Create UserBuilder

This commit creates a UserBuilder and updates samples to use it. We do not
leverate it for JdbcUserDetailsManager because it requires the schema to
be created which is difficult with a single bean definition and
unpredicatble ordering. For this, it is still advised to use
AuthenticationManagerBuilder

Fixes gh-4095

core/src/main/java/org/springframework/security/core/userdetails/User.java

@@ -17,9 +17,12 @@
 package org.springframework.security.core.userdetails;
 
 import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
+import java.util.List;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
@@ -27,6 +30,8 @@ import java.util.TreeSet;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.CredentialsContainer;
 import org.springframework.security.core.SpringSecurityCoreVersion;
+import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.util.Assert;
 
 /**
@@ -238,4 +243,183 @@ public class User implements UserDetails, CredentialsContainer {
 
 		return sb.toString();
 	}
+
+	public static UserBuilder withUsername(String username) {
+		return new UserBuilder().username(username);
+	}
+
+	/**
+	 * Builds the user to be added. At minimum the username, password, and authorities
+	 * should provided. The remaining attributes have reasonable defaults.
+	 */
+	public static class UserBuilder {
+		private String username;
+		private String password;
+		private List<GrantedAuthority> authorities;
+		private boolean accountExpired;
+		private boolean accountLocked;
+		private boolean credentialsExpired;
+		private boolean disabled;
+
+		/**
+		 * Creates a new instance
+		 */
+		private UserBuilder() {
+		}
+
+		/**
+		 * Populates the username. This attribute is required.
+		 *
+		 * @param username the username. Cannot be null.
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 */
+		private UserBuilder username(String username) {
+			Assert.notNull(username, "username cannot be null");
+			this.username = username;
+			return this;
+		}
+
+		/**
+		 * Populates the password. This attribute is required.
+		 *
+		 * @param password the password. Cannot be null.
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 */
+		public UserBuilder password(String password) {
+			Assert.notNull(password, "password cannot be null");
+			this.password = password;
+			return this;
+		}
+
+		/**
+		 * Populates the roles. This method is a shortcut for calling
+		 * {@link #authorities(String...)}, but automatically prefixes each entry with
+		 * "ROLE_". This means the following:
+		 *
+		 * <code>
+		 *     builder.roles("USER","ADMIN");
+		 * </code>
+		 *
+		 * is equivalent to
+		 *
+		 * <code>
+		 *     builder.authorities("ROLE_USER","ROLE_ADMIN");
+		 * </code>
+		 *
+		 * <p>
+		 * This attribute is required, but can also be populated with
+		 * {@link #authorities(String...)}.
+		 * </p>
+		 *
+		 * @param roles the roles for this user (i.e. USER, ADMIN, etc). Cannot be null,
+		 * contain null values or start with "ROLE_"
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 */
+		public UserBuilder roles(String... roles) {
+			List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>(
+					roles.length);
+			for (String role : roles) {
+				Assert.isTrue(!role.startsWith("ROLE_"), role
+						+ " cannot start with ROLE_ (it is automatically added)");
+				authorities.add(new SimpleGrantedAuthority("ROLE_" + role));
+			}
+			return authorities(authorities);
+		}
+
+		/**
+		 * Populates the authorities. This attribute is required.
+		 *
+		 * @param authorities the authorities for this user. Cannot be null, or contain
+		 * null values
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 * @see #roles(String...)
+		 */
+		public UserBuilder authorities(GrantedAuthority... authorities) {
+			return authorities(Arrays.asList(authorities));
+		}
+
+		/**
+		 * Populates the authorities. This attribute is required.
+		 *
+		 * @param authorities the authorities for this user. Cannot be null, or contain
+		 * null values
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 * @see #roles(String...)
+		 */
+		public UserBuilder authorities(List<? extends GrantedAuthority> authorities) {
+			this.authorities = new ArrayList<GrantedAuthority>(authorities);
+			return this;
+		}
+
+		/**
+		 * Populates the authorities. This attribute is required.
+		 *
+		 * @param authorities the authorities for this user (i.e. ROLE_USER, ROLE_ADMIN,
+		 * etc). Cannot be null, or contain null values
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 * @see #roles(String...)
+		 */
+		public UserBuilder authorities(String... authorities) {
+			return authorities(AuthorityUtils.createAuthorityList(authorities));
+		}
+
+		/**
+		 * Defines if the account is expired or not. Default is false.
+		 *
+		 * @param accountExpired true if the account is expired, false otherwise
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 */
+		public UserBuilder accountExpired(boolean accountExpired) {
+			this.accountExpired = accountExpired;
+			return this;
+		}
+
+		/**
+		 * Defines if the account is locked or not. Default is false.
+		 *
+		 * @param accountLocked true if the account is locked, false otherwise
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 */
+		public UserBuilder accountLocked(boolean accountLocked) {
+			this.accountLocked = accountLocked;
+			return this;
+		}
+
+		/**
+		 * Defines if the credentials are expired or not. Default is false.
+		 *
+		 * @param credentialsExpired true if the credentials are expired, false otherwise
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 */
+		public UserBuilder credentialsExpired(boolean credentialsExpired) {
+			this.credentialsExpired = credentialsExpired;
+			return this;
+		}
+
+		/**
+		 * Defines if the account is disabled or not. Default is false.
+		 *
+		 * @param disabled true if the account is disabled, false otherwise
+		 * @return the {@link UserBuilder} for method chaining (i.e. to populate
+		 * additional attributes for this user)
+		 */
+		public UserBuilder disabled(boolean disabled) {
+			this.disabled = disabled;
+			return this;
+		}
+
+		public UserDetails build() {
+			return new User(username, password, !disabled, !accountExpired,
+					!credentialsExpired, !accountLocked, authorities);
+		}
+	}
 }

core/src/main/java/org/springframework/security/provisioning/InMemoryUserDetailsManager.java

@@ -52,6 +52,9 @@ public class InMemoryUserDetailsManager implements UserDetailsManager {
 
 	private AuthenticationManager authenticationManager;
 
+	public InMemoryUserDetailsManager() {
+	}
+
 	public InMemoryUserDetailsManager(Collection<UserDetails> users) {
 		for (UserDetails user : users) {
 			createUser(user);