java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory [英] java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory
问题描述
我正在尝试通过 apache tomcat 8.0.14 编译 UploadServlet servlet.我的 web.xml 很好，UploadServlet.java 已正确编译，但是当我尝试运行时出现以下错误
I am trying to compile UploadServlet servlet via apache tomcat 8.0.14.
my web.xml is fine andUploadServlet.java has compiled properly but yet when try to run i get following error
错误
HTTP Status 500 - Error instantiating servlet class UploadServlet
exception
javax.servlet.ServletException: Error instantiating servlet class UploadServlet
root cause
java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory
root cause
java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory
UploadServlet.java
import java.io.*;
import java.util.*;
import javax.servlet.ServletConfig;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.output.*;
public class UploadServlet extends HttpServlet {
private boolean isMultipart;
private String filePath;
private int maxFileSize = 50 * 1024;
private int maxMemSize = 4 * 1024;
private File file ;
public void init( ){
filePath = getServletContext().getInitParameter("file-upload");
}
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, java.io.IOException {
isMultipart = ServletFileUpload.isMultipartContent(request);
response.setContentType("text/html");
java.io.PrintWriter out = response.getWriter( );
if( !isMultipart ){
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet upload</title>");
out.println("</head>");
out.println("<body>");
out.println("<p>No file uploaded</p>");
out.println("</body>");
out.println("</html>");
return;
}
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(maxMemSize);
factory.setRepository(new File("C:\apache-tomcat-8.0.14\temp"));
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setSizeMax( maxFileSize );
try{
List fileItems = upload.parseRequest(request);
Iterator i = fileItems.iterator();
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet upload</title>");
out.println("</head>");
out.println("<body>");
while ( i.hasNext () )
{
FileItem fi = (FileItem)i.next();
if ( !fi.isFormField () )
{
String fieldName = fi.getFieldName();
String fileName = fi.getName();
String contentType = fi.getContentType();
boolean isInMemory = fi.isInMemory();
long sizeInBytes = fi.getSize();
System.out.println(fileName);
if( fileName.lastIndexOf("\") >= 0 )
{
file = new File( filePath +
fileName.substring(fileName.lastIndexOf("\"))) ;
}
else
{
file = new File( filePath +
fileName.substring(fileName.lastIndexOf("\")+1)) ;
}
fi.write( file ) ;
out.println("Uploaded Filename: " + fileName + "<br>");
}
}
out.println("</body>");
out.println("</html>");
}catch(Exception ex) {
System.out.println(ex);
}
}
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, java.io.IOException {
throw new ServletException("GET method used with " +
getClass( ).getName( )+": POST method required.");
}
}
推荐答案
你需要把 commons-fileupload.jar 和 commons-io.jar 放到你的WEB-INF/lib 文件夹.类路径在构建期间使用，但它们也必须在运行时可用.
You need to put commons-fileupload.jar and commons-io.jar to your WEB-INF/lib forlder. Classpath is used during build, but they must be available during runtime also.
实际上，如果您使用 IDE 进行 Java EE 开发(如 Eclipse)，将这些 Jars 放在 WEB-INF/lib 中就足够了，因为它们会在构建的 claspath 中自动可见.
Actually, if you had used IDE for Java EE development (like Eclipse) putting these Jars to WEB-INF/lib would be enough, as they would be automatically visible in the claspath for build.
这篇关于java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
