Eclipse IDE, click on Window > Show View > Expression. Set breakpoint, hit debug, then expression tab should load arrNames and you can expand to view properties and data.
Go to Window->show view->expressions then in Expressions window go to variables tab
there you will see your variables right click on any one of them you will see Show logical structure.
Untick the Array option from there and debug again you will see elementData,modCount and size varibles.click here for image
Related
Arrays in my debug view in eclipse are shown element-by-element downwards. This makes it difficult visually if I have too many arrays since I have to keep scrolling and cannot see all of them on a single screen.
Is there a way to see the array in a single line in the Variables section of the debug view in Eclipse?
You can use the below snippet to print in one line.
java.util.Arrays.toString(theArray);
There's no way (that I know of) of showing the array in a single line in the Variables View. I don't have eclipse installed in this PC but, as Kulbhushan said, you can try to execute the code
java.util.Arrays.toString(array);
in the Display View (to open it go to Window > Show View > Display).
While debugging Java code, Strings in the views "Variables" and "Expressions" show up only till a certain length, after which Eclipse shows "..."
Is there any way to inspect the entire string? (This eases the pain of adding logging statements for debugging everywhere)
In the Variables view you can right click on Details pane (the section where the string content is displayed) and select "Max Length..." popup menu. The same length applies to expression inspector popup and few other places.
In the Variables view you right-click on the variable and select Change value. If your variable is huge you have to wait a few minutes (in this case Eclipse doesn't respond to commands) but in the end Eclipse will show your variable entirely.
If you have a really long string, I use a different strategy: dump it to a file. I have a snippet of code I use in the Display view, which is evaluated to dump the data to a file. I use Commons IO, but you can do it with JDK only methods.
org.apache.commons.io.FileUtils.writeStringToFile(new java.io.File("<filename>"), <expression to evaluate>);
Naturally, you will need the Commons IO JAR in your classpath for that to work. If you don't, resort to JDK work.
The best way to view a String value from eclipse debug view is as below.
1) Switch to debug view in Eclipse
2) Select the desired variable in variable pane.
3) Right click on display area of variable pane where value is shown and click on Max Length. Enter the maximum char value in Configure Details Pane .
4) Cheers
When debugger reaches the point where you want the String value, just type a sysOut statement
System.out.println("The value is : \n " + query);
Select the above the statement, right click-> Execute
It will print the value on the console
For javascript based debugging on eclipse, "change value" method and "Max length" method both failed for me, adding the required object to watch(Expressions) and then Right Clicking the watched expression to select "Load Full Value" is the only solution that works for me, but even this inserts unwanted "\n" in the output.
Note - "Max length" must be set for the "Load Full Value" to work as it loads values till max length(default in eclipse is 10000). Refer above answer to see how to set Max length.
There is no "maxLength" in Eclipse Mars. And, the "change value" only works with "Variables", not "Expressions", so none of above works for me.
And, the expression are cut in the middle, not at the end. I guess they changed the default behaviour.
The only thing working for me, is to expand the expression name column's width, and click the expression to select it all to see the full length content.
Nothing from the above worked for me, moreover, some user interface elements in my Eclipse can not be found as described. I'm using STS 4.3.1.
The value I needed was really big, it is part of a huge JSON request. Workaround is to use an expression in Eclipse Debug Shell console and to output the substring of the whole value. Since you can see the partial value, inspect it and use the last few literals as the position to output the next chunk of the string. Repeat this approach until get what you need:
String result = new String(reallyBigByteArrayValue, "UTF-8");
result.substring(result.indexOf("some-unique-text"));
In Eclipse IDE 2020-09 it's "Pretty print to console" on right click.
From the console the copying is possible at full length.
Is it possible to evaluate a expression in Eclipse similar to IntelliJ. Where you can dynamically type code and the result will be displayed during debug?. I know it does something similar "Display" but you need to highlight code that has been written (so you cant write any new code unless you re-compile).
Perhaps there are plugins that i could use?. I have just started using eclipse
There is a Display view as well that can do exactly what you want. Go to Window > Show view > Display (or Other... if the Display view is not there. In the Display view, you can type any code you want during debug (content assist is available). The current objects and variables are also available to use. After you wrote your code, you have to highlight it, right click and select Execute or hit CTRL-U. You may play around with the other possible actions as well.
Besides that, you can also write in the source code during debug and evaluate it using Display as you mentioned, if you have the source for the class you are debugging.
1 - Type your expression inside a method that you are debugging
2 - Select that code
3 - Press CTRL + SHIFT + I
4 - Eclipse will evaluate your expression and show the results in a floating window
You can change variable values on the fly using the Debug perspective.
The top right corner of Eclipse should have the variables view from which you can select a variable name and change its value. You can also set conditional breakpoints by selecting the breakpoints view in the top right corner of Eclipse. Right-click on the breakpoint and select breakpoint properties. Check the conditional checkbox and write an expression that only when it evaluates as true does the program suspend during Debugging.
Change Variable Values during Debug
Conditional Breakpoints
Although Display View works; There are two ways else to evaluate an expression.
In the context of the debugging session, we can write and run custom code to evaluate possibilities. This is done in the Debug Shell. For example, if we need to cross-check the correctness of the sqrt functionality, we could do it in the Debug Shell. On the code, Right-click -> Inspect to see the value.
You can select an expression then open Context Menu -> Inspect or press CTRL + Shift + I, during debugging, the result will be displayed.
Select any expression in your code. Then right-click and select "Display" (or press the associated key-combination).
For completely new expressions, use the Display view. It's like a scrapbook for expressions. If the Display view is not visible, select Window > Show view > Display to add it. Then type any expression in the view, and do the same thing as for expressions in your code: select the expression, right-click and select "Display".
For expressions that you want to always see the value of, every time execution is halted, use the Expressions view instead.
Some of my variables are huge (include tables with so many rows). When I try to see the variables via variables view in Eclipse, it shows a part of it, not the all. So, I need to use system.out.println("myVariable"); to see, what my variable contains, and this not an effective way.
Is there a way to get over this? Or do you offer a better solution than sys.out.println?
The best I would suggest is to use the display view:
menu -> window -> show view -> debug ->display
inside the display view, type the variable name, right click and select display. Still if short, use the sysout statement there, and again, right click and select display.
Hope this helps.
In Variables window we have grid with list of variables and a field with variable signification below. Right click on this field => "Max Lenght ..."
When debugging a Java application in Eclipse JDT, values of some variables are displayed in the Variables view but not in tooltips when hovering over the variables in the editor.
The following screenshot illustrates the problem:
As you can see a tooltip with a variable value is shown for this. However no tooltip (or the one containing only declaration in case of Combined Hover) is shown for key while the Variables view shows values for both this and key.
I've tried Combined Hover and Variable Values in Java/Editors/Hovers as suggested here with a similar effect. The only difference is that Combined Hover shows declaration in a tooltip when Variable Values doesn't show a tooltip at all.
This turned out to be a bug in Eclipse reported here.
You seem to be working with an unsaved file (a star next to the file name). Try saving the file + rebuilding your project, then relaunch.