Java EL expressions

nevisAuth supports the Java Expression Language (Java EL) 5.0 syntax at the same locations as variable expressions. Java EL uses the customary ${...} or #{...} syntax, without difference in evaluation.

EL and variable expressions

In some cases, nevisAuth interprets valid Java EL expressions as variable expressions, which causes an empty result. This happens if the EL expression starts with a known variable expression source, followed by a potentially valid property name. See also Variable expressions. For example: nevisAuth will not evaluate ${notes.containsKey('test')} as an EL expression because notes is a valid variable expression source and containsKey might be the name of a custom notes property.

To prevent such confusion, use one of the following variants:

#{notes.containsKey('test')}

${ notes.containsKey('test')} (the extra space after ${ is intentional)

A full discussion of Java EL is beyond the scope of this document. See the Jakarta EL Specification for an in-depth introduction. However, the details of the usage of Java EL may differ from the usage patterns in nevisAuth.

info

nevisAuth implements an extended EL engine that supports invocations of static methods and that its invocation resolver extends the specified EL invocation procedure by considering method parameter types. This allows the use of overloaded methods, varArg methods, static invocation and similar features of Java that are not supported in Java EL 5.0.

EL context beans

The following table shows beans and helper classes that can be used in an EL expression in nevisAuth. See the JavaDoc documentation of the classes for a complete list of accessible methods.

Bean	Class	Description
request	ch.nevis.esauth.auth.engine.AuthRequest	Request object of nevisAuth.Invocation of some methods is forbidden for security reasons.
response	ch.nevis.esauth.auth.engine.AuthResponse	Response object of nevisAuth.Invocation of some methods is forbidden for security reasons.
sess	java.util.Map	The user session.
inctx	java.util.Properties	Incoming context values, as provided by the client.
inargs	java.util.Properties	Input parameters provided by the user
outargs	java.util.Properties	Output value to send to the client.
notes	java.util.Properties	Short-term notes pertaining to the current request/response iteration.
litdict	java.util.ResourceBundle	Literal dictionary for the user's language. Cannot be used if useLiteralDictionary was set to false in the AuthEngine configuration.
property	java.util.Properties	Java system properties.
oocd	ch.nevis.esauth.ooc.OutOfContextDataService	The singleton instance of the OutOfContextDataService which allows to store data outside of the user's context.
Arrays	java.util.Arrays	Helper classes whose static methods may be invoked like regular bean methods.
Collections	java.util.Collections
Math	java.lang.Math
Locale	java.util.Locale
String	java.lang.String
Integer	java.lang.Integer
Long	java,lang.Long
BigInteger	java.math.BigInteger
Float	java.lang.Float
Boolean	java.lang.Boolean
StringUtils	org.apache.commons.lang.StringUtils	Helper classes from the Apache Commons library whose static methods may be invoked like regular bean methods.
StringEscapeUtils	org.apache.commons.lang.StringEscapeUtils
DateTimeFormatter	java.time.format.DateTimeFormatter
Instant	java.time.Instant
LocalDate	java.time.LocalDate
LocalDateTime	java.time.LocalDateTime
LocalDateTime	java.time.LocalDateTime
OffsetDateTime	java.time.OffsetDateTime
ZoneOffset	java.time.ZoneOffset
ZoneId	java.time.ZoneId
ChronoUnit	java.time.temporal.ChronoUnit
Duration	java.time.Duration
PhoneNumberUtil	com.google.i18n.phonenumbers.PhoneNumberUtil	Helper classes from he libphonenumber library that support parsing and formatting of phone numbers from/to strings.
PhoneNumberFormat	com.google.i18n.phonenumbers.PhoneNumberUtil.PhoneNumberFormat
AuthConst	ch.nevis.esauth.auth.engine.AuthConst	Helper classes of nevisAuth whose static methods may be invoked like regular bean methods.
CertificateUtil	ch.nevis.esauth.util.CertificateUtil
PwGetter	ch.nevis.esauth.util.PwGetter
ELUtils	ch.nevis.esauth.util.el.ELUtils

Date handling

nevisAuth EL expression rely on the java.time API to parse and do operation on dates. An overview of the java.time API is available in the official documenation.

The table above describes which java.time classes are available in nevisAuth EL expressions.

Standard date formats handled by Java can be found in the official documentation, including formatting.

Visit Appendix J for detailed examples.