Refactor MyUserDetailsService

spring-security-mvc-persisted-remember-me/src/main/java/org/baeldung/service/MyUserDetailsService.java

@@ -1,11 +1,5 @@
 package org.baeldung.service;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.baeldung.security.SecurityRole;
@@ -17,9 +11,9 @@ import org.springframework.security.core.userdetails.UserDetailsService;
 import org.springframework.security.core.userdetails.UsernameNotFoundException;
 import org.springframework.stereotype.Service;
 
-/**
- * User Details Service - hard coded to two users for the example.
- */
+import java.util.*;
+import java.util.stream.Collectors;
+
 @Service
 public class MyUserDetailsService implements UserDetailsService {
 
@@ -28,24 +22,19 @@ public class MyUserDetailsService implements UserDetailsService {
     private final Map<String, User> availableUsers = new HashMap<String, User>();
 
     public MyUserDetailsService() {
-
         populateDemoUsers();
-
     }
 
-    //
-
     @Override
     public UserDetails loadUserByUsername(final String username) throws UsernameNotFoundException {
         logger.info("Load user by username " + username);
 
         final UserDetails user = availableUsers.get(username);
         if (user == null) {
-            throw new UsernameNotFoundException("Username not found");
-        } else {
-            return availableUsers.get(username);
+            throw new UsernameNotFoundException(username);
         }
 
+        return user;
     }
 
     /**
@@ -59,24 +48,13 @@ public class MyUserDetailsService implements UserDetailsService {
         availableUsers.put("admin", createUser("admin", "password", Arrays.asList(SecurityRole.ROLE_ADMIN)));
     }
 
-    /**
-     * Create a demo User.
-     * 
-     * @param username
-     *            Username
-     * @param password
-     *            Password
-     * @param roles
-     *            Role names user is assigned to
-     * @return User
-     */
     private User createUser(final String username, final String password, final List<SecurityRole> roles) {
         logger.info("Create user " + username);
 
-        final List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();
-        for (final SecurityRole role : roles) {
-            authorities.add(new SimpleGrantedAuthority(role.toString()));
-        }
+        final List<GrantedAuthority> authorities = roles.stream()
+          .map(role -> new SimpleGrantedAuthority(role.toString()))
+          .collect(Collectors.toList());
+
         return new User(username, password, true, true, true, true, authorities);
     }
 }