improving the way to locate agent and registering web app

microsoft · Mar 16, 2018 · bc19586 · bc19586
1 parent 4bd0b4b
commit bc19586
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Showing 2 changed files with 43 additions and 40 deletions.
diff --git a/core/src/main/java/com/microsoft/applicationinsights/common/CommonUtils.java b/core/src/main/java/com/microsoft/applicationinsights/common/CommonUtils.java
@@ -22,30 +22,44 @@
 package com.microsoft.applicationinsights.common;
 
 import com.microsoft.applicationinsights.internal.logger.InternalLogger;
-import org.apache.commons.lang3.exception.ExceptionUtils;
-
 import java.net.InetAddress;
 import java.net.UnknownHostException;
+import org.apache.commons.lang3.exception.ExceptionUtils;
 
-
-/**
- * Created by oriy on 11/2/2016.
- */
+/** Created by oriy on 11/2/2016. */
 public class CommonUtils {
-    public static boolean isNullOrEmpty(String string) {
-        return string == null || string.length() == 0;
+  public static boolean isNullOrEmpty(String string) {
+    return string == null || string.length() == 0;
+  }
+
+  public static String getHostName() {
+    try {
+      InetAddress addr;
+      addr = InetAddress.getLocalHost();
+      return addr.getCanonicalHostName();
+    } catch (UnknownHostException ex) {
+      // optional parameter. do nothing if unresolvable
+      InternalLogger.INSTANCE.trace(
+          "Unresolvable host error. Stack trace generated is %s", ExceptionUtils.getStackTrace(ex));
+      return null;
     }
-    public static String getHostName(){
-        try
-        {
-            InetAddress addr;
-            addr = InetAddress.getLocalHost();
-            return addr.getCanonicalHostName();
-        }
-        catch (UnknownHostException ex) {
-            // optional parameter. do nothing if unresolvable
-            InternalLogger.INSTANCE.trace("Unresolvable host error. Stack trace generated is %s", ExceptionUtils.getStackTrace(ex));
-            return null;
-        }
+  }
+
+  /**
+   * This method is used to test if the given class is loaded in the specified ClassLoader
+   * @param classSignature Fully Qualified signature of class
+   * @param classLoader ClassLoader under consideration
+   * @return true if class is loaded otherwise false
+   */
+  public static boolean isClassPresentOnClassPath(String classSignature, ClassLoader classLoader) {
+
+    try {
+      Class.forName(classSignature, false, classLoader);
+      return true;
+    } catch (ClassNotFoundException e) {
+      InternalLogger.INSTANCE.info(
+          "Specified class %s is not present on the classpath", classSignature);
+      return false;
     }
+  }
 }
diff --git a/...rc/main/java/com/microsoft/applicationinsights/web/internal/WebRequestTrackingFilter.java b/...rc/main/java/com/microsoft/applicationinsights/web/internal/WebRequestTrackingFilter.java
@@ -62,6 +62,8 @@ public final class WebRequestTrackingFilter implements Filter {
     private boolean agentIsUp = false;
     private final LinkedList<ThreadLocalCleaner> cleaners = new LinkedList<ThreadLocalCleaner>();
     private String appName;
+    private static final String AGENT_LOCATOR_INTERFACE_NAME = "com.microsoft.applicationinsights."
+        + "agent.internal.coresync.AgentNotificationsHandler";
 
     // endregion Members
 
@@ -230,33 +232,20 @@ public WebRequestTrackingFilter() {
     }
 
     private synchronized void initialize(FilterConfig filterConfig) {
-        try {
 
-            //if agent is not installed (jar not loaded), can skip the entire registration process
-            try {
-                AgentConnector test = AgentConnector.INSTANCE;
-            } catch (ThreadDeath td) {
-                throw td;
-            } catch (Throwable t) {
-                try {
-                    InternalLogger.INSTANCE.info("Agent was not found. Skipping the agent registration");
-                    return;
-                } catch (ThreadDeath td) {
-                    throw td;
-                } catch (Throwable t2) {
-                    // chomp
-                }
-            }
+        //If Agent Jar is not present in the class path skip the process
+        if (!CommonUtils.isClassPresentOnClassPath(AGENT_LOCATOR_INTERFACE_NAME,
+            this.getClass().getClassLoader())) {
+            InternalLogger.INSTANCE.info("Agent was not found. Skipping the agent registration");
+            return;
+        }
 
+        try {
             ServletContext context = filterConfig.getServletContext();
-
             String name = getName(context);
-
             String key = registerWebApp(appName);
             setKey(key);
-
             InternalLogger.INSTANCE.info("Successfully registered the filter '%s'", FILTER_NAME);
-
         } catch (ThreadDeath td) {
             throw td;
         } catch (Throwable t) {