Class strange error - java

I am using Eclipse Spring edition (STS) and I am getting a strange error in one of the classes in my project:
can not implement the missing methods, either due to compile errors can not implement the missing methods, either due to compile errors
The class causing this error name is ItemDAO, and it implements interface IItemDAO, and I am 100% sure that there are no un-implemented methods, but Eclipse insists that there are some un-implemented methods, and when I click on the class name and select implement un-implemented methods I get the above error.
Can someone please tell me what I am doing wrong here and how to fix this problem?
Thanks for your time

I Just had the issue and fixed it by cleaning the project.

What the messages says is that since you have compile errors, Eclipse cannot perform the auto-implement action.
The compilation errors are most probably, either in ItemDAO class or IItemDAO interface. Fix them first and then retry the auto-implement action.

The error message states that you have not implemented all the
methods in IItemDAO.
While you try to order eclipse to implement it automatically, it can't be done, because there are compilation errors in the methods (which are still to be implemented or unimplemented) in IItemDAO

Instead of using the jre, use jdk. It will resolve your problem.

I had the same issue.
Here is the error message :
cannot implement the missing methods, either due to compile errors or the project build path does not resolve all dependency
The issue was resolved after cleaning the project as suggested

Go to Source -> cleanup -> besides there is a button configure click on it -> check Enable project specific settings -> apply and close

I have faced the problem, at my situation (I use Maven). I want use struts ServletRequestAware, and it need the servlet-api.jar. So you need to add Tomcat runtimes.
Go to your project, right click->Properties->Project Facets->Runtimes-> add Tomcat.
That`s all.

Related

error occurred "java: cannot access java.util.function.Function class file for java.util.function.Function not found " in selenium

I am having the above issue once am running the code. I have changed my language level into 8 and added maven properties into the POM file. But still having this issue. Please help me to resolve this.
Yes as like above comment it's quite difficult to solve problem without any error log or code so if possible please add it.
Else where as per my experience i thought that it's occurred in case where your JDK dependency not bind properly with your project.
In such case you're not able to use that library inside your project. For that go inside "Project settings" inside your IDE and check dependency bind properly(like following image) or not if not then do it first.

IntelliJ: Disable warnings/errors for a single module

I've recently migrated to IntelliJ and need to solve a particular problem: I have a project that has numerous modules; one of these modules is purely for testing and contains a number of errors:
.
I'd like to suppress all warnings/errors/inspections on NNGINETest in this screenshot. Is there a way to configure the project to do that? I found this answer: How do I disable some inspections for modules in IntelliJ IDEA? but I'm not quite sure it's for the same thing. On top of that, the answer was a bit unclear to me and I wasn't able to understand all of the steps because of how new and unfamiliar with IntelliJ that I am.
If someone could please thoroughly explain to me how to solve this problem, I would be grateful.
Since you have errors in NNGINETest, I suppose you don't need to run it. So I would suggest marking the src folder under NNGINETest as excluded. like:
I tried to expand Eric's answer but it was rejected for arbitrary reasons, so I'm writing my own to try and clarify some more for anyone else that runs into this problem since I hate bureaucracy. Adding it as an answer will allow me to provide some visual aids:
NNGINETest has errors that are reported in building. Eric's answer is correct in that we can exclude it, but the problem is that the console is still spammed with error reports upon building when I right clicked the project and marked it for exluding that way. I fixed it by excluding it via the menu in File -> Settings -> Build, Execution, Deployment -> Compiler -> Excludes
You'll want to probably also make sure that the "Recusively" checkboxes are checked for modules you want to exclude.
I don't really know what the difference is here between this and using the right click menu option (I couldn't find anything in the IntelliJ manual about it either but maybe someone can provide a link in the comments), but this successfully prevented NNGINETest from littering the console during building:
Additionally, using the Excludes menu rather than the directory marking for the module allows it to still appear in the Project module list rather than disappearing. An "x" will appear by excluded folders. This is pretty useful in my opinion:
Hope this helps!

Android Studio 3.1.3 - Unresolved reference: R - Kotlin

I am new to kotlin, i have converted some code from java but it seems like there's something wrong, The R in findViewById(R.id.my_id) is highlighted in red and it shows this message : "Unresolved reference: R".. I've been looking for a solution but i seem not to figure it out, So what should i do?
Here's a screenshot :
The issue can be caused by many factors,
as mentioned by martomstom in this Answer the issue is sometimes caused by com.android.tools.build:gradle version, changing it's version to a more stable one would solve the problem: for example: com.android.tools.build:gradle:3.4.0-alpha02 with com.android.tools.build:gradle:3.2.1
Also, having libraries from the same group, but with different versions may cause the problem or even more runtime errors. use the exclude group method like the following : implementation('com.squareup.picasso:picasso:2.71828') { exclude(group: 'com.android.support') } in this case, picasso library uses android.support components, the android library version used in picasso is different than the one you're currently using in your app, so in order to solve this issue, we have to exclude it completely from its sub library and class groups.
It can also happen by the mismatch of resources and code, including this importation line in your activity may solve the problem too : import com.package.name.R
Sometimes it can happen because of the IDE, performances or memory.. Cleaning the project from time to time may save you some time, on Android Studio it would be something like this : Build -> Clean Project / Rebuild Project - Cleaning IDE cash also helps with performance and memory, on Android Studio it would look like this : File-> Invalidate Chases/ Restart -> Invalidate Cashes and Restart
I noticed that this problem happens to me the most of the time when importing new resources, Using prohibited characters in their names would fire the error, such as . , , - , UpperCase or special Letters
And as a suggestion , if you're using Kotlin, i really recommend using Kotlin extensions in your activity such as : import kotlinx.android.synthetic.main.activity_page.* or if you're using a custom view : kotlinx.android.synthetic.main.view_layout.view.*
after that, in onCreat() method of an activity , you'll only have to call the id, for example : my_edit_text_ID.text = "Kotlin Dbest!", or from a custom view : mCostumView.my_edit_text_ID.text = "Kotlin Dbest!"
EDIT :
I have faced this issue againe and the problem was the '' R '' library was imported from 2 different sources :
com.android.R
com.example.package.R
You must only import the '' R '' library with your application package name,
in this case com.example.package.R
Sometimes the library is not imported at all, to import it, click on the
unresolved reference R and press Alt + Enter
EDIT:
As tobltobs mentioned in the comments section: " Most of the time the problem is caused by another error which prevents the build system from creating generated sources. To find the root cause look at the gradle log (the "toggle view" icon below of the green hammer in the Build output) and look for errors unrelated to R or BuildConfig (also generated). If there is no other error left and the problem with R persists then maybe something of this list might help. "
EDIT:
As Patrick Beagan mentioned, Kotlin extensions are now deprecated - I'd advise using ViewBinding instead
I used com.android.tools.build:gradle:3.3.0-alpha13 and had the same issue. Changing to stable Version 3.2.1 solved this problem for me.
So this is a misleading error.
The fastest way to get to the root cause is to run:
bash gradlew assembleDebug --debug
then scroll up and look for the real error happening.
However, if it still doesn't seem like you have the answer you are looking for, then read on.
I'm going to explain the 30,000 foot view of what is happening. This is not EXACT order or EXACT flow, it is just pretty damn close ;) so if you know more then I do of the exact order and care to make corrections with links, feel free I won't stop ya :).
The Process
The R file is generated code.
There is an order to the generation.
Gradle will do it's magic, pull it's dependencies and kick off it's
warning and error tree first,
then Android converts all Kotlin to Java behind the scenes. Yup that's
right, our beloved Kotlin still has to be Java to compile for our
beloved ART virtual machine.
Then it runs through and does the adapters that you have created for
JVM Statics and a few other tasks.
Next up it compiles all the xml databinding files first to create the
generated databinding files.
If everything succeeds it moves on to processing the assets and
resources. Which creates pointers or IDs for each resource that you
reference in code. Next it will run through and begin compiling the
code and packaging process after that.
Pretty straight forward process, but here in lies the problem.
The misleading Error
If any step fails before the R generation is complete, then the R does not get generated. Sometimes a simple rebuild is all you need to do, sometimes a simple File->Invalidate Cache and Restart is all you need. However, more often than not you have a code issue in your gradle, your xml, your databinding or your adapters that are preventing the compiler from even reaching the R generation stage.
So the next question is
"Well shoot, how do we troubleshoot it if the errors are worthless or
non-existent".
Well first let's talk about the many ways these errors present themselves.
Duplicate Databinding class found
xml Binding Error at line #
Couldn't find matching signature of bind:customAdapterMethod
Can't find R file of the correct project, only shows import options for sub modules or incorrect namespace R files.
Couldn't find DataBindingUtility or DataBinding for activity/fragment
And many other various ways as well, too many to list them all
Next, let's talk about potential candidates causing the problem. As there are sooo many lol.
Gradle Syncing issues
Bad versions of Gradle or Tools, you may have gone too far forward in your last gradle file modification. Try stepping back one version and "invalidate cache and restart" if that fixed it, great, if not, read on.
Caching Issues (File->Restart and Invalidate Cache)
xml elements with wrong namespace
xml elements with bad IDs or references IDs out of order (i.e. you say align to right of an element that is lower in the xml document then the sibling element that is trying to reference it)
xml data binding issues referencing namespace or member that doesn't exist or is not typed correctly
xml data binding issues in non-auto-filled spots like custom attributes using adapters as those are harder to spot. i.e. bind:myCustomMethod=#"myObject.mistypedProperty()"
JVM Static adapters with issues or duplicated signatures
Duplicated or bad character in the Strings or Dimens file or any other xml file for that matter
Private variable marked for #Binding without properties to access it
Member variable marked for #Binding that matches a parent class method causing duplications that manifests itself in almost impossible errors
Mismatch of types like using an adapter that takes (Int) but you are passing (Int?) via data binding and it isn't recognized with JVM Statics until compile time
You selected IMPORT on a popup to import R file of a sub module instead of the application file
Having bindable members in a child or parent class, but not giving fully qualified namespace to class cast in the XML usage of the parent or child class. As the databinding compiler is not smart enough to realize the variable provided for class Foo is also parentFoo baseclass, so you have to qualify it as android:text="#((com.path.parentFoo)foo).parentMethod"
Having a method name in a class, that matches a "generated property from #Binding member variable" i.e. firstName as a variable, but then having a method called getFirstName in a parent or child class, because you are now matching a method name that will get auto generated, thus causing dataBindingUtility duplication class errors.
There are more causes, but this should give you a series of places to look, but the list can go on and on seriously.
Unfortunately this happens a lot in bleeding edge technologies where the UI tools are not up to speed with the terminal based tools yet. So I suggest you run from the project root in a terminal with
bash gradlew assembleDebug --debug
When it fails, and it will. Start scrolling up through the logs until you find the red where you see what is actually failing and preventing the next stage from occurring.
You will find this especially useful when you start dealing with databinding.
TIP:
When you start dealing with databinding, make sure you compile and run often because the goal is to recognize right away before doing other files to make sure you didn't break generation and make your life MUCH easier to know code you just added caused the issue before getting too far.
Times to compile and run to confirm no issues before moving on.
If you add a few JVM statics compile and run
If you add variables to your XML to use
If you bind to properties of your model in 1 file
If you add a binding to a JVMStatic
If you add bindable members or properties to an model
If you refactor moving observable member variables or properties into children or base classes
Any other xml or binding related elements that can effect the generated code.
Like I mentioned above, the reason is to avoid getting so many changes, that it becomes a troubleshooting nightmare to find a generic vague, horrible error related to generated databinding code. I'm sure the tools will improve, but for now, do yourself a favor and compile and run often when changing Databinding related items.
Happy Coding
Use gradle commands.
In Android Studio, on the right menu:
Gradle -> :app -> Tasks -> build -> clean.
After that, Gradle -> :app -> Tasks -> build -> build
I had wrong import statement import android.R instead of import my.project.package.R. Fixing it solved the problem
I had the same problem, and I tried not to downgrade from gradle version 3.3 to gradle version 3.2.1. Instead I updated Android Studio to version 3.3, which made the trick for me ;-)
This worked for me. How much work it is depends on how big your project is. I started a new project, created the required modules (XML, Kotlin, colors, strings, etc.), then copied the code into the modules in the new project from the modules in the old project. Copying XML saves a lot of time compared to recreating the UI. All in all, it take a little while, but I have spent much more time tring to fix the unresolved reference error without it.
TRY THIS
Go to the content_main.xml file and there you need to change the
android:id="#+id/??????"> line of code to whatever id you have given to your file.
Replace question mark ?????? with the related file id name.(IF you dont know the id go to the design tab on the bottom and click on the related Asset.
On the right side below attributes, you can find the ID you have given to it.
If it is blank you can freshly name it and Android Studio will write the code.
Then restart Android Studio. Hope this will help. Happy coding.
I believe that I came across the real answer (though by accident).
I also, as the OP had my KT file fail to location R. as well as other classes that happen to be in java. What I noticed was that there was a case difference I the filenames. Once I corrected the import statements to match the case of the package (aka, folder) the errors resolved.
I had the same problem with R reference too.
Finally Android Studio 3.3 has been released and using 'com.android.tools.build:gradle:3.3.0' the problem has been fixed!
I update Android Studio to version 3.3.1 and solved this problem.
Downgrading gradle version worked for me.
I changed :
Gradle version from : 4.10.4 to 4.4.1
and Gradle Plugin version from : 3.3.1 to 3.1.3
If your are experiencing this issue in Kotlin because you cannot reference the elements of the xml layout by ids. (e.g. R.id.adView) then try removing the line import android.R from your kotlin file.
For me it was because I had created a new package and R wasn't available until I imported it from the package above
I faced the same issue. I restarted my Android Studio, invalidate caches, Sync Gradle but nothing was working. Then I looked into my file and there are 2 imports of my R. 1 import was related to my application package and the other was related to Android.
import com.example.myApp.R
import android.R // This import was added accidentally during the build.
Removing second import related to android solved this issue.
I had an issue because of this import:
import android.os.Build.VERSION_CODES.*
In the latest version it contains R
I had same problem while using auto-manifest plugin. Adding AndroidManifest.xml explicitly solved the problem to me.
I used to File --> Invalidate Caches... and issue resolved.
Just restarting Android Studio solved it for me.
I also had this problem, Gradle Sync, and Invalidate Cache, and Restarting Android Studio Didn't help. Upgrading and Downgrading Gradle were also not helpful.
What worked for me is: Make Project (Ctrl + F9) and then try to run the project.
I solved this error by following Android Studio's lint tools to upgrade the version of a dependency in the project-level gradle file. In this case, I upgraded androidx.navigation:navigation-safe-args-gradle-plugin from 2.3.2 to 2.5.2 (latest version), then synced the project.
Here is the solution,
File->Project Structure->Project, select Android Gradle Plugin Version as 3.2.1 from the drop-down. then click apply.

Importing a project into Eclipse and deploy it in your local

I have a project in Accurev for which I created a workspace. I did File > Import > Existing Projects into Workspace. After the import, the first thing that I have done is Configure Build path (Project>properties>Java Build Path). Still, I can find a lot of errors. I'm new to Java and I'm searching the Java errors in google and fixing them. Please suggest, How can I solve the similar errors for multiple files.
For Example,
The Empty block should be documented (I have it in 3 files)
The parameter customerExpression should not be assigned ( Multiple files )
The import java.util.List is never used ( Multiple files ). There are some other imports which were used inside the company are never used.
Apart from Java Problems, I do have
Classpath Dependency Validator Message
EJB Validator Message
HTML, JSP Problems etc which I feel can be solved once I solve Java Problems. I was told that Java problems are important. COrrect me if I'm wrong.
Please suggest.
Thanks
Like #Carlos Heuberger said these are seems like warnings not errors they won't cause any problem for your project to run. People usually don't care that much of warnings.
If you want to get rid of those warnings eclipse have quick fix actions for some of them. To do that head one of the warnings and right click then select quick fix. This should pop out a screen which summarize the action that eclipse will take.
Or you can simply hide them.
If you want to hide all the validation warnings go Window>Preferences>Validation then click Disable All button. This will disable all validation messages in your workspace.
For java warnings go through Windows>Preferences>Java>Compiler>Errors/Warnings and change the warning options according to your preferences. In my workspace under the Code Style section Undocumented empty block is setted to ignore so i don't get that warning in my workspace unlike yours.
Hope that helps.

Implementing Eclipse WorkbenchAdvisor class for a eclipse plugin project

I am writing an eclipse plugin and I want to implement a "expiration checker" to disable my plugin once a certain date is reached.
I understand that in order to disable the bundle, I need to turn it into UNINSTALL state (FYI - I got this from here: http://www.eclipse.org/forums/index.php/t/210006/). Furthermore, I will need to do this in preStartup() by implementing the WorkbenchAdvisor class (from org.eclipse.ui.application.WorkbenchAdvisor)
I found this answer which has contains everything I need to know (https://stackoverflow.com/a/11726335/2851950) EXCEPT I couldn't find IApplication or WorkbenchAdvisor under my plugin.xml's dependencies page.
Do I need install additional plugins from somewhere? What I am missing here? Thanks

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