The type org.jfree.data.general.Series cannot be resolved - jfreechart

Question

I have been updating my development environment to Eclipse Neon and introducing m2e to manage project dependencies. in one project the original (very old) versions of JFreeChart were not available on maven so I have put in the latest versions of JFreeChart and JCommon.
I now have one compile error, described below:
The type org.jfree.data.general.Series cannot be resolved.
It is indirectly referenced from required .class files.
I have found a number of questions and answers about this, but they seem to relate to the absence of JCommon. I have JCommon in my dependencies, and I have checked the specific class that is referred to is actually in the jfreechart.jar file with 7-zip.
Below is the code fragment with the error, which occurs on the last else statement results.add(…).
public XYDataset getMetricHistogramData(Timestamp t1, Timestamp t2){
int index1=-1;
Timestamp startTime,endTime;
TimePeriodValues results = new TimePeriodValues(this.type.name());
final TimePeriodValuesCollection results1 = new TimePeriodValuesCollection();
if (t1.before(earliest)||t1.after(latest)||(readings.size()<=1)) return null; // won't find a value for the timestamp t1
if (t2.before(earliest)||t2.after(latest)) return null; // won't find a value for the timestamp t2
for(int i = 0;i<readings.size();i++){
if (readings.get(i).timestamp().equals(t1)){
index1=i;
break;
}
if (readings.get(i).timestamp().after(t1)){
index1=i-1;
break;
}
}
// index1 now contains the index of the starting timestamp
for (int i=index1; i<(readings.size()-1); i++){
startTime = readings.get(i).timestamp();
if(startTime.after(t2)) break;
//endTime = new Timestamp(Math.abs(readings.get(i+1).timestamp().getTime()-Timestamped.SECOND_IN_MS));
endTime = readings.get(i+1).timestamp();
if (endTime.before(startTime))
SmartPower.getMain().getFrame().displayLog("Bad Timestamps "+startTime + " - " + endTime+"\n\r");
else results.add(new SimpleTimePeriod(startTime, endTime), readings.get(i).value());
}
results1.addSeries(results);
return results1;
}
This is my pom.xml file
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>SmartPower</groupId>
<artifactId>SmartPower</artifactId>
<version>0.0.1-SNAPSHOT</version>
<build>
<sourceDirectory>src</sourceDirectory>
<resources>
<resource>
<directory>src</directory>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
</resources>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.eclipse.persistence/javax.persistence -->
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>javax.persistence</artifactId>
<version>2.1.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jfree/jfreechart -->
<dependency>
<groupId>org.jfree</groupId>
<artifactId>jfreechart</artifactId>
<version>1.0.19</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jfree/jcommon -->
<dependency>
<groupId>org.jfree</groupId>
<artifactId>jcommon</artifactId>
<version>1.0.23</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.jgoodies/forms -->
<dependency>
<groupId>com.jgoodies</groupId>
<artifactId>forms</artifactId>
<version>1.2.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.derby/derby -->
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derby</artifactId>
<version>10.12.1.1</version>
</dependency>
</dependencies>
</project>
Neon was a clean install about a week ago on windows 10.
Any pointers would be appreciated.

Answer 1

I'm not sure where things are going awry. The class org.jfree.data.general.Series is indeed included in jfreechart-1.0.19.jar. You might try running from the command line with the -verbose option, as suggested here, to check for stray JARs. Using the 1.0.19 release,
$ java -verbose -cp .:lib/jfreechart-1.0.19.jar:lib/jcommon-1.0.23.jar Test
…
[Loaded org.jfree.data.general.SeriesDataset from file:lib/jfreechart-1.0.19.jar]
[Loaded org.jfree.data.xy.XYDataset from file:lib/jfreechart-1.0.19.jar]
…
Using the versions cited, the following simplified example produces the following chart without error:
import java.awt.Dimension;
import java.awt.EventQueue;
import javax.swing.JFrame;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.data.time.Day;
import org.jfree.data.time.TimePeriodValues;
import org.jfree.data.time.TimePeriodValuesCollection;
import org.jfree.data.xy.XYDataset;
/**
* #see https://stackoverflow.com/a/38725689/230513
*/
public class Test {
private void display() {
JFrame f = new JFrame("Test");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new ChartPanel(ChartFactory.createTimeSeriesChart(
"Title", "Domain", "Range", createDataset())) {
#Override
public Dimension getPreferredSize() {
return new Dimension(640, 480);
}
});
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private XYDataset createDataset() {
TimePeriodValues results = new TimePeriodValues("Data");
results.add(new Day(1, 8, 2016), 1);
results.add(new Day(2, 8, 2016), 2);
return new TimePeriodValuesCollection(results);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Test()::display);
}
}