Add self-extracting jar utility

2019-10-16 14:23:39 -07:00
parent bb79221cfe
commit 28971de511
8 changed files with 255 additions and 0 deletions
--- a/self-extracting-jar-creator/src/main/java/SelfExtractor.java
+++ b/self-extracting-jar-creator/src/main/java/SelfExtractor.java
@@ -0,0 +1,132 @@
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.URL;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+import java.util.zip.ZipOutputStream;
+
+
+/**
+ * SelfExtractor
+ */
+public class SelfExtractor {
+
+	private static final String CONTENTS_ZIP_RSRC = "/contents.zip";
+	private static final int BUF_SIZE = 1024*8;
+
+	byte[] buffer = new byte[BUF_SIZE];
+
+	public static void main(String[] args) throws Exception {
+		new SelfExtractor().run(args);
+	}
+
+	private void run(String[] args) throws Exception {
+		if (args.length==0) {
+			unpack();
+		} else if (args.length==1) {
+			repack(args[0]);
+		} else {
+			throw new IllegalArgumentException("Expecting one argument pointing to zipfile to re-wrap");
+		}
+	}
+
+	private void repack(String _contentsZip) throws Exception {
+		File contentsZip = new File(_contentsZip);
+		System.out.println("Repackaging "+contentsZip);
+		if (!contentsZip.isFile()) {
+			throw new IllegalArgumentException("File not found:" + contentsZip);
+		}
+		String repackagedPath = contentsZip.toString();
+		if (repackagedPath.endsWith(".zip")) {
+			repackagedPath = repackagedPath.substring(0, repackagedPath.length()-4);
+		}
+		repackagedPath = repackagedPath + ".self-extracting.jar";
+		System.out.println("         as "+repackagedPath);
+		
+		File wrapperJar = getMyJar();
+		System.out.println("wrapperJar = "+wrapperJar);
+		try (ZipInputStream zipIn = new ZipInputStream(new FileInputStream(wrapperJar))) {
+			try (ZipOutputStream zipOut = new ZipOutputStream(new FileOutputStream(new File(repackagedPath)))) {
+				ZipEntry entry;
+				while ((entry = zipIn.getNextEntry())!=null) {
+					System.out.println("Adding: "+entry.getName());
+					if (entry.getName().equals("contents.zip")) {
+						//skip. We need to write the wrapped zip contents here.
+					} else {
+						zipOut.putNextEntry(new ZipEntry(entry));
+						if (entry.getName().endsWith("/")) {
+							//skip directory has no bytes as contents
+						} else {
+							copy(zipIn, zipOut);
+						}
+					}
+				} //end while
+				entry = new ZipEntry("contents.zip");
+				zipOut.putNextEntry(entry);
+				System.out.println("Adding: "+entry.getName());
+				try (FileInputStream contentsZipIn = new FileInputStream(contentsZip)) {
+					copy(contentsZipIn, zipOut);
+				}
+			} //end: zipOut
+		}//end: zipIn
+	}
+
+	private void copy(InputStream in, OutputStream out) throws IOException {
+		int bytesRead;
+		while ((bytesRead = in.read(buffer)) > 0) {
+			out.write(buffer, 0, bytesRead);
+		}
+	}
+
+	private File getMyJar() {
+		Class<?> myklass = this.getClass();
+		String resourceName = this.getClass().getName() + ".class";
+        URL resource = myklass.getResource(resourceName);
+        String myResourceUrl = resource.toString();
+        //Example: jar:file:/home/.../self-extracing-jar-creator-0.0.1-SNAPSHOT.jar!/SelfExtractor.class 
+        if (!myResourceUrl.startsWith("jar:file:")) {
+        	File devJar = new File("target/self-extracing-jar-creator-0.0.1-SNAPSHOT.jar");
+        	if (devJar.isFile()) {
+        		return devJar;
+        	}
+    		throw new IllegalStateException("To create self extracting jar, you must run this code from a jar");
+        }
+        return new File(myResourceUrl.substring("jar:file:".length(), myResourceUrl.indexOf('!')));
+    }
+	
+	private ZipInputStream openContentsZip() {
+		InputStream zip = this.getClass().getResourceAsStream(CONTENTS_ZIP_RSRC);
+		if (zip==null) {
+			throw new IllegalArgumentException("Couldn't find embedded '"+CONTENTS_ZIP_RSRC+"");
+		}
+		return new ZipInputStream(zip);
+	}
+
+	public void unpack() throws Exception {
+		File destDir = new File(System.getProperty("user.dir"));
+		try (ZipInputStream zip = openContentsZip()) {
+			ZipEntry entry;
+			while ((entry = zip.getNextEntry())!=null) {
+				String name = entry.getName();
+				System.out.println(name);
+				File outfile = new File(destDir, name);
+				if (outfile.exists()) {
+					throw new IllegalArgumentException("File already exists: "+outfile);
+				}
+				if (name.endsWith("/")) {
+					outfile.mkdirs();
+				} else {
+					//file
+					outfile.getParentFile().mkdirs();
+					try (FileOutputStream out = new FileOutputStream(outfile)) {
+						copy(zip, out);
+					}
+				}
+			}
+		}
+	}
+}