Review Request: JDK-8173947: jconsole does not show local running VMs to attach

[Mandy Chung]

sun.management.ConnectorAddressLink is renamed to 
jdk.internal.agent.ConnectorAddressLink but missed the Class.forName call in 
JConsole.  Thanks to Peter catching this regression.  Since jdk.jconsole 
requires jdk.attach and jdk.management.agent that guarantees the classes 
required are present at runtime, so we can drop the Class.forName calls. 

I leave the isLocalAttachAvailable() method there to keep the current 
implementation that supports to run even if the local attach is not supported.

Mandy

diff --git a/src/jdk.jconsole/share/classes/sun/tools/jconsole/JConsole.java 
b/src/jdk.jconsole/share/classes/sun/tools/jconsole/JConsole.java
--- a/src/jdk.jconsole/share/classes/sun/tools/jconsole/JConsole.java
+++ b/src/jdk.jconsole/share/classes/sun/tools/jconsole/JConsole.java
@@ -949,23 +949,12 @@
         }
     }
 
-    private static final boolean localAttachmentSupported;
-    static {
-        boolean supported;
-        try {
-            Class.forName("com.sun.tools.attach.VirtualMachine");
-            Class.forName("sun.management.ConnectorAddressLink");
-            supported = true;
-        } catch (NoClassDefFoundError x) {
-            supported = false;
-        } catch (ClassNotFoundException x) {
-            supported = false;
-        }
-        localAttachmentSupported = supported;
-    }
-
+    /**
+     * local attach is supported in this implementation as jdk.jconsole
+     * requires jdk.attach and jdk.management.agent
+     */
     public static boolean isLocalAttachAvailable() {
-        return localAttachmentSupported;
+        return true;
     }