Java 如何修复“HTTP 状态 500- Servlet 异常引发异常”
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how to fix "HTTP Status 500- Servlet exception threw an exception"
提问by mellodi
i got this erore and i don't know what's wrong i just want to check the username & password and then enter a page that shows it login or not
我得到了这个错误，我不知道出了什么问题，我只想检查用户名和密码，然后输入一个显示它是否登录的页面
package cse;
import java.io.IOException;
import java.security.NoSuchAlgorithmException;
import java.util.Date;
import java.util.Random;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@SuppressWarnings("serial")
@WebServlet(urlPatterns = {"/LogIn"})
public class LogIn extends HttpServlet {
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
User signedInUser = User.login(username, password);
if(!signedInUser.equals(null)){
HttpSession s = request.getSession();
s.setAttribute("signedInKey", (new Date()).getTime() + (new Random()).nextInt(999999999));
request.setAttribute("user", signedInUser);
String url = "http://localhost:8080/java_project/test.jsp";
response.sendRedirect(url);
}
String url = "http://localhost:8080/java_project/notLogIn.jsp";
response.sendRedirect(url);
}
}
}
and this is the error
这是错误
HTTP Status 500 - Servlet execution threw an exception
--------------------------------------------------------------------------------
type Exception report
message Servlet execution threw an exception
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Servlet execution threw an exception
root cause
java.lang.NoClassDefFoundError: org/hibernate/Session
ir.ac.shirazu.cse.LogIn.doPost(LogIn.java:25)
javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
root cause
java.lang.ClassNotFoundException: org.hibernate.Session
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
ir.ac.shirazu.cse.LogIn.doPost(LogIn.java:25)
javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.40 logs.
--------------------------------------------------------------------------------
Apache Tomcat/7.0.40
plz help , i really can't understand what's wrong
请帮忙，我真的不明白出了什么问题
采纳答案by MorbidDesign
You need to put hibernate3.jar in classpath, specifically in the WEB-INF/libof your deployed application.
您需要将 hibernate3.jar 放在类路径中，特别是在WEB-INF/lib您部署的应用程序中。
In Eclipse IDE, you can do this right-clicking on your project -> Properties -> Deployment Assembly.
在 Eclipse IDE 中，您可以右键单击您的项目 -> 属性 -> 部署程序集。
Click Add... button, select Java Build Path Entries and click Next. Then select the desired jars to be exported to WEB-INF/liband click Finish. Automatically, the source jars will be deployed in the correct path.
单击 Add... 按钮，选择 Java Build Path Entries 并单击 Next。然后选择要导出到的所需 jarWEB-INF/lib并单击完成。源 jar 将自动部署在正确的路径中。
I hope this helps. It did for me.
我希望这有帮助。它对我有用。
回答by Aditya
remove the jar files and add them again in WEB-INF/lib
删除 jar 文件并在 WEB-INF/lib 中再次添加它们
