jdk/test/java/lang/instrument/RedefineClassWithNativeMethodAgent.java
changeset 278 b6cec9b83669
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/instrument/RedefineClassWithNativeMethodAgent.java	Mon Mar 24 16:11:24 2008 -0700
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+import java.lang.instrument.*;
+import java.net.*;
+import java.util.*;
+import java.io.*;
+
+public class RedefineClassWithNativeMethodAgent {
+    static Class clz;
+
+    // just read the original class and redefine it via a Timer
+    public static void premain(String agentArgs, final Instrumentation inst) throws Exception {
+        String s = agentArgs.substring(0, agentArgs.indexOf(".class"));
+        clz = Class.forName(s.replace('/', '.'));
+        ClassLoader loader =
+            RedefineClassWithNativeMethodAgent.class.getClassLoader();
+        URL classURL = loader.getResource(agentArgs);
+        if (classURL == null) {
+            throw new Exception("Cannot find class: " + agentArgs);
+        }
+
+        int         redefineLength;
+        InputStream redefineStream;
+
+        System.out.println("Reading test class from " + classURL);
+        if (classURL.getProtocol().equals("file")) {
+            File f = new File(classURL.getFile());
+            redefineStream = new FileInputStream(f);
+            redefineLength = (int) f.length();
+        } else {
+            URLConnection conn = classURL.openConnection();
+            redefineStream = conn.getInputStream();
+            redefineLength = conn.getContentLength();
+        }
+
+        final byte[] buffer = new byte[redefineLength];
+        new BufferedInputStream(redefineStream).read(buffer);
+        new Timer(true).schedule(new TimerTask() {
+            public void run() {
+                try {
+                    System.out.println("Instrumenting");
+                    ClassDefinition cld = new ClassDefinition(clz, buffer);
+                    inst.redefineClasses(new ClassDefinition[] { cld });
+                }
+                catch (Exception e) { e.printStackTrace(); }
+            }
+        }, 500);
+    }
+}