< prev index next > src/java.base/share/classes/jdk/internal/jimage/ImageReader.java
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public Node findNode(String name) throws IOException {
ensureOpen();
return reader.findNode(name);
}
+ /**
+ * Returns a resource node in the given module, or null if no resource of
+ * that name exists.
+ *
+ * <p>This is equivalent to:
+ * <pre>{@code
+ * findNode("/modules/" + moduleName + "/" + resourcePath)
+ * }</pre>
+ * but more performant, and returns {@code null} for directories.
+ *
+ * @param moduleName The module name of the requested resource.
+ * @param resourcePath Trailing module-relative resource path, not starting
+ * with {@code '/'}.
+ */
+ public Node findResourceNode(String moduleName, String resourcePath)
+ throws IOException {
+ ensureOpen();
+ return reader.findResourceNode(moduleName, resourcePath);
+ }
+
+ /**
+ * Returns whether a resource exists in the given module.
+ *
+ * <p>This is equivalent to:
+ * <pre>{@code
+ * findResourceNode(moduleName, resourcePath) != null
+ * }</pre>
+ * but more performant, and will not create or cache new nodes.
+ *
+ * @param moduleName The module name of the resource being tested for.
+ * @param resourcePath Trailing module-relative resource path, not starting
+ * with {@code '/'}.
+ */
+ public boolean containsResource(String moduleName, String resourcePath)
+ throws IOException {
+ ensureOpen();
+ return reader.containsResource(moduleName, resourcePath);
+ }
+
/**
* Returns a copy of the content of a resource node. The buffer returned by
* this method is not cached by the node, and each call returns a new array
* instance.
*
/**
* Returns a node with the given name, or null if no resource or directory of
* that name exists.
*
! * <p>This is the only public API by which anything outside this class can access
- * {@code Node} instances either directly, or by resolving symbolic links.
- *
- * <p>Note also that there is no reentrant calling back to this method from within
* the node handling code.
*
* @param name an absolute, {@code /}-separated path string, prefixed with either
* "/modules" or "/packages".
*/
/**
* Returns a node with the given name, or null if no resource or directory of
* that name exists.
*
! * <p>Note that there is no reentrant calling back to this method from within
* the node handling code.
*
* @param name an absolute, {@code /}-separated path string, prefixed with either
* "/modules" or "/packages".
*/
Node node = nodes.get(name);
if (node == null) {
// We cannot get the root paths ("/modules" or "/packages") here
// because those nodes are already in the nodes cache.
if (name.startsWith(MODULES_ROOT + "/")) {
+ // This may perform two lookups, one for a directory (in
+ // "/modules/...") and one for a non-prefixed resource
+ // (with "/modules" removed).
node = buildModulesNode(name);
} else if (name.startsWith(PACKAGES_ROOT + "/")) {
node = buildPackagesNode(name);
}
if (node != null) {
}
assert node == null || node.isCompleted() : "Incomplete node: " + node;
return node;
}
+ /**
+ * Returns a resource node in the given module, or null if no resource of
+ * that name exists.
+ *
+ * <p>Note that there is no reentrant calling back to this method from within
+ * the node handling code.
+ */
+ Node findResourceNode(String moduleName, String resourcePath) {
+ // Unlike findNode(), this method makes only one lookup in the
+ // underlying jimage, but can only reliably return resource nodes.
+ if (moduleName.indexOf('/') >= 0) {
+ throw new IllegalArgumentException("invalid module name: " + moduleName);
+ }
+ String nodeName = MODULES_ROOT + "/" + moduleName + "/" + resourcePath;
+ // Synchronize as tightly as possible to reduce locking contention.
+ synchronized (this) {
+ Node node = nodes.get(nodeName);
+ if (node == null) {
+ ImageLocation loc = findLocation(moduleName, resourcePath);
+ if (loc != null && isResource(loc)) {
+ node = newResource(nodeName, loc);
+ nodes.put(node.getName(), node);
+ }
+ return node;
+ } else {
+ return node.isResource() ? node : null;
+ }
+ }
+ }
+
+ /**
+ * Returns whether a resource exists in the given module.
+ *
+ * <p>This method is expected to be called frequently for resources
+ * which do not exist in the given module (e.g. as part of classpath
+ * search). As such, it skips checking the nodes cache and only checks
+ * for an entry in the jimage file, as this is faster if the resource
+ * is not present. This also means it doesn't need synchronization.
+ */
+ boolean containsResource(String moduleName, String resourcePath) {
+ if (moduleName.indexOf('/') >= 0) {
+ throw new IllegalArgumentException("invalid module name: " + moduleName);
+ }
+ // If the given module name is 'modules', then 'isResource()'
+ // returns false to prevent false positives.
+ ImageLocation loc = findLocation(moduleName, resourcePath);
+ return loc != null && isResource(loc);
+ }
+
/**
* Builds a node in the "/modules/..." namespace.
*
* <p>Called by {@link #findNode(String)} if a {@code /modules/...} node
* is not present in the cache.
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