Merge pull request #141 from launchdarkly/eb/ch57521/newrelic-class

fix NewRelic reflection logic to avoid shading

packaging-test/test-app/src/main/java/com/launchdarkly/shaded/com/newrelic/api/agent/NewRelic.java

@@ -0,0 +1,9 @@
+package com.launchdarkly.shaded.com.newrelic.api.agent;
+
+// Test to verify fix for https://github.com/launchdarkly/java-server-sdk/issues/171
+public class NewRelic {
+  public static void addCustomParameter(String name, String value) {
+    System.out.println("NewRelic class reference was shaded! Test app loaded " + NewRelic.class.getName());
+    System.exit(1); // forces test failure
+  }	
+}

packaging-test/test-app/src/main/java/com/newrelic/api/agent/NewRelic.java

@@ -0,0 +1,8 @@
+package com.newrelic.api.agent;
+
+// Test to verify fix for https://github.com/launchdarkly/java-server-sdk/issues/171
+public class NewRelic {
+  public static void addCustomParameter(String name, String value) {
+    System.out.println("NewRelic class reference was correctly resolved without shading");
+  }	
+}

packaging-test/test-app/src/main/java/testapp/TestApp.java

@@ -18,6 +18,9 @@ public static void main(String[] args) throws Exception {
     // that provides its own copy of Gson).
     JsonPrimitive x = new JsonPrimitive("x");
 
+    // Also do a flag evaluation, to ensure that it calls NewRelicReflector.annotateTransaction()
+    client.boolVariation("flag-key", new LDUser("user-key"), false);
+
     System.out.println("@@@ successfully created LD client @@@");
   }
 }

src/main/java/com/launchdarkly/client/NewRelicReflector.java

@@ -1,5 +1,7 @@
 package com.launchdarkly.client;
 
+import com.google.common.base.Joiner;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -13,17 +15,24 @@ final class NewRelicReflector {
 
   private static final Logger logger = LoggerFactory.getLogger(NewRelicReflector.class);
 
-
   static {
     try {
-      newRelic = Class.forName("com.newrelic.api.agent.NewRelic");
+      newRelic = Class.forName(getNewRelicClassName());
       addCustomParameter = newRelic.getDeclaredMethod("addCustomParameter", String.class, String.class);
     } catch (ClassNotFoundException | NoSuchMethodException e) {
       logger.info("No NewRelic agent detected");
     }
   }
 
-   static void annotateTransaction(String featureKey, String value) {
+  static String getNewRelicClassName() {
+    // This ungainly logic is a workaround for the overly aggressive behavior of the Shadow plugin, which
+    // will transform any class or package names passed to Class.forName() if they are string literals;
+    // it will even transform the string "com".
+    String com = Joiner.on("").join(new String[] { "c", "o", "m" });
+    return Joiner.on(".").join(new String[] { com, "newrelic", "api", "agent", "NewRelic" });
+  }
+
+  static void annotateTransaction(String featureKey, String value) {
     if (addCustomParameter != null) {
       try {
         addCustomParameter.invoke(null, featureKey, value);
@@ -32,6 +41,5 @@ static void annotateTransaction(String featureKey, String value) {
         logger.debug(e.toString(), e);
       }
     }
-   }
-
+  }
 }