我尝试使用JSP和Servlet创建登录页面。它给了我一个并没有真正说出这么多的错误，所以我不知道从哪里开始才能解决它。
这是我的JSP代码：
<form class="form-horizontal" action="Login" method="POST">
<div class="form-group">
<label class="control-label col-sm-2" for="username">Username:</label>
<div class="col-sm-4">
<input type="text" class="form-control" id="username" placeholder="Enter username" name="un">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-2" for="pwd">Password:</label>
<div class="col-sm-4">
<input type="password" class="form-control" id="pwd" placeholder="Enter password" name="pwd">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-4">
<div class="checkbox">
<label><input type="checkbox" name="remember"> Remember me</label>
</div>
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-4">
<button type="submit" class="btn btn-success">Submit</button>
</div>
</div>
</form>
登录Servlet：
@WebServlet("/Login")
public class LoginServlet extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
try
{
User user = new User();
user.setUsername(request.getParameter("un"));
user.setPassword(request.getParameter("pwd"));
if (UserDAO.authUser(user))
{
System.out.println("in!");
HttpSession session = request.getSession(true);
session.setAttribute("currentSessionUser",user);
response.sendRedirect("home.jsp"); //logged-in page
}
else {
System.out.println("not in!");
response.sendRedirect("invalidLogin.jsp"); //error page
}
}
catch (Throwable theException)
{
System.out.println(theException);
}
}
}
我的pom依赖文件：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>licenta</groupId>
<artifactId>Tutoring</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>Tutoring Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.2.10.Final</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.5</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.10</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.5</version>
</dependency>
<dependency>
<groupId>dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>1.6.1</version>
</dependency>
<dependency>
<groupId>xalan</groupId>
<artifactId>xalan</artifactId>
<version>2.7.2</version>
</dependency>
<dependency>
<groupId>xerces</groupId>
<artifactId>xerces</artifactId>
<version>2.4.0</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.1</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-yaml</artifactId>
<version>2.8.6</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
<build>
<finalName>Tutoring</finalName>
</build>
</project>
错误日志如下所示：
Aug 11, 2017 6:44:41 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.j2ee.server:Tutoring' did not find a matching property.
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version: Apache Tomcat/7.0.78
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built: May 10 2017 15:02:19 UTC
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number: 7.0.78.0
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name: Windows 10
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version: 10.0
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture: amd64
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home: C:\Program Files\Java\jre1.8.0_121
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version: 1.8.0_121-b13
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor: Oracle Corporation
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE: C:\Users\buciu\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp2
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME: C:\Program Files\Apache Software Foundation\Tomcat 7.0
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=C:\Users\buciu\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp2
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=C:\Program Files\Apache Software Foundation\Tomcat 7.0
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dwtp.deploy=C:\Users\buciu\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp2\wtpwebapps
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.endorsed.dirs=C:\Program Files\Apache Software Foundation\Tomcat 7.0\endorsed
Aug 11, 2017 6:44:42 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dfile.encoding=Cp1252
Aug 11, 2017 6:44:42 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre1.8.0_121\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files/Java/jre1.8.0_121/bin/server;C:/Program Files/Java/jre1.8.0_121/bin;C:/Program Files/Java/jre1.8.0_121/lib/amd64;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Windows Live\Shared;C:\Program Files (x86)\Skype\Phone\;C:\Python27;C:\Anaconda;C:\Anaconda\Scripts;C:\Program Files\nodejs\;C:\Program Files\MySQL\MySQL Utilities 1.6\;C:\apache-maven-3.5.0\bin;C:\apache-maven-3.5.0;C:\Program Files\Java\jdk1.8.0_121\bin;C:\apache-maven-3.5.0\bin;C:\Users\buciu\Anaconda3;C:\Users\buciu\Anaconda3\Scripts;C:\Users\buciu\Anaconda3\Library\bin;C:\Users\buciu\AppData\Local\Programs\Python\Python36-32\Scripts\;C:\Users\buciu\AppData\Local\Programs\Python\Python36-32\;C:\RailsInstaller\Git\cmd;C:\RailsInstaller\Ruby2.3.0\bin;C:\Program Files\nodejs\;C:\Program Files(x86)\nodejs;C:\Users\buciu\AppData\Roaming\npm;C:\Users\me\AppData\Roaming\npm\node_modules\bower\bin;C:\apache-maven-3.5.0\bin;C:\apache-maven-3.5.0;C:\Users\buciu\Desktop;;.
Aug 11, 2017 6:44:44 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
Aug 11, 2017 6:44:44 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-bio-8009"]
Aug 11, 2017 6:44:44 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 5454 ms
Aug 11, 2017 6:44:44 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Aug 11, 2017 6:44:44 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.78
Aug 11, 2017 6:44:48 PM org.apache.catalina.util.SessionIdGeneratorBase createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [1,130] milliseconds.
Aug 11, 2017 6:44:50 PM org.apache.catalina.loader.WebappClassLoaderBase validateJarFile
INFO: validateJarFile(C:\Users\buciu\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp2\wtpwebapps\Tutoring\WEB-INF\lib\javax.servlet-api-3.1.0.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
Aug 11, 2017 6:44:58 PM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Aug 11, 2017 6:44:58 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
Aug 11, 2017 6:44:58 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
Aug 11, 2017 6:44:58 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 13927 ms
java.lang.NullPointerException
以下是UserDAO类：
public class UserDAO {
private static final Log LOGGER = LogFactory.getLog(UserDAO.class);
private static SessionFactory factory;
public UserDAO(SessionFactory factory) {
this.factory = factory;
}
public static User getUserByUsername(String username) {
Session session = factory.openSession();
Transaction tx = null;
List<User> result=null;
try{
tx = session.beginTransaction();
Query query = session.createQuery("FROM User WHERE username = :username ");
query.setParameter("username", username);
List<User> list = (List<User>)query.list();
result = list;
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
return result != null && !result.isEmpty() ? result.get(0) : null;
}
public void listUsers( ){
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
List users = session.createQuery("FROM User").list();
for (Iterator iterator =
users.iterator(); iterator.hasNext();){
User user = (User) iterator.next();
System.out.print("First Name: " + user.getUsername());
System.out.print("Last Name: " + user.getPassword());
System.out.println("Address: " + user.getAddress());
}
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
}
public static User addUser(User user) {
int userId = -1;
Session session = factory.openSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
userId = (Integer) session.save(user);
user.setId(userId);
tx.commit();
} catch (HibernateException e) {
if (tx != null) {
tx.rollback();
}
LOGGER.error("", e);
} finally {
session.close();
}
return user;
}
@SuppressWarnings("unchecked")
public User findUser(int id) {
Session session = factory.openSession();
Transaction tx = null;
List<User> users = null;
try {
tx = session.beginTransaction();
Query query = session.createQuery("FROM User WHERE id = :id");
query.setParameter("id", id);
users = query.list();
tx.commit();
} catch (HibernateException e) {
if (tx != null) {
tx.rollback();
}
LOGGER.error("", e);
} finally {
session.close();
}
return users != null && !users.isEmpty() ? users.get(0) : null;
}
public static boolean authUser(User user) {
// TODO Auto-generated method stub
User userDB = UserDAO.getUserByUsername(user.getUsername());
System.out.println(userDB.getUsername()+" "+userDB.getPassword());
System.out.println(user.getUsername()+" "+user.getPassword());
if (userDB != null && userDB.getUsername().equals(user.getUsername()) && userDB.getPassword().equals(user.getPassword())) {
return true;
} else {
return false;
}
}
// public User deleteUser(int id) {
// Session session = factory.openSession();
// Transaction tx = null;
// User user = (User)session.load(User.class, id);
// try {
// tx = session.beginTransaction();
// session.delete(user);
// tx.commit();
// } catch (HibernateException e) {
// if (tx != null) {
// tx.rollback();
// }
// LOGGER.error("", e);
// } finally {
// session.close();
// }
// return user;
// }
public void deleteUser(int id){
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
User user =
(User)session.get(User.class, id);
user.setDeleted(1);
session.update(user);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
}
}
它指示我一个LoginServlet的空白页面，没有打印任何内容，也没有将我重定向到其他东西。
这里有什么想法吗？非常感谢你提前了！