I am trying to create login and registration form using spring. I'm new to spring.

I am getting this error:

Cannot invoke "org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder.encode(java.lang.CharSequence)" because "net.cdac.TMS.service.UserServiceImpl.passwordEncoder" is null java.lang.NullPointerException: Cannot invoke "org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder.encode(java.lang.CharSequence)" because "net.cdac.TMS.service.UserServiceImpl.passwordEncoder" is null at net.cdac.TMS.service.UserServiceImpl.save(UserServiceImpl.java:36) at net.cdac.TMS.web.UserRegistrationController.registerUserAccount(UserRegistrationController.java:36) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1070) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) at javax.servlet.http.HttpServlet.service(HttpServlet.java:681) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:327) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:122) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:116) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:126) at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:81) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:109) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:223) at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:217) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103) at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:132) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90) at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:112) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:82) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:55) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.session.DisableEncodeUrlFilter.doFilterInternal(DisableEncodeUrlFilter.java:42) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:211) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:183) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:354) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:267) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.base/java.lang.Thread.run(Thread.java:833)

My code for User.java is

package net.cdac.TMS.model;

import java.util.Collection;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
import javax.persistence.JoinColumn;

@Entity
@Table(name = "user", uniqueConstraints = @UniqueConstraint(columnNames = "uemailid"))
public class User {

    @GeneratedValue(strategy =  GenerationType.IDENTITY)
    private Long id;
    @Column(name = "uname")
    private String uName;


    @Id
    @Column(name = "uemailid")
    private String uemailid;

    private String upassword;

    private String usecurityQ;

    private String usecurityA;

    @ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinTable(
            name = "users_roles",
            joinColumns = @JoinColumn(
                    name = "user_id", referencedColumnName = "id"),
            inverseJoinColumns = @JoinColumn(
                            name = "role_id", referencedColumnName = "id"))
    
    private Collection<Role> roles;
    public User() {

    }
    public User(String email, String password) {

    }

    public User(String Name, String email, String password, String securityQ, String securityA, Collection<Role> roles) {
        super();
        this.uName = Name;
        this.uemailid = email;
        this.upassword = password;
        this.usecurityA = securityQ;
        this.usecurityA = securityA;
        this.roles = roles;
    }

    public String getUemailid() {
        return uemailid;
    }

    public void setUemailid(String uemailid) {
        this.uemailid = uemailid;
    }
    
    public String getuName() {
        return uName;
    }

    public void setuName(String uName) {
        this.uName = uName;
    }

    public String getUpassword() {
        return upassword;
    }

    public void setUpassword(String upassword) {
        this.upassword = upassword;
    }

    public String getUsecurityQ() {
        return usecurityQ;
    }

    public void setUsecurityQ(String usecurityQ) {
        this.usecurityQ = usecurityQ;
    }

    public String getUsecurityA() {
        return usecurityA;
    }

    public void setUsecurityA(String usecurityA) {
        this.usecurityA = usecurityA;
    }
    public Collection<Role> getRoles() {
        return roles;
    }
    public void setRoles(Collection<Role> roles) {
        this.roles = roles;
    }

}

The UserServiceImpl.java code is

package net.cdac.TMS.service;

import java.util.Arrays;
import java.util.Collection;
import java.util.stream.Collectors;
import net.cdac.TMS.model.Role;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.stereotype.Service;

import net.cdac.TMS.model.User;
import net.cdac.TMS.repository.UserRepository;
import net.cdac.TMS.web.dto.UserRegistrationDto;

@Service
public class UserServiceImpl implements UserService{

    private UserRepository userRepository;
    
    @Autowired
    private static BCryptPasswordEncoder passwordEncoder;

    public UserServiceImpl(UserRepository userRepository) {
        super();
        this.userRepository = userRepository;
    }

    @Override
    public User save(UserRegistrationDto registrationDto) {
        User user = new User(registrationDto.getuName(),registrationDto.getUemail(),
                passwordEncoder.encode(registrationDto.getUpassword()),registrationDto.getUsecurityQ(),registrationDto.getUsecurityA(),Arrays.asList(new Role("ROLE_USER")) );
        
        return userRepository.save(user);
    }

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
    
        User user = userRepository.findByUemailid(username);
        if(user == null) {
            throw new UsernameNotFoundException("Invalid username or password.");
        }
        return new org.springframework.security.core.userdetails.User(user.getUemailid(), user.getUpassword(), mapRolesToAuthorities(user.getRoles()));
            
    }
        private Collection<? extends GrantedAuthority> mapRolesToAuthorities(Collection<Role> roles){
        return roles.stream().map(role -> new SimpleGrantedAuthority(role.getName())).collect(Collectors.toList());
    }
    
}

The UserRegistrationDto.java:

package net.cdac.TMS.web.dto;

public class UserRegistrationDto {
    private String uName;
    private String uemail;
    private String upassword;
        private String usecurityQ;
        private String usecurityA;

    public UserRegistrationDto(){
        
    }
    
    public UserRegistrationDto(String firstName,String email, String password,String securityQ, String securityA) {
        super();
        this.uName = firstName;
        this.usecurityQ = securityQ;
        this.uemail = email;
        this.upassword = password;
                this.usecurityA = securityA;
    }
    
    public String getuName() {
        return uName;
    }
    public void setuName(String firstName) {
        this.uName = firstName;
    }
    
    public String getUemail() {
        return uemail;
    }
    public void setUemail(String email) {
        this.uemail = email;
    }
    public String getUpassword() {
        return upassword;
    }
    public void setUpassword(String password) {
        this.upassword = password;
    }
        public String getUsecurityQ() {
        return usecurityQ;
    }
    public void setUsecurityQ(String securityQ) {
        this.usecurityQ = securityQ;
    }
        public String getUsecurityA() {
        return usecurityA;
    }
    public void setUsecurityA(String securityA) {
        this.usecurityA = securityA;
    }
}

The UserRegistrationController.java:

package net.cdac.TMS.web;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import net.cdac.TMS.service.UserService;
import net.cdac.TMS.web.dto.UserRegistrationDto;

@Controller
@RequestMapping("/registration")
public class UserRegistrationController {

    private UserService userService;

    public UserRegistrationController(UserService userService) {
        super();
        this.userService = userService;
    }
    
    @ModelAttribute("user")
    public UserRegistrationDto userRegistrationDto() {
        return new UserRegistrationDto();
    }
    
    @GetMapping
    public String showRegistrationForm() {
        return "registration";
    }
    
    @PostMapping
    public String registerUserAccount(@ModelAttribute("user") UserRegistrationDto registrationDto) {
        userService.save(registrationDto);
        return "redirect:/registration?success";
    }
}

The Role.java code:

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package net.cdac.TMS.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "role")
public class Role {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    
    public Role() {
        
    }
    
    public Role(String name) {
        super();
        this.name = name;
    }
    
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

I don't understand what is causing the error and how to resolve it. Thank you in advance for helping.

CodePudding user response：

@Autowired private static BCryptPasswordEncoder passwordEncoder;

modify @Autowired private BCryptPasswordEncoder passwordEncoder;