我创建了一个 jsp 文件 register.jsp，在其中获取用户的详细信息并尝试将其保存在数据库中 RegisterServlet.java
package com.controller;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.model.User;
import com.service.RegisterService;
public class RegisterServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String firstName = request.getParameter("firstName");
String middleName = request.getParameter("middleName");
String lastName = request.getParameter("lastName");
String email = request.getParameter("email");
String userId = request.getParameter("userId");
String password = request.getParameter("password");
User user = new User(firstName,middleName,lastName, email,userId, password);
try {
RegisterService registerService = new RegisterService();
boolean result = registerService.register(user);
out.println("<html>");
out.println("<head>");
out.println("<title>Registration Successful</title>");
out.println("</head>");
out.println("<body>");
out.println("<center>");
if(result){
out.println("<h1>Thanks for Registering with us :</h1>");
out.println("To login with new UserId and Password<a href=login.jsp>Click here</a>");
}else{
out.println("<h1>Registration Failed</h1>");
out.println("To try again<a href=register.jsp>Click here</a>");
}
out.println("</center>");
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" 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">
<display-name>MVCApplication</display-name>
<servlet>
<display-name>LoginServlet</display-name>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>com.controller.LoginServlet</servlet-class>
</servlet>
<servlet>
<display-name>RegisterServlet</display-name>
<servlet-name>RegisterServlet</servlet-name>
<servlet-class>com.controller.RegisterServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>InsertDataItem</servlet-name>
<servlet-class>com.controller.InsertDataItem</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>RegisterServlet</servlet-name>
<url-pattern>/RegisterServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>InsertDataItem</servlet-name>
<url-pattern>/InsertDataItem</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
</web-app>
错误
**exception**
javax.servlet.ServletException: Error instantiating servlet class com.controller.RegisterServlet
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:745)
**root cause**
java.lang.ClassNotFoundException: com.controller.RegisterServlet
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1285)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:745)
Whenever I submit my details to register in the database this error pops up!. Can anyone please help me ??
最佳答案
您需要确保 RegisterServlet 类实际上可用于 servlet 容器。
通常，在 WEB-INF 目录中，您将具有以下目录:
- 库
- 类(class)
您需要确保该类在classes目录中可用或者该类位于lib目录中的JAR中
关于java - HTTP 状态 500 - 实例化 servlet 类 com.controller.RegisterServlet 时出错，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42807998/