java.lang.NoClassDefFoundError : org/apache/commons/lang3/ObjectUtils [duplicate] - servlets

Question

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java.lang.NoClassDefFoundError: org/apache/commons/lang3/ObjectUtils
(1 answer)
Closed 5 years ago.
I'm trying to write a very simple servlet which must extract data from a csv file and display the result, here is the code:
Reader reader = new FileReader(filePath);
CSVReader csvReader = new CSVReader(reader);
String[] data;
PrintWriter out = response.getWriter();
response.setContentType("text/html");
while((data = csvReader.readNext()) != null){
//do something
}
but then I receive this log:
Type Exception Report
Message Servlet execution threw an exception
Description The server encountered an unexpected condition that
prevented it from fulfilling the request.
Exception
javax.servlet.ServletException: Servlet execution threw an exception
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
java.lang.NoClassDefFoundError: org/apache/commons/lang3/ObjectUtils
com.opencsv.CSVParser.(CSVParser.java:209)
com.opencsv.CSVReader.(CSVReader.java:196)
com.opencsv.CSVReader.(CSVReader.java:178)
com.opencsv.CSVReader.(CSVReader.java:130)
com.opencsv.CSVReader.(CSVReader.java:70)
TheClass.doGet(TheClass.java:19)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Note
The full stack trace of the root cause is available in the server
logs.
I'set the tomcat-websocket CLASSPATH and copied the jar file in lib directory in WEB-INF but non of them affected.
The problem is raised when we make a CSVReader class. Is there anyone for some helps?

Answer 1

You are saying you have the jar file for opencsv but do you have the jar files for the dependencies? Opencsv has dependencies on two to three apache commons libraries depending on which version of opencsv you are using. The dependencies of the latest version can be found at http://opencsv.sourceforge.net/dependencies.html.
If you are building your project using maven or gradle you should have these dependencies already included in your war file. How are you building/deploying your app?