add -h -help

Author: songlonqi-java

src/main/java/name/dhruba/javaagent/Config.java

@@ -1,5 +1,7 @@
 package name.dhruba.javaagent;
 
+import java.io.PrintStream;
+
 public class Config {
     private String options;
 
@@ -44,9 +46,25 @@ static Config parse(String... args){
                     case "-agent-jar":
                          agentJar = arg;
                         break;
+                    case "-h":
+                    case "-help":
+                        printOut();
+                        break;
+
                 }
             }
         }
         return new Config(option,downloadAddr,agentJar);
     }
+    public static void printOut(){
+        PrintStream out =   System.out;
+        out.println("    java -jar agent-attach-java.jar [-options <dd options>]");
+        out.println("                                    [-agent-jar <agent filepath>]");
+        out.println("                                    [-h]");
+        out.println("                                    [-help]");
+        out.println(" [-options]:");
+        out.println(" this is dd-java-agnet.jar env, example:");
+        out.println("    dd.agent.port=9529,dd.agent.host=localhost,dd.service=serviceName");
+        out.println(" [-agent-jar]:");
+    }
 }

src/main/java/name/dhruba/javaagent/JavaAgentLoader.java

@@ -28,6 +28,7 @@ public static void loadAgent(String agentJar ,String options) {
                     attach.loadAgent(jarFilePath, options);
                 }
                 attach.detach();
+                logger.info(String.format("attach agent into [%s]",virtualMachineDescriptor.displayName()));
             }
         } catch (Exception e) {
             throw new RuntimeException(e);