I have just started learning java, so struggling in very basics. The problem i am facing currently is "cannot find symbol : class Ques". I have resolved this issue when i was accessing package from parent directory through CLASSPATH export. Now problem is i am trying to access sub-directory from sub-driectroy like this:
family.of.adam(has)/
father.java
WifeOne(sub-direc)/wifeone.java,ChildFromWifeOne.java
WifeTwo(sub-direc)/wifetwo.java,ChildFromWifeTwo.java
Now what i am trying to do is from wifetwo.java i am accessing wifeone.java. I have tried importing (wifeone)like this:
import family.of.adam.WifeOne.*;
import WifeOne.*;
In both cases it failed to import and same error occured which i mentioned above.
I have also tried solution provided in this Question but this effects classpath of WifeOne this is what i think because when i -cp method it starts showing errors related to wifeone.
I am using normal texteditor, compiling through terminal and using mac. Kindly brief me what mistake i am doing.
Assume src is your base folder(place you compile and run the program).
src/family/of/adam/FirstWife.java
if so you need to define the package startmetn the fist line of the FirstWife.java file.
package family.of.adam;
Then,If the second java file in the,
src/Main.java
In Main.java file you need to define the import statement for user the FirstWife.java class.
import family.of.adam.FirstWife;
Related
So, i am running a java project which have many library that are available in the current working directory but VS code seems to not recognize these library and giving out error "The import ###### cannot be resolved" ex: The import org.apache.pdfbox.pdmodel.PDDocument cannot be resolved"
here is the image that might help you to know more about it
This is the package that i am working on :
Here the org/apache is the library contain the class file that are need to be imported and FileArrangement.java is the file having the import statements
Error i have been receiving
this is what VS code is been showing
i really need your help because i really don't have any idea how to correct this
I have checked other projects and they are also showing the same result although the import statements for java classes like . java.util.ArrayList doesn't show any kind of error and i have tried to clean java in VS code it also didn't work
i just need to correct this error of VS code to import the classes that i need
No error on java.util package
Putting the libraries in your current working directory does not work for Java, you need to add them to the classpath.
If you're using maven, that manages the classpath for you.
If not, you can manage it in VS Code by executing the Java: Configure Classpath command from the Command Palette (Ctrl+Shift+P).
You can add dependencies via Referenced libraries under the JAVA PROJECTS panel.
Or use java.project.referencedLibraries setting in settings.json.
For example:
"java.project.referencedLibraries": [
"library/**/*.jar",
"/home/username/lib/foo.jar"
]
Details can be found in configure-classpath and manage-dependencies.
I'm writing a Java class that will be used to send PDUs across a network- to do this, I am following the tutorial at: Tutorial
In the example, the line:
double lla[] = CoordinateConversions.xyzToLatLonDegrees(c);
appears towards the end of the class, and I see that CoordinateConversions has been imported with the line:
import edu.nps.moves.disutil.CoordinateConversions;
I have tried using the xyzToLatLonDegrees(); method in the class that I am writing- calling it in the same way as is done in the example. However, for some reason, I get a compile error that says:
CoordinateConversions cannot be resolved
on the line where I'm trying to use it, and
The import edu.nps.moves.disutil.CoordinateConversions cannot be resolved
on the line where I am importing it.
Does anyone know why this is, and how I can fix the import, so that I can use the xyzToLatLonDegrees() method?
You need to have the CoordinateConversions class on your classpath. Either by obtaining the source and dropping it into your project (possibly adjusting package names, and only if the license allows), or by finding a JAR containing that class and adding it to your build path in your IDE.
You probably need to download the Java files from here.
I'm trying to compile a small test program I have written for a raspberry pi.
The program makes use of the Pi4J library to control the piface add-on board.
What I have done so far is based on the following tutorial: http://www.savagehomeautomation.com/piface
While I can get the above example program to compile within my IDE after setting up the class paths I get compile errors with the one I have made and as far as I can tell the imports are set up in the same way.
It says that each of the following packages does not exist:
import java.io.IOException;
import com.pi4j.component.switches.SwitchListener;
import com.pi4j.component.switches.SwitchState;
import com.pi4j.component.switches.SwitchStateChangeEvent;
import com.pi4j.device.piface.PiFace;
import com.pi4j.device.piface.PiFaceLed;
import com.pi4j.device.piface.PiFaceRelay;
import com.pi4j.device.piface.PiFaceSwitch;
import com.pi4j.device.piface.impl.PiFaceDevice;
import com.pi4j.wiringpi.Spi;
I'm assuming that my problem is relatively simple but I don't really understand how import statements work and it's quite vague topic to search about. I have included some file paths if that helps.
This is where my project resides:
/home/pi/JBerries/relay
and this is where the pi4j library is:
/opt/pi4j
I hope the following image provides some of the information requested, note that the class paths are already set up:
You need to set the CLASSPATH environment variable to /opt/pi4j or the jar file therein. WIthout this the compiler is unable to know where your libary is located and will give you the errors you describe.
If you're using a project in JBerries you need to configure the classpath for the project - the screenshot shows the classpath for single-file compilations only. To edit the project config right-click the root node in the project window and select properties.
OK, like many of the package compiling issues out there I have not found one like this out of the 12 hours I've spent searching..
Basically I have the normal setup :
My Directories are as follows: JavaCSVReader/FRC_API
My Source files are setup as this:
JavaCSVReader/CSVFile.java
JavaCSVReader/FRC_API/RobotConfig.java
(that is CSVFile.java is located in JavaCSVReader and same for RobotConfig.java)
CSVFile.java contains the lines:
package JavaCSVReader;
import JavaCSVReader.FRC_API.*;
...
RobotConfig.java contains the lines:
package JavaCSVReader.FRC_API;
import JavaCSVReader.CSVFile;
...
Both files compile fine without the lines above.
The error is thus: I receive
"cannot find symbol... class: CSVFile location: JavaCSVReader"
when I try to compile the RobotConfig.java.
I also receive the
"package does not exist: JavaCSVReader.FRC_API" error when compiling CSVSFile.java
my
CLASSPATH=/home/src/JavaCSVReader/:.:..
(I am using linux)
Your classpath setting is wrong. You should set it to
/home/src/
The compiler will take classpath as the "base" directory in order to find packages defined in the source.
it's a classpath issue.
How do you configure java environment variables?
You'd better check on it.
is your package JavaCSVReader.FRC_API; or JavaCSVReader ?
I am trying to call a python method in java, similar functionality as Unresolved import org.python / working with jython and java?
However, I am using ant to compile and run my files. using import org.python.util will give me this error
package org.python.util does not exist
I can see that python.org.util exists in jython-2.5.0.jar.
So, here is the class path I have in my build.xml ant file:
classpath="${java.class.path}:./jgrapht/lib/jgrapht-jdk1.5.jar:\
./jgrapht/lib/jgraph.jar:./jgraphx/lib/jgraphx.jar:\
./jython/lib/jython-2.5.0.jar:./colt/lib/colt.jar:."
and I also I added the path to jython jar files to my class path. i.e. looks like echo $path gives me all the required paths. Is there anything missing here that I am not aware of?
Try this to make all classes in the package available:
import org.python.util.*;
Or this to include a particular class:
import org.python.util.TemplateAntTask;
EDIT: Also, looks like there is an extra slash after jython-2.5.0.jar in your classpath.