servlet上传java图像导致类未找到异常

Question

例外情况

    Aug 06, 2015 5:09:58 PM org.apache.catalina.core.ApplicationContext log
INFO: Marking servlet FileUploadHandler as unavailable
Aug 06, 2015 5:09:58 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Allocate exception for servlet FileUploadHandler
java.lang.ClassNotFoundException: FileUploadHandler
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1678)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1523)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:415)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:397)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1099)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:836)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:185)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:151)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:269)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:300)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:722)

网络。xml

    <?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

   <servlet>
        <servlet-name>FileUploadHandler</servlet-name>
        <servlet-class>FileUploadHandler</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>FileUploadHandler</servlet-name>
        <url-pattern>/upload</url-pattern>
    </servlet-mapping>

</web-app>

FileUploadHandler。java

 package mypackage;
import java.io.File;
import java.io.IOException;
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.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;


public class FileUploadHandler extends HttpServlet {
    private final String UPLOAD_DIRECTORY = "/uploads";

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        //process only if its multipart content
        if(ServletFileUpload.isMultipartContent(request)){
            try {
                List<FileItem> multiparts = new ServletFileUpload(
                                         new DiskFileItemFactory()).parseRequest(request);

                for(FileItem item : multiparts){
                    if(!item.isFormField()){
                        String name = new File(item.getName()).getName();
                        item.write( new File(UPLOAD_DIRECTORY + File.separator + name));
                    }
                }

               //File uploaded successfully
               request.setAttribute("message", "File Uploaded Successfully");
            } catch (Exception ex) {
               request.setAttribute("message", "File Upload Failed due to " + ex);
            }          

        }else{
            request.setAttribute("message",
                                 "Sorry this Servlet only handles file upload request");
        }

        //request.getRequestDispatcher("/result.jsp").forward(request, response);

    }

}

输入。jsp

 <form id="upload" method="post" action="upload" enctype="multipart/form-data">
                                <input name="upl" multiple="" type="file">
                           <input type="submit" value="upload">

                        </form>

当我上传一个文件到一个目录时，我得到了一个servlet异常。 我想使用servlet或任何其他适合上传和检索该图像的方法将图像上传到目录

Answer 1

您的web.xml配置不正确；<servlet-class>必须包含完整的类名，包括包，如下所示：

<servlet-class>mypackage.FileUploadHandler</servlet-class>

Answer 2

servlet-class必须是servlet类的完全限定名：

mypackage.FileUploadHandler