I've been trying to create my own FTP client written in Java. I wrote one ages ago in C#, so I would like to try in Java. I created a user library for apache commons and added it to my build path. The problem is that when typing the import statement it doesn't recognise it. It finds a error at org, saying "import org cannot be resolved".
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
I am using eclipse as my IDE.
Here two screenshots showing the error:
The following line is probably missing in the module-info.java file:
requires org.apache.commons.lang3;
and in the Java Build Path the Classpath contains the broken (as you can see from the red error mark) item apache-commons-lang by mistake: select it and click Remove.
Since Java 9, modules can be specified, but this requires a correct module-info.java file and the libraries must be added to the Modulepath instead of to the Classpath. Without the module-info.java file it would be easier. Therefore, perhaps the simpler solution would be to delete module-info.java file.
In addition, the *-source.jar should be as Source attachment a child of the main JAR and the *-javadoc.jar is not needed with the source (but if, then as Javadoc location child of the main JAR).
Hint: If an error or a warning is shown with a light bulb, go to the line and click Ctrl+1 and Eclipse will suggest solutions for that problem.
Related
I'm new to the whole programming stuff but here's my problem:
I used to add my JUnit test cases in Eclipse by right clicking on the project, and just add New > JUnit Test Case.
Currently, I am not able to implement any test methods because Eclipse tells me on the line
import static org.junit.jupiter.api.Assertions.*;
the error message
The type org.junit.jupiter.api.Assertions is not accessible.
Error I get in the IDE:
I tried the following:
Reinstalling Eclipse, using a fresh workplace.
Adding the JUnit to Build path
Nothing helped.
It worked and works in older projects just fine.
Here is how the Package Explorer looks:
What am I missing?
You use the Java Platform Module System (JPMS) by having a module-info.java file in the default package probably without the required requires <module>; statement. JPMS was introduced in Java 9.
Do one of the following:
Delete the module-info.java file (if needed, you can recreate it via right-clicking the project folder and choosing Configure > Create module-info.java)
In module-info.java add the corresponding requires statement, e.g. by going to the line with the import statement and using the corresponding Quick Fix (Ctrl+1)
I have just recently started using Eclipse and am running into problems trying to install external libraries. Following online tutorials, I add the .jar file to the classpath and I see it in the referenced libraries folder. Despite this, when trying to import, I get the error:
The package org.apache.commons is not accessible
For reference, I am trying to install the apache math commons library.
Your code probably has two issues.
First, the import statement is wrong since in Java you cannot add a package itself, but all classes of a package as follows (note .*; at the end):
import org.apache.commons.math4.linear.*;
or a specific class, e.g.
import org.apache.commons.math4.linear.FieldMatrix;
Second, you use the Java Platform Module System (JPMS) by having a module-info.java file in the default package probably without the required requires <module>; statement. JPMS was introduced in Java 9 and you have Java 12.
Do one of the following:
Delete the module-info.java file (if needed, you can recreate it via right-clicking the project folder and choosing Configure > Create module-info.java)
In module-info.java add the corresponding requires statement, e.g. by going to the line with the import statement and using the corresponding Quick Fix (Ctrl+1)
I am trying to determine whether a set of strings, from an English sentence, are all words from the WordNet dictionary. I put the JARs in a folder in my project in eclipse.
I've downloaded the binary release of extJWNL and put the JARs in a folder called lib.
I also added these jar files to the class path and the module path using Right Click > Build Path > Configure Build Path:
I used the following code to try to import dictionary
import net.sf.extjwnl.dictionary;
This error is shown on the import statement
The package net.sf.extjwnl.dictionary is accessible from more than one module:
<unnamed>, extjwnl
I thought that this error was showing up because it was a package, not a class/type. But adding a new class and trying to change the package doesn't show this new package, namely WORDNET_JARS, just the default package.
Why is this error being returned and what do I need to do to get rid of the error and import the wordnet packages?
Platforms
I am using Eclipse IDE, and write all this code in Java. The API I am trying to import is the WordNet API.
Edit (8/21/2019)
By removing the module path, it gives a new error:
Only a type can be imported. net.sf.extjwnl.dictionary resolves to a package
I'm surprised it was this easy:
Instead of
import net.sf.extjwnl.dictionary
I had to do
import net.sf.extjwnl.dictionary.*
to get all the types. The only other thing that had to be done had already been done where I add the JARs to the class path
I know I am asking the very popular question. But I can not find the solution to the problem. I have a sandbox to which I added a code of the unit test MulticurveBuildingDiscountingDiscountAUDTest.java file and commented it.
Then I added the main method and I could successfully run the program (print something in a console).
Finally, I uncommented the code of the MulticurveBuildingDiscountingDiscountAUDTest.java file and I saw the following error:
The import com.opengamma.analytics.financial.instrument.index.GeneratorSwapFixedONMaster cannot be resolved.
And further in the code:
GeneratorSwapFixedONMaster cannot be resolved
I know that this import is located in the og-analytics src/test/java location, which I believe is not listed anywhere in the build path. I believe the problem is with a build path options and specially with classes like GeneratorSwapFixedONMaster which were created specially for tests. I have been playing around with cleaning, rebuilding projects, reinstalling and as a result updating the JRE. I have visited these Import *** cannot be resolved [duplicate] and these Eclipse error: “The import XXX cannot be resolved” questions.
Do you know what shall I do to cure the following error?
I have many problems with other imports from the original MulticurveBuildingDiscountingDiscountAUDTest.java file as well.
Update: #1 is a location of my file. #2 is the location of classes this project uses. The MulticurveBuildingDiscountingDiscountAUDTest.java file is taken from the src/test/java
Update 2: one may see that in Libraries I have included all the dependencies I might need (at least I do not know what else to add). The Maven Dependencies contains the hole og-analytics package:
You included the source (src) folder og-analytics/src/main/java which contains the *.java files instead of the classes (bin or classes) folder with the *.class files (in your case, probably og-analytics/target/classes).
But instead using Add Class Folder... you should add the project og-analytics in the tab Projects. Or even better, in the Maven pom.xml file add the dependency to the project og-analytics like you did for og-util.
I know that this import is located in the og-analytics src/test/java location, which I believe is not listed anywhere in the build path.
Perfectly explains your problem. In order to import any class, you must either have the source in your build path, or some directory that contains a compiled version of that class. It is that simply.
The answer is: get clear on your project setup. If you intend to use classes from somewhere, you have to make them available somehow. Otherwise it will not work. In your case: if your tests want to make use a certain thing - then you should probably add that "thing" to your test project (you should avoid putting test-only stuff to your "product" projects).
That is all there is to this.
hi all
i use the javazoom.jl.player.Player package but it is says The import javazoom cannot be resolved. i am using eclipse and doing Android project. i clean the project still the same error is shown. please correct me.
If eclipse can't resolve a package fragment of an import statement, then it tells you (with that error), that there is no library on the classpath that contains a class from that package (or from a package whose name starts with the missing part).
An easy way for standard java/eclipse:
create a folder lib in your projects root directory (with the eclipse workbench!)
copy and paste the jar into that folder
right-click the copied jar and select "add to build path".
This should eliminate the compiler errors immediately.
(Previous part of the answer)
Taking the error message literally, it looks like you have a line of code like that:
import javazoom;
This would be wrong, because we don't import packages but classes from a package. To import all classes from the javazoom package, we'd say:
import javazoom.*;
You should download the .jar of jLayer ( http://www.javazoom.net/javalayer/sources.html )
And add into classpath in the way Andreas_D told you.