This question already has an answer here:
How to solve "NoClassDefFoundError"?
(1 answer)
Closed 6 years ago.
I'm trying to get an program that I coded to run properly. So far it will javac and java fine, however I get a NoClassDefFoundError.
This screenshot shows how I've javac, java the program, and the command prompt report.
As you can see I have 3 source files, and therefore 3 classes. PeriodicTable doesn't do anything related to the issue.
Inside of class Table I have...
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.json.JsonArray;
import javax.json.JsonObject;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Color;
import java.awt.Toolkit;
import java.awt.Dimension;
import java.io.IOException;
class Table {
//Predefining some global variables
DataBaseReader dbReader;
//some methods...
protected void showLayout() {
dbReader = new DataBaseReader();
//A few lines of code
try {
JsonArray elements = dbReader.readDataBase(); //Here it enters the DataBaseReader class through dbReader
//Some more code
} catch(IOException ioe) {
ioe.printStackTrace();
}
}
}
Here is my DataBaseReader class
import javax.json.Json;
import javax.json.JsonReader;
import javax.json.JsonObject;
import javax.json.JsonArray;
import java.io.FileReader;
import java.io.IOException;
public class DataBaseReader
{
public JsonArray readDataBase() throws IOException {
System.out.println("Check!"); //This check is reached
JsonReader reader = Json.createReader(new FileReader("C:/projects/PeriodicTable/Elements.JSON"));
System.out.println("Check!"); //This check is not reached
JsonObject jsonst = reader.readObject();
reader.close();
return jsonst.getJsonArray("Elements");
}
}
What versions, programs, etc am I using?
Java 8
Command Prompt
Notepad
javax.json-1.0.jar
To clearly state my question... Any ideas or explanations about what is causing this error?
i think you are missing javax.json-api-1.0.jar file
Related
I have the following class to perform PCA on a arff file. I have added the Weka jar to my project but I am still getting an error saying DataSource cannot be resolved and I don't know what to do to resolve it. Can anyone suggest what could be wrong?
package project;
import weka.core.Instances;
import weka.core.converters.ArffLoader;
import weka.core.converters.ConverterUtils;
import weka.core.converters.ConverterUtils.DataSource;
import weka.core.converters.TextDirectoryLoader;
import weka.gui.visualize.Plot2D;
import weka.gui.visualize.PlotData2D;
import weka.gui.visualize.VisualizePanel;
import java.awt.BorderLayout;
import java.io.File;
import java.util.ArrayList;
import javax.swing.JFrame;
import org.math.plot.FrameView;
import org.math.plot.Plot2DPanel;
import org.math.plot.PlotPanel;
import org.math.plot.plots.ScatterPlot;
import weka.attributeSelection.PrincipalComponents;
import weka.attributeSelection.Ranker;
public class PCA {
public static void main(String[] args) {
try {
// Load the Data.
DataSource source = new DataSource("../data/ingredients.arff");
Instances data = source.getDataSet();
// Perform PCA.
PrincipalComponents pca = new PrincipalComponents();
pca.setVarianceCovered(1.0);
//pca.setCenterData(true);
pca.setNormalize(true);
pca.setTransformBackToOriginal(false);
pca.buildEvaluator(data);
// Show transform data into eigenvector basis.
Instances transformedData = pca.transformedData();
System.out.println(transformedData);
} catch (Exception e) {
e.printStackTrace();
}
}
}
I am attempting to create a simple Java script which will connect to Rally, fetch all of the defects and return the defect details including the discussion as a Java object. The problem here is that the Discussion is returned as what I believe is a collection because only a URL is given. I am stuck on how to return the discussion for the defect as an object within the JSON rather than only another query which would have to be run separately (thousands of times I presume since we have thousands of defects).
Here is my code:
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.rallydev.rest.RallyRestApi;
import com.rallydev.rest.request.GetRequest;
import com.rallydev.rest.request.QueryRequest;
import com.rallydev.rest.request.UpdateRequest;
import com.rallydev.rest.response.QueryResponse;
import com.rallydev.rest.util.Fetch;
import com.rallydev.rest.util.QueryFilter;
import com.rallydev.rest.util.Ref;
import org.json.simple.JSONArray;
public class ExtractData{
public static void main(String[] args) throws URISyntaxException, IOException, NumberFormatException
{
RallyRestApi restApi = new RallyRestApi(new URI("https://rally1.rallydev.com"), "apiKeyHere");
restApi.setProxy(URI.create("http://usernameHere:passwordHere0#proxyHere:8080"));
restApi.setApplicationName("QueryExample");
//Will store all of the parsed defect data
JSONArray defectData = new JSONArray();
try{
QueryRequest defects = new QueryRequest("defect");
defects.setFetch(new Fetch("FormattedID","Discussion","Resolution"));
defects.setQueryFilter(new QueryFilter("Resolution","=","Configuration Change"));
defects.setPageSize(5000);
defects.setLimit(5000);
QueryResponse queryResponse = restApi.query(defects);
if(queryResponse.wasSuccessful()){
System.out.println(String.format("\nTotal results: %d",queryResponse.getTotalResultCount()));
for(JsonElement result: queryResponse.getResults()){
JsonObject defect = result.getAsJsonObject();
System.out.println(defect);
}
}else{
System.err.print("The following errors occured: ");
for(String err: queryResponse.getErrors()){
System.err.println("\t+err");
}
}
}finally{
restApi.close();
}
}
}
Here is an example of what I am getting when I attempt this:
{"_rallyAPIMajor":"2","_rallyAPIMinor":"0","_ref":"https://rally1.rallydev.com/slm/webservice/v2.0/defect/30023232168","_refObjectUUID":"cea42323c2f-d276-4078-92cc-6fc32323ae","_objectVersion":"6","_refObjectName":"Example defect name","Discussion":{"_rallyAPIMajor":"2","_rallyAPIMinor":"0","_ref":"https://rally1.rallydev.com/slm/webservice/v2.0/Defect/32323912168/Discussion","_type":"ConversationPost","Count":0},"FormattedID":"DE332322","Resolution":"Configuration Change","Summary":{"Discussion":{"Count":0}},"_type":"Defect"}
As you can see the discussion is being returned as a URL rather than fetching the actual discussion. As this query will be used at runtime I'd prefer the entire object.
Unfortunately there is no way to get all of that data in one request- you'll have to load the Discussion collection for each defect you read. Also of note, the max page size is 2000.
This isn't exactly the same as what you're trying to do, but this example shows loading child stories much like you'd load discussions...
https://github.com/RallyCommunity/rally-java-rest-apps/blob/master/GetChildStories.java#L37
Please help me, I am only still a student, I've still much to learn. I've searched everywhere and I still can't find any solution to this error so I've resorted to asking here at Stack Overflow...
My imports:
import javax.sql.rowset.JdbcRowSet;
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;
import java.lang.Throwable.*;
This is where it gets the error:
public static void info() {
try {
Class.forName(JDBC_DRIVER);
rows = new JdbcRowSetImpl(); // This is where the error is
rows.setUrl(DB_URL);
rows.setUsername(DB_USER);
rows.setPassword(DB_PASS);
} catch (/*SQLException | */ClassNotFoundException e) {
e.printStackTrace();
}
Try to import the following library:
import com.sun.rowset.JdbcRowSetImpl;
Add the above line of code to the import section of your class
I am trying to train en-ner-location.bin file using opennlp in java The thing is i got the training text file in the following format
<START:location> Fontana <END>
<START:location> Palo Verde <END>
<START:location> Picacho <END>
and i trained the file using the following code
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
import java.util.Collections;
import opennlp.tools.namefind.NameFinderME;
import opennlp.tools.namefind.NameSample;
import opennlp.tools.namefind.NameSampleDataStream;
import opennlp.tools.namefind.TokenNameFinderModel;
import opennlp.tools.tokenize.Tokenizer;
import opennlp.tools.tokenize.TokenizerME;
import opennlp.tools.tokenize.TokenizerModel;
import opennlp.tools.util.ObjectStream;
import opennlp.tools.util.PlainTextByLineStream;
import opennlp.tools.util.Span;
public class TrainNames {
#SuppressWarnings("deprecation")
public void TrainNames() throws IOException{
File fileTrainer=new File("citytrain.txt");
File output=new File("en-ner-location.bin");
ObjectStream<String> lineStream = new PlainTextByLineStream(new FileInputStream(fileTrainer), "UTF-8");
ObjectStream<NameSample> sampleStream = new NameSampleDataStream(lineStream);
System.out.println("lineStream = " + lineStream);
TokenNameFinderModel model = NameFinderME.train("en", "location", sampleStream, Collections.<String, Object>emptyMap(), 1, 0);
BufferedOutputStream modelOut = null;
try {
modelOut = new BufferedOutputStream(new FileOutputStream(output));
model.serialize(modelOut);
} finally {
if (modelOut != null)
modelOut.close();
}
}
}
I got no errors or warnings but when i try to get a city name from a string like this cnt="John is planning to specialize in Electrical Engineering in UC Fontana and pursue a career with IBM."; It returns the whole string
anybody could tell me why...??
Welcome to SO! Looks like you need more context around each location annotation. I believe right now openNLP thinks you are training it to find words (any word) because your training data has only one word. You need to annotate locations within whole sentences and you will need at least a few hundred samples to start seeing good results.
See this answer as well:
How I train an Named Entity Recognizer identifier in OpenNLP?
I am using xuggler to play video files from my code and the following is a snippet from the main code:
This snippet produces an error :
//The window we'll draw the video on.
private static VideoImage mScreen = null;
private static void updateJavaWindow(BufferedImage javaImage)
{
mScreen.setImage(javaImage);
}
// Opens a Swing window on screen.
private static void openJavaWindow()
{
mScreen = new VideoImage();
}
The error that i get is : cannot find symbol : class VideoImage
The header files used are :
import java.awt.image.BufferedImage;
import com.xuggle.xuggler.Global;
import com.xuggle.xuggler.IContainer;
import com.xuggle.xuggler.IPacket;
import com.xuggle.xuggler.IPixelFormat;
import com.xuggle.xuggler.IStream;
import com.xuggle.xuggler.IStreamCoder;
import com.xuggle.xuggler.ICodec;
import com.xuggle.xuggler.IVideoPicture;
import com.xuggle.xuggler.IVideoResampler;
import com.xuggle.xuggler.Utils;
Am i missing in some import statement ? If not , here are the libraries i am using apart from JDK :
What is the reason i am getting that error ?
VideoImage Javadoc
You are not importing the right class.
com.xuggle.xuggler.demos.VideoImage
It seems like you are already using an IDE. It should automatically tell you what import you are missing if the correct library is in the build path.
You need to import the VideoImage class.