Implement StagemonitorRuntimeAgentAttacherDriver to attach the agent …

…ealier in the lifecycle of JBoss/wildfly

stagemonitor-core/src/main/java/org/stagemonitor/core/instrument/StagemonitorRuntimeAgentAttacherDriver.java

@@ -0,0 +1,71 @@
+package org.stagemonitor.core.instrument;
+
+import java.sql.Connection;
+import java.sql.Driver;
+import java.sql.DriverPropertyInfo;
+import java.sql.SQLException;
+import java.sql.SQLFeatureNotSupportedException;
+import java.util.Properties;
+import java.util.logging.Logger;
+
+import org.slf4j.LoggerFactory;
+import org.stagemonitor.core.CorePlugin;
+import org.stagemonitor.core.Stagemonitor;
+
+/**
+ * This is not a real Driver, it is just used to attach the stagemonitor agent as early in the lifecycle as possible.
+ * Because the earlier the agent is attached, the less classes have to be retransformed, which is a expensive operation.
+ *
+ * Some application server as wildfly load all Driver implementations with a ServiceLoader at startup and even
+ * before @WebListener classes are loaded.
+ */
+public class StagemonitorRuntimeAgentAttacherDriver implements Driver {
+
+	private static final org.slf4j.Logger logger = LoggerFactory.getLogger(StagemonitorRuntimeAgentAttacherDriver.class);
+
+	static  {
+		try {
+			final CorePlugin configuration = Stagemonitor.getConfiguration(CorePlugin.class);
+			if (configuration.isStagemonitorActive() && configuration.isAttachAgentAtRuntime()) {
+				MainStagemonitorClassFileTransformer.performRuntimeAttachment();
+			}
+		} catch (Exception e) {
+			logger.warn(e.getMessage(), e);
+		}
+	}
+
+	@Override
+	public Connection connect(String url, Properties info) throws SQLException {
+		return null;
+	}
+
+	@Override
+	public boolean acceptsURL(String url) throws SQLException {
+		return false;
+	}
+
+	@Override
+	public DriverPropertyInfo[] getPropertyInfo(String url, Properties info) throws SQLException {
+		return new DriverPropertyInfo[0];
+	}
+
+	@Override
+	public int getMajorVersion() {
+		return 0;
+	}
+
+	@Override
+	public int getMinorVersion() {
+		return 0;
+	}
+
+	@Override
+	public boolean jdbcCompliant() {
+		return false;
+	}
+
+	@Override
+	public Logger getParentLogger() throws SQLFeatureNotSupportedException {
+		throw new SQLFeatureNotSupportedException();
+	}
+}

stagemonitor-core/src/main/resources/META-INF/services/java.sql.Driver

@@ -0,0 +1 @@
+org.stagemonitor.core.instrument.StagemonitorRuntimeAgentAttacherDriver

stagemonitor-web/src/main/java/org/stagemonitor/web/attach/RuntimeAgentAttacherListener.java

@@ -16,9 +16,9 @@
 @WebListener
 public class RuntimeAgentAttacherListener implements ServletContextListener {
 
-	private final Logger logger = LoggerFactory.getLogger(getClass());
+	private static final Logger logger = LoggerFactory.getLogger(RuntimeAgentAttacherListener.class);
 
-	public RuntimeAgentAttacherListener() {
+	static  {
 		try {
 			final CorePlugin configuration = Stagemonitor.getConfiguration(CorePlugin.class);
 			if (configuration.isStagemonitorActive() && configuration.isAttachAgentAtRuntime()) {