Improvements to Grails Wrapper JAR

* Fixes #7
* Update Grails Artifactory URL to HTTPS
* Flexibility to override Grails Artifactory base URL via SystemProperty or Environment variable.

Author: puneetbehl

starter/src/main/java/grails/init/Start.java

@@ -10,8 +10,10 @@
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.lang.reflect.Method;
 import java.net.Authenticator;
+import java.net.HttpURLConnection;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.nio.channels.Channels;
@@ -24,17 +26,31 @@
 public class Start {
 
     private static final String PROJECT_NAME = "grails-wrapper";
-    private static final String BASE_URL = "http://repo.grails.org/grails/core/org/grails/" + PROJECT_NAME;
+    private static final String WRAPPER_PATH = "/org/grails/" + PROJECT_NAME;
+    private static final String DEFAULT_GRAILS_CORE_ARTIFACTORY_BASE_URL = "https://repo.grails.org/grails/core";
     private static final File WRAPPER_DIR = new File(System.getProperty("user.home") + "/.grails/wrapper");
     private static final File NO_VERSION_JAR = new File(WRAPPER_DIR, PROJECT_NAME + ".jar");
 
-    private static String getVersion() throws SAXException, ParserConfigurationException {
+    private static String getGrailsCoreArtifactoryBaseUrl() {
+        String baseUrl = System.getProperty("grails.core.artifactory.baseUrl");
+        if (baseUrl != null) {
+            return baseUrl;
+        }
+        baseUrl = System.getenv("GRAILS_CORE_ARTIFACTORY_BASE_URL");
+        if (baseUrl != null) {
+            return baseUrl;
+        }
+        return DEFAULT_GRAILS_CORE_ARTIFACTORY_BASE_URL;
+    }
+
+    private static String getVersion() {
         try {
             SAXParserFactory factory = SAXParserFactory.newInstance();
             SAXParser saxParser = factory.newSAXParser();
             FindReleaseHandler findReleaseHandler = new FindReleaseHandler();
-            saxParser.parse(new URL(BASE_URL + "/maven-metadata.xml").openStream(), findReleaseHandler);
-
+            final String mavenMetadataFileUrl = getGrailsCoreArtifactoryBaseUrl() + WRAPPER_PATH + "/maven-metadata.xml";
+            HttpURLConnection conn = createHttpURLConnection(mavenMetadataFileUrl);
+            saxParser.parse(conn.getInputStream(), findReleaseHandler);
             return findReleaseHandler.getVersion();
         } catch (Exception e) {
             if (!NO_VERSION_JAR.exists()) {
@@ -46,6 +62,13 @@ private static String getVersion() throws SAXException, ParserConfigurationExcep
         }
     }
 
+    private static HttpURLConnection createHttpURLConnection(String mavenMetadataFileUrl) throws IOException {
+        final URL url = new URL(mavenMetadataFileUrl);
+        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
+        conn.setInstanceFollowRedirects(true);
+        return conn;
+    }
+
 
     private static boolean updateJar(String version) {
 
@@ -57,25 +80,28 @@ private static boolean updateJar(String version) {
         WRAPPER_DIR.mkdirs();
 
         try {
-            File dowloadedJar = File.createTempFile(jarFileName, jarFileExtension);
-
-            URL website = new URL(BASE_URL + "/" + version + "/" + jarFileName + jarFileExtension);
-            ReadableByteChannel rbc = Channels.newChannel(website.openStream());
-            FileOutputStream fos = new FileOutputStream(dowloadedJar);
-            fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
-            fos.close();
-
-            Files.move(dowloadedJar.getAbsoluteFile().toPath(), NO_VERSION_JAR.getAbsoluteFile().toPath(), REPLACE_EXISTING);
+            File downloadedJar = File.createTempFile(jarFileName, jarFileExtension);
 
-            success = true;
-        } catch(Exception e) {
+            final String wrapperUrl = getGrailsCoreArtifactoryBaseUrl() + WRAPPER_PATH + "/" + version + "/" + jarFileName + jarFileExtension;
+            HttpURLConnection conn = createHttpURLConnection(wrapperUrl);
+            success = downloadWrapperJar(downloadedJar, conn.getInputStream());
+        } catch (Exception e) {
             System.out.println("There was an error downloading the wrapper jar");
             e.printStackTrace();
         }
 
         return success;
     }
 
+    private static boolean downloadWrapperJar(File downloadedJar, InputStream inputStream) throws IOException {
+        ReadableByteChannel rbc = Channels.newChannel(inputStream);
+        try (FileOutputStream fos = new FileOutputStream(downloadedJar)) {
+            fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        }
+        Files.move(downloadedJar.getAbsoluteFile().toPath(), NO_VERSION_JAR.getAbsoluteFile().toPath(), REPLACE_EXISTING);
+        return true;
+    }
+
     public static void main(String[] args) {
         Authenticator.setDefault(new SystemPropertiesAuthenticator());
 
@@ -115,16 +141,16 @@ public static void main(String[] args) {
                                 if (outputStream != null) {
                                     outputStream.close();
                                 }
-                            }
+            }
                         }
                     }
                 }
             }
 
-            URLClassLoader child = new URLClassLoader(new URL[] {NO_VERSION_JAR.toURI().toURL()});
+            URLClassLoader child = new URLClassLoader(new URL[]{NO_VERSION_JAR.toURI().toURL()});
             Class classToLoad = Class.forName("grails.init.RunCommand", true, child);
             Method main = classToLoad.getMethod("main", String[].class);
-            main.invoke(null, (Object)args);
+            main.invoke(null, (Object) args);
 
         } catch (Exception e) {
             e.printStackTrace();