为什么在使用OpenCSV时会出现’ClassNotFound’异常？

huangapple
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英文:

why do i get 'ClassNotFound' exception when using OpenCSV

问题

这是我翻译好的内容：

  1. 我正在尝试使用opencsv读取CSV文件，我已经导入了所有内容并将库引用到了类路径中，但是我一直在收到ClassNotFoundException错误：
  3. 以下是我的代码：
  5.     import java.io.File;
  6.     import java.io.FileNotFoundException;
  7.     import java.io.FileReader;
  8.     import java.io.IOException;
  9.     import java.util.ArrayList;
  10.     import com.opencsv.CSVReader;
  12.     public class Main {
  14.     public static void main(String[] args) {
  15.         // TODO Auto-generated method stub
  16.     
  17.         CSVReader readActors;
  18.         try {
  19.             readActors = new CSVReader(new FileReader(new File("src\\prueba\\actors.csv")));
  20.                 
  21.         String[] values = null;
  22.       
  23.             try {
  24.                 while ((values = readActors.readNext()) != null){
  25.                     String name =values[0];
  26.                     String bday = values[1];
  27.                     
  28.                     System.out.println("Name:" +name+", bday:" +bday); //check if reading is ok
  29.                 }
  30.             } catch (IOException e) {
  31.                 // TODO Auto-generated catch block
  32.                 e.printStackTrace();
  33.             }    
  34.             
  35.         } catch (FileNotFoundException e) {
  36.             // TODO Auto-generated catch block
  37.             e.printStackTrace();
  38.         }
  39.     }
  40.         
  41.     }
  43. 以下是我收到的异常：
  45.     Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/lang3/ObjectUtils
  46.     at com.opencsv.CSVParser.<init>(CSVParser.java:207)
  47.     at com.opencsv.CSVReader.<init>(CSVReader.java:198)
  48.     at com.opencsv.CSVReader.<init>(CSVReader.java:180)
  49.     at com.opencsv.CSVReader.<init>(CSVReader.java:132)
  50.     at com.opencsv.CSVReader.<init>(CSVReader.java:72)
  51.     at prueba.Main.main(Main.java:20)
  52.     Caused by: java.lang.ClassNotFoundException: org.apache.commons.lang3.ObjectUtils
  53.     at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
  54.     at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
  55.     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
  56.     ... 6 more
  58. CSV文件的内容如下，同样位于'prueba'包中，以及Main类。
  60.     Margot Robbie,02/07/1990
  61.     Leonardo DiCaprio,11/11/1974
  62.     Brad Pitt,18/12/1963
英文:

I'm trying to read a CSV file using opencsv, I have imported everything and referenced the library in the classpath but i keep getting the ClassNotFoundException:

Here's my code:

  1. import java.io.File;
  2. import java.io.FileNotFoundException;
  3. import java.io.FileReader;
  4. import java.io.IOException;
  5. import java.util.ArrayList;
  6. import com.opencsv.CSVReader;
  7. public class Main {
  8. public static void main(String[] args) {
  9. // TODO Auto-generated method stub
  10. CSVReader readActors;
  11. try {
  12. readActors = new CSVReader(new FileReader(new File(&quot;src\\prueba\\actors.csv&quot;)));
  13. String[] values = null;
  14. try {
  15. while ((values = readActors.readNext()) != null){
  16. String name =values[0];
  17. String bday = values[1];
  18. System.out.println(&quot;Name:&quot; +name+&quot;, bday:&quot; +bday); //check if reading is ok
  19. }
  20. } catch (IOException e) {
  21. // TODO Auto-generated catch block
  22. e.printStackTrace();
  23. }	
  24. } catch (FileNotFoundException e) {
  25. // TODO Auto-generated catch block
  26. e.printStackTrace();
  27. }
  28. }
  29. }

Here are the exceptions I'm getting:

  1. Exception in thread &quot;main&quot; java.lang.NoClassDefFoundError: org/apache/commons/lang3/ObjectUtils
  2. at com.opencsv.CSVParser.&lt;init&gt;(CSVParser.java:207)
  3. at com.opencsv.CSVReader.&lt;init&gt;(CSVReader.java:198)
  4. at com.opencsv.CSVReader.&lt;init&gt;(CSVReader.java:180)
  5. at com.opencsv.CSVReader.&lt;init&gt;(CSVReader.java:132)
  6. at com.opencsv.CSVReader.&lt;init&gt;(CSVReader.java:72)
  7. at prueba.Main.main(Main.java:20)
  8. Caused by: java.lang.ClassNotFoundException: org.apache.commons.lang3.ObjectUtils
  9. at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
  10. at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
  11. at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
  12. ... 6 more

and the csv file looks like this and is located in the package 'prueba' as well as the Main class.

  1. Margot Robbie,02/07/1990
  2. Leonardo DiCaprio,11/11/1974
  3. Brad Pitt,18/12/1963

答案1

得分: 2

看起来您还需要将 org.apache.commons.lang3 的 JAR 包添加到类路径中。也许可以尝试访问这个网站：https://commons.apache.org/proper/commons-lang/download_lang.cgi

英文:

Looks like you also need to add org.apache.commons.lang3 jar to the classpath. Maybe try this site https://commons.apache.org/proper/commons-lang/download_lang.cgi

huangapple
  • 本文由 发表于 2020年4月7日 05:46:09
  • 转载请务必保留本文链接：https://go.coder-hub.com/61069458.html
  • csv
  • java
  • opencsv
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