Package org.apache.juneau.rest.server.staticfile

Class WebJarResolver

java.lang.Object

org.apache.juneau.rest.server.staticfile.WebJarResolver

public final class WebJarResolver
extends Object

Resolves a WebJar file to a cache-busted URL under the WebJarsMixin mount.

An asset is named groupId:artifactId:path (see asset(String, String, String)). The path is relative to META-INF/resources/webjars/ and may contain VERSION_TOKEN, which is replaced with the version read from the WebJar's own META-INF/maven/<groupId>/<artifactId>/pom.properties. The URL gets a ?v=<version> cache-buster, so a version bump in the app's pom changes every URL.

A missing WebJar, or a missing file in a present WebJar, throws IllegalStateException, so a page never renders a tag that would 404. Versions and file checks are cached for the life of the class loader.

Example:

String asset = WebJarResolver.asset("org.webjars", "jquery", "jquery/{version}/jquery.min.js"); String url = WebJarResolver.resolve(req, asset); // .../webjars/jquery/3.7.1/jquery.min.js?v=3.7.1

Since:

10.0.0

Field Summary

Fields

Modifier and Type	Field	Description
static final String	VERSION_TOKEN	Placeholder in an asset path that is replaced with the WebJar's version.
static final String	WEBJARS_ROOT	Classpath root of every WebJar's files.

Method Summary

Modifier and Type	Method	Description
static String	asset(String groupId, String artifactId, String path)	Builds an asset id.
static String	resolve(RestRequest req, String asset)	Resolves an asset id to an absolute, cache-busted URL under the WebJarsMixin mount of the request's servlet.
static String	resolvePath(String asset)	Resolves an asset id to its file path under META-INF/resources/webjars/, checking that the file exists.
static String	version(String groupId, String artifactId)	Returns the version of a WebJar on the classpath.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

WEBJARS_ROOT

public static final String WEBJARS_ROOT

Classpath root of every WebJar's files.

See Also:

• Constant Field Values

VERSION_TOKEN

public static final String VERSION_TOKEN

Placeholder in an asset path that is replaced with the WebJar's version.

See Also:

• Constant Field Values

Method Details

asset

public static String asset(String groupId,
 String artifactId,
 String path)

Builds an asset id.

Parameters:

groupId - The WebJar group id, e.g. org.webjars.

artifactId - The WebJar artifact id, e.g. jquery.

path - The file path under META-INF/resources/webjars/, optionally containing VERSION_TOKEN.

Returns:

The asset id groupId:artifactId:path.

version

public static String version(String groupId,
 String artifactId)

Returns the version of a WebJar on the classpath.

Parameters:

groupId - The WebJar group id.

artifactId - The WebJar artifact id.

Returns:

The version from the WebJar's pom.properties.

Throws:

IllegalStateException - If the WebJar isn't on the classpath or names no version.

resolvePath

public static String resolvePath(String asset)

Resolves an asset id to its file path under META-INF/resources/webjars/, checking that the file exists.

Parameters:

asset - The asset id (see asset(String, String, String)).

Returns:

The path with VERSION_TOKEN filled in.

Throws:

IllegalArgumentException - If the asset id is malformed.

IllegalStateException - If the WebJar or the file isn't on the classpath.

resolve

public static String resolve(RestRequest req,
 String asset)

Resolves an asset id to an absolute, cache-busted URL under the WebJarsMixin mount of the request's servlet.

Parameters:

req - The in-flight request.

asset - The asset id (see asset(String, String, String)).

Returns:

The URL.