Classpath urls

pom.xml

@@ -12,8 +12,8 @@
   <properties>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <maven.compiler.source>1.8</maven.compiler.source>
-    <maven.compiler.target>1.8</maven.compiler.target>
+    <maven.compiler.source>9</maven.compiler.source>
+    <maven.compiler.target>9</maven.compiler.target>
   </properties>
 
   <build>

src/main/java/com/stackoverflow/q76848364/ClasspathURLStreamHandlerProvider.java

@@ -0,0 +1,38 @@
+package com.stackoverflow.q76848364;
+
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLStreamHandler;
+import java.net.spi.URLStreamHandlerProvider;
+
+/**
+ * URL stream handler for "cp:/" URLs for accessing resources in the classpath.
+ * Supports a leading slash in the the path so that the scheme is treated as a
+ * hierarchical scheme for resolving relative URL references.
+ * 
+ * <p>
+ * Register this provider by putting the fully qualified name of this class in
+ * the configuration file
+ * META-INF/services/java.net.spi.URLStreamHandlerProvider.
+ */
+public class ClasspathURLStreamHandlerProvider extends URLStreamHandlerProvider {
+
+    private static final String PROTOCOL = "cp";
+
+    @Override
+    public URLStreamHandler createURLStreamHandler(String protocol) {
+        if (PROTOCOL.equals(protocol)) {
+            return new URLStreamHandler() {
+                @Override
+                protected URLConnection openConnection(URL url) throws IOException {
+                    String urlPath = url.getPath();
+                    String resourcePath = urlPath.startsWith("/") ? urlPath.substring(1) : urlPath;
+                    return ClassLoader.getSystemClassLoader().getResource(resourcePath).openConnection();
+                }
+            };
+        }
+        return null;
+    }
+
+}

src/main/resources/META-INF/services/java.net.spi.URLStreamHandlerProvider

@@ -0,0 +1 @@
+com.stackoverflow.q76848364.ClasspathURLStreamHandlerProvider