如何导入commons-io.jar jsp / java

Question

I am getting an exception:

Cannot find symbol: FileUploadException; 

I have a piece of code which uses

FileUploadException

The library that needs importing is:

org.apache.commons.fileupload.FileUploadException

The path to my project is :

D:\Projects\website

In the project folder I have each in its folder:

Tomcat, Derby, Website

I have copied:

commons-fileupload.jar and commons-io.jar

into both:

Tomcat/lib and Website/Web-INF/lib

---------------I tried this--------------

just importing the library on its own

import org.apache.commons.fileupload.FileUploadException;

adding the jars to the class path upon build:

javac -cp .;D:Projects\website\Tomcat\lib\commons-fileupload.jar;D:\Projects\website\Tomcat\lib\commons-io.jar com/otrocol/app/*.java

adding them to the Environment variables CLASSPATH

D:Projects\website\Tomcat\lib\commons-fileupload.jar;D:\Projects\website\Tomcat\lib\commons-io.jar

I also tried adding the jars where my .java files are as @Scot Ship suggested

----mentions---

I am not using any IDE

The code contains more unrecognized symbols, but I'm trying to solve one at a time

First time using apache, tomcat, jsp.. please be gentle

Answer 1

Vlad, the web container will automatically look for JARs inside

/WEB-INF/lib

even without any developer intervention. Take note that it's all caps WEB-INF. As long as your JAR is there, it will be in your web application's classpath.

Try to display this in one of your servlets or JSP:

System.getProperty("java.class.path")

and you'll get a better view of what classes and JARs were actually loaded.

Update: After reviewing your question, it appears you're facing issues in compiling the files to begin with and you're doing it outside an IDE.

Take note that when you use -cp in javac like this:

javac -cp .;D:Projects\website\Tomcat\lib\commons-fileupload.jar;D:\Projects\website\Tomcat\lib\commons-io.jar com/otrocol/app/*.java

Whatever value you have set in the CLASSPATH environment variable becomes ignored.

Be absolutely sure that the class FileUploadException is indeed inside one of the JARs you're trying to import: you can view the JAR directly using an unarchiving tool.

Also, change the com/otrocol/app/*.java to com\\otrocol\\app*.java - you should be using your system delimiter (not that this may affect your problem).

Create a simple HelloWorld in the same location as the file you're compiling, add the SystemOut mentioned above, and compile it the same way you're doing for the concerned file.

Answer 2

Read this http://commons.apache.org/proper/commons-fileupload/faq.html#class-not-found . Probably you have the fileupload jar but you also need commons-io.jar in your classpath as well.