nashorn/samples/jd.js
changeset 28318 bcfb5663e81a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/samples/jd.js	Wed Jan 07 14:02:30 2015 +0530
@@ -0,0 +1,94 @@
+#// Usage: jjs -cp <asmtools.jar> jd.js -- <classname> [jdis|jdec]
+
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// javap-like disassembler/decoder tool that disassembles/decodes 
+// java classes but with OpenJDK AsmTools disassembler/decoder syntax.
+// You need to build asmtool.jar from OpenJDK codetools project
+// specify it with -cp option.
+
+// See also https://wiki.openjdk.java.net/display/CodeTools/AsmTools
+
+function usage() {
+    print("Usage: jjs -cp <asmtools.jar> jd.js -- <classname> [jdis|jdec]");
+    exit(1);
+}
+
+if (arguments.length == 0) {
+    usage();
+}
+
+// argument handling
+// convert to internal class name
+var className = arguments[0].replaceAll('\\.', '/');
+var tool;
+if (arguments.length > 1) {
+    tool = arguments[1];
+    switch (tool) {
+        case 'jdis':
+        case 'jdec':
+            break;
+        default:
+            usage();
+    }
+} else {
+    tool = "jdis"; // default tool
+}
+
+// Java classes used
+var AsmTools = Java.type("org.openjdk.asmtools.Main");
+var Files = Java.type("java.nio.file.Files");
+var StandardCopyOption = Java.type("java.nio.file.StandardCopyOption");
+
+// retrive input stream for .class bytes
+var cl = AsmTools.class.classLoader;
+var res = cl.getResource(className + ".class");
+
+if (res) {
+    var is = res.openStream();
+    var tmpPath;
+    try {
+        // copy the content of the .class to a temp file
+        tmpPath = Files.createTempFile("asmtools-", ".class");
+        // mark as delete-on-exit
+        tmpPath.toFile().deleteOnExit();
+        Files.copy(is, tmpPath, [ StandardCopyOption.REPLACE_EXISTING ]);
+    } finally {
+        is.close();
+    } 
+
+    // invoke asmtools Main
+    AsmTools.main([ tool, tmpPath.toString() ]);
+} else {
+    print("no such class: " + arguments[0]);
+    exit(1);
+}