Retrieve resource bytes from map as URLStreamHandler can be shared to…

… other resources (#1)

Co-authored-by: jose.pereda <[email protected]>

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/Resources.java

@@ -25,6 +25,7 @@
 package com.oracle.svm.core.jdk;
 
 import java.io.ByteArrayInputStream;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
@@ -125,8 +126,26 @@ public static List<byte[]> get(String name) {
 
     public static URL createURL(String name, byte[] resourceBytes) {
         class Conn extends URLConnection {
+
+            private InputStream in;
+            private long length = -1L;
+
             Conn(URL url) {
                 super(url);
+
+                // remove "resource:" from url to get the resource name
+                String resName = url.toString().substring(1 + JavaNetSubstitutions.RESOURCE_PROTOCOL.length());
+                if (resName.equals(name)) {
+                    in = new ByteArrayInputStream(resourceBytes);
+                    length = resourceBytes.length;
+                } else {
+                    final List<byte[]> bytes = singleton().resources.get(resName);
+                    if (bytes != null && !bytes.isEmpty()) {
+                        byte[] resBytes = bytes.get(0);
+                        in = new ByteArrayInputStream(resBytes);
+                        length = resBytes.length;
+                    }
+                }
             }
 
             @Override
@@ -135,17 +154,20 @@ public void connect() throws IOException {
 
             @Override
             public InputStream getInputStream() throws IOException {
-                return new ByteArrayInputStream(resourceBytes);
+                if (in == null) {
+                    throw new FileNotFoundException(url.toString());
+                }
+                return in;
             }
 
             @Override
             public long getContentLengthLong() {
-                return resourceBytes.length;
+                return length;
             }
         }
 
         try {
-            return new URL("resource", null, -1, name, new URLStreamHandler() {
+            return new URL(JavaNetSubstitutions.RESOURCE_PROTOCOL, null, -1, name, new URLStreamHandler() {
                 @Override
                 protected URLConnection openConnection(URL u) throws IOException {
                     return new Conn(u);