Solution: If an error has occurred, you will have to display the error message by accessing the session scope attribute SPRING_SECURITY_LAST_EXCEPTION, which stores the last exception for the current user.

Solution: The logout service provides a handler to handle logout requests. It can be configured via the logout element.

Solution: By default, a user will be redirected to the context path root when the logout succeeds, but sometimes, you may wish to direct the user to another URL.

Solution: The anonymous login service can be configured via the anonymous element.

Solution: Remember-me support can be configured via the remember-me element.

Solution: Remember-me stores as cookie in the user’s browser not as cache.

Solution: Spring Security supports several algorithms for encoding passwords (including MD5 and SHA) and provides built-in password encoders for these algorithms.

Solution: To connect to a database in the Apache Derby server, you need the Derby client .jars, as well as the Spring JDBC support.

Solution: Spring Security also supports using custom SQL statements to query a legacy database for user details.

Solution: Jacksum, which you can download from http://sourceforge.net/projects/jacksum/ and extract to a directory of your choice. Then execute the following command to calculate a digest for a text:
java -jar jacksum.jar -a md5 -q “txt:secret”