- Made the script use curl or wget if available and fallback to java in case none of them are.

- Moved the Java source code to the filesystem.

maven-wrapper/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,38 @@
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+
+public class MavenWrapperDownloader {
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        String url="http://central.maven.org/maven2/io/takari/maven-wrapper/0.2.1/maven-wrapper-0.2.1.jar";
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+        File outputFile = new File(baseDirectory.getAbsolutePath(), ".mvn/wrapper/maven-wrapper.jar");
+        if(!outputFile.getParentFile().exists()) {
+            outputFile.getParentFile().mkdirs();
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    public static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

maven-wrapper/mvnw

@@ -200,69 +200,43 @@ if [ -z "$BASE_DIR" ]; then
   exit 1;
 fi
 
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+
+JAR_URL="http://central.maven.org/maven2/io/takari/maven-wrapper/0.2.1/maven-wrapper-0.2.1.jar"
 if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
     echo "Found .mvn/wrapper/maven-wrapper.jar"
 else
     echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
-
+    if which wget >/dev/null; then
-    javaClass="/tmp/MavenWrapperDownloader.java"
+        echo "Found wget ... using wget"
-    if [ ! -e "$javaClass" ]; then
+        wget ‐‐output-document=.mvn/wrapper/maven-wrapper.jar "$JAR_URL"
-        echo " - Generating MavenWrapperDownloader.java ..."
+    elif which curl >/dev/null; then
-        # Generating downloader application java class ...
+        echo "Found curl ... using curl"
-        cat <<EOF >"$javaClass"
+        curl -o .mvn/wrapper/maven-wrapper.jar "$JAR_URL"
-import java.net.*;
+    else
-import java.io.*;
+        echo "Falling back to using Java to download"
-import java.nio.channels.*;
+        javaClass=".mvn/wrapper/MavenWrapperDownloader.java"
-
+        if [ -e "$javaClass" ]; then
-public class MavenWrapperDownloader {
+            if [ ! -e ".mvn/wrapper/MavenWrapperDownloader.class" ]; then
-
-    public static void main(String args[]) {
-        System.out.println("- Downloader started");
-        String url="http://central.maven.org/maven2/io/takari/maven-wrapper/0.2.1/maven-wrapper-0.2.1.jar";
-        File baseDirectory = new File(args[0]);
-        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
-        File outputFile = new File(baseDirectory.getAbsolutePath(), ".mvn/wrapper/maven-wrapper.jar");
-        if(!outputFile.getParentFile().exists()) {
-            outputFile.getParentFile().mkdirs();
-        }
-        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
-        try {
-            downloadFileFromURL(url, outputFile);
-            System.out.println("Done");
-            System.exit(0);
-        } catch (Throwable e) {
-            System.out.println("- Error downloading");
-            e.printStackTrace();
-            System.exit(1);
-        }
-    }
-
-    public static void downloadFileFromURL(String urlString, File destination) throws Exception {
-        URL website = new URL(urlString);
-        ReadableByteChannel rbc;
-        rbc = Channels.newChannel(website.openStream());
-        FileOutputStream fos = new FileOutputStream(destination);
-        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
-        fos.close();
-        rbc.close();
-    }
-
-}
-EOF
-    fi
-
-    classFile=$(dirname "$javaClass")/MavenWrapperDownloader.class
-    if [ ! -e "$classFile" ]; then
                 echo " - Compiling MavenWrapperDownloader.java ..."
                 # Compiling the Java class
                 ("$JAVA_HOME/bin/javac" "$javaClass")
             fi
-
+            if [ -e ".mvn/wrapper/MavenWrapperDownloader.class" ]; then
                 # Running the downloader
                 echo " - Running MavenWrapperDownloader.java ..."
-    echo "$MAVEN_PROJECTBASEDIR"
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
-    ("$JAVA_HOME/bin/java" -cp /tmp MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
             fi
+        fi
+    fi
+fi
+
+##########################################################################################
+# End of extension
+##########################################################################################
 
 export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
 if [ "$MVNW_VERBOSE" = true ]; then