无法解析类型org.jfree.data.general.Series

Question

我一直在将我的开发环境更新到Eclipse Neon并引入了m2e来管理项目依赖关系。在一个项目中，原始（非常旧）版本的JFreeChart在maven上不可用，所以我已经放入最新版本的JFreeChart和JCommon。

我现在有一个编译错误，说明如下：

The type org.jfree.data.general.Series cannot be resolved. 
It is indirectly referenced from required .class files. 

我已经找到了一些关于这个问题和答案，但他们似乎都与缺乏JCommon。我在我的依赖关系中有JCommon，并且我已经检查过提到的具体类实际上是带有7-zip的jfreechart.jar文件。 下面是带有错误的代码片段，它出现在last else语句results.add(…)上。

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; 
} 

这是我的pom.xml文件

<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> 

霓虹灯是一个干净的前窗上10

任何指针将不胜感激安装一个星期左右。

Answer 1

我不确定事情会发生错误。 org.jfree.data.general.Series确实包含在jfreechart-1.0.19.jar中。您可以尝试使用-verbose选项从命令行运行，如建议here，以检查是否有流浪JAR。使用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] 
… 

使用的版本引用，以下简化示例产生下面的图表没有错误：

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); 
    } 
}