admin@glassfish.java.net

Re: how to document properties for _at_Configured items (PROPOSAL)

From: Jerome Dochez <Jerome.Dochez_at_Sun.COM>
Date: Fri, 17 Oct 2008 21:58:05 -0700

I like it, some remarks :

1. why is the annotation placed at the class level, shouldn't the field
List<Property> be annotated instead
2. doing field annotation would remove the need to SystemPropertiesDesc
since you would just annotate List<Property> systemProperties
3. for description(), I would encourage for some i18n where instead of
an english description, we could reference a LocalString.properties
element. This would allow us to generate localized @Configured
documentation.
4. is this a pure documentation play or should we push runtime enforcement ?
5. I would question the "required()" boolean, I think AFAIK, there are
no required properties and if there are, maybe we should move them to
real attribute or element.

Lloyd Chambers wrote:
> Team,
>
> I just finished going through "Sun GlassFish Enterprise Server v3
> Prelude Administration Reference". It took a lot of "eyeball work"
> going through every page, and each and every interface--this is error
> prone and hard to maintain.
>
> Many properties and system properties are documented in the reference,
> yet none of them are documented in the @Configured interfaces--at
> all. This stands in stark contrast to attributes and elements, which
> are naturally javadoc'd.
>
> Several other issues come to mind for properties (eg <property> and
> <system-property>):
> - no formal mechanism to document the legal properties (except
> free-form javadoc comments, none there as yet);
> - impossible to validate property names or values;
> - cannot warn the user if an unknown or mis-spelled property is being
> used (eg "readerThreads" instead of "reader-threads");
> - documentation for public API is not possible; there is nothing to
> generate it from;
> - no way for dependent interfaces (eg AMX) to validate or provide
> metadata.
>
> --- PROPOSAL ---
>
> 1) Add annotations to describe the legal properties and system
> properties;
> 2) Add these annotations on all the @Configured interfaces which have
> properties;
> 3) Encourage developers to maintain the annotations.
>
> Below is an example of how this would work for @Configured
> HttpListener. One alternative would be to define a "sidecar" class
> that has "public static final String" variables for each property, and
> annotate each of those individually.
>
> Note that because there cannot be more than one annotation of a given
> type, a grouping annotation is used to allow annotations for every
> property. See annotation classes further below.
>
> @PropertiesDesc({
> @PropertyDesc(name="recycle-objects", defaultValue="true",
> dataType=Boolean.class),
> @PropertyDesc(name="reader-threads", defaultValue="0",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="acceptor-queue-length", defaultValue="4096",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="reader-queue-length", defaultValue="4096",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="use-nio-direct-bytebuffer",
> defaultValue="false", dataType=Boolean.class),
> @PropertyDesc(name="authPassthroughEnabled", defaultValue="false",
> dataType=Boolean.class),
> @PropertyDesc(name="proxyHandler",
> defaultValue="com.sun.enterprise.web.ProxyHandlerImpl"),
> @PropertyDesc(name="proxiedProtocol", values={"ws/tcp", "http",
> "https", "tls"}),
> @PropertyDesc(name="bufferSize", defaultValue="4096",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="connectionTimeout", defaultValue="30",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="maxKeepAliveRequests", defaultValue="250",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="traceEnabled", defaultValue="true",
> dataType=Boolean.class),
> @PropertyDesc(name="cometSupport", defaultValue="false",
> dataType=Boolean.class),
> @PropertyDesc(name="jkEnabled", defaultValue="false",
> dataType=Boolean.class),
> @PropertyDesc(name="compression", defaultValue="off",
> values={"off","on","force"}),
> @PropertyDesc(name="compressableMimeType",
> defaultValue="text/html, text/xml, text/plain"),
> @PropertyDesc(name="noCompressionUserAgents", defaultValue=""),
> @PropertyDesc(name="compressionSize",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="minCompressionSize",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="crlFile"),
> @PropertyDesc(name="trustAlgorithm", values="PKIX"),
> @PropertyDesc(name="trustMaxCertLength", defaultValue="5",
> dataType=Integer.class),
> @PropertyDesc(name="disableUploadTimeout", defaultValue="true",
> dataType=Boolean.class),
> @PropertyDesc(name="connectionUploadTimeout", defaultValue="5",
> dataType=NonNegativeInteger.class),
> @PropertyDesc(name="uriEncoding", defaultValue="UTF-8",
> values={"UTF-8"})
> })
>
> @AMXConfigInfo(
> amxInterfaceName="com.sun.appserv.management.config.HTTPListenerConfig")
> @Configured
> public interface HttpListener extends ConfigBeanProxy, Injectable,
> PropertyBag {
>
> ...
> }
>
> ---
>
> /**
> * Describes properties or system properties that might exist as
> sub-elements.
> */
> @Retention(RUNTIME)
> @Target({TYPE})
> public @interface PropertyDesc {
> /** name of the property */
> String name();
>
> /** default value of the property */
> String defaultValue() default "\u0000";
>
> /** freeform description */
> String description() default "\u0000";
>
> /** Indicates that this property is required (rare) */
> boolean required() default false;
>
> /** the DataType class, can be Class<? extends {_at_link DataType}>
> or String.class */
> Class dataType() default String.class;
>
> /** Possible values, might not be a complete list and/or there
> could be other alternatives
> such as specific numbers, variables, etc.
> */
> String[] values();
> }
>
>
> /**
> * Annotation that holds an array of {_at_link PropertyDesc} for system
> properties eg {_at_link SystemProperty}.
> * Needed because it's not otherwise possible to have more than one
> annotation of the same type.
> */
> @Retention(RUNTIME)
> @Target({TYPE,METHOD})
> public @interface SystemPropertiesDesc {
> /** name of the property */
> PropertyDesc[] value();
> }
>
> /**
> * Annotation that holds an array of {_at_link PropertyDesc} for
> properties eg {_at_link Property}.
> * Needed because it's not otherwise possible to have more than one
> annotation of the same type.
> */
> @Retention(RUNTIME)
> @Target({TYPE,METHOD})
> public @interface PropertiesDesc {
> /** name of the property */
> PropertyDesc[] value();
> }
>
>
>
>
> ..............................................
> Lloyd Chambers
> lloyd.chambers_at_sun.com
> GlassFish team, LSARC member
>
>
>
>
>
>