How to solve this java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream?

问题

I am using the below code to upload a file in to tomcat5.5 and it gives me the following exception

java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream

could you please help me to find it out?

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

/**
 * Servlet implementation class FileUploadServlet
 */
public class FileUploadServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public FileUploadServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    @SuppressWarnings(\"rawtypes\")
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        boolean isMultipart = ServletFileUpload.isMultipartContent(request);
        System.out.println(\"Status : \"+isMultipart);
        if (isMultipart) {
            FileItemFactory factory = new DiskFileItemFactory();
            ServletFileUpload upload = new ServletFileUpload(factory);

            try {
                List items = upload.parseRequest(request);
                Iterator iterator = items.iterator();
                while (iterator.hasNext()) {
                    FileItem item = (FileItem) iterator.next();

                    if (!item.isFormField()) {
                        String fileName = item.getName();

                        String root = getServletContext().getRealPath(\"/\");
                        File path = new File(root + \"/uploads\");
                        if (!path.exists()) {
                            boolean status = path.mkdirs();
                        }

                        File uploadedFile = new File(path + \"/\" + fileName);
                        System.out.println(uploadedFile.getAbsolutePath());
                        item.write(uploadedFile);
                    }
                }
            } catch (FileUploadException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        response.sendRedirect(\"upload.jsp\");
    }

}

this is the jar i use commons-fileupload-1.2.2.jar

回答1:

The particular exception message is telling you that the mentioned class is missing in the classpath. As the org.apache.commons.io package name hints, the mentioned class is part of the http://commons.apache.org/io project.

And indeed, Commons FileUpload has Commons IO as a dependency. You need to download and drop commons-io.jar in the /WEB-INF/lib as well.

回答2:

use maven dependency

<dependency> 
  <groupId>org.apache.commons</groupId>
  <artifactId>commons-io</artifactId> 
  <version>1.3.2</version> 
</dependency>

or download commons-io.1.3.2.jar to your lib folder

回答3:

Solution

By default, Struts is using Apache “commons-io.jar” for its file upload process. To fix it, you have to include this library into your project dependency library folder.

Get Directly

Get “commons-io.jar” from official website – http://commons.apache.org/io/

Get From Maven

The prefer way is get the “commons-io.jar” from Maven repository

File : pom.xml

  <dependency>
    <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
    <version>1.4</version>
  </dependency>

回答4:

just put all apache comons jar and file upload jar in lib folder of tomcat

回答5:

If you are receiving this error in a WebSphere container, then make sure you set your Apps class loading policy correctly. I had to change mine from the default to 'parent last' and also ‘Single class loader for application’ for the WAR policy. This is because in my case the commons-io*.jar was packaged with in the application, so it had to be loaded first.

回答6:

Download PrimeFaces 4.0. It solved my issue right away. I'm using Glassfish 4.0

来源：https://stackoverflow.com/questions/11154252/how-to-solve-this-java-lang-noclassdeffounderror-org-apache-commons-io-output-d

标签

servlets

upload

tomcat5.5