Auto detect ConnectInfo from underlying DataSource (#94)

Author: quaff

src/main/java/io/opentracing/contrib/jdbc/TracingDataSource.java

@@ -19,7 +19,9 @@
 import io.opentracing.Span;
 import io.opentracing.Tracer;
 import io.opentracing.contrib.common.WrapperProxy;
+import io.opentracing.contrib.jdbc.parser.URLParser;
 import java.io.PrintWriter;
+import java.lang.reflect.Method;
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.SQLFeatureNotSupportedException;
@@ -40,7 +42,7 @@ public class TracingDataSource implements DataSource, AutoCloseable {
 
   public TracingDataSource(final Tracer tracer,
       final DataSource underlying) {
-    this(tracer, underlying, ConnectionInfo.UNKNOWN_CONNECTION_INFO, DEFAULT_WITH_ACTIVE_SPAN_ONLY,
+    this(tracer, underlying, null, DEFAULT_WITH_ACTIVE_SPAN_ONLY,
         DEFAULT_IGNORED_STATEMENTS);
   }
 
@@ -51,7 +53,25 @@ public TracingDataSource(final Tracer tracer,
       final Set<String> ignoreStatements) {
     this.tracer = tracer;
     this.underlying = underlying;
-    this.connectionInfo = connectionInfo;
+    ConnectionInfo info = connectionInfo;
+    if (info == null) {
+      try {
+        Method method;
+        try {
+          method = underlying.getClass().getMethod("getJdbcUrl");
+        } catch (NoSuchMethodException e) {
+          try {
+            method = underlying.getClass().getMethod("getUrl");
+          } catch (NoSuchMethodException nsme) {
+            method = null;
+          }
+        }
+        info = URLParser.parse((String) method.invoke(underlying));
+      } catch (Exception ignored) {
+        info = ConnectionInfo.UNKNOWN_CONNECTION_INFO;
+      }
+    }
+    this.connectionInfo = info;
     this.withActiveSpanOnly = withActiveSpanOnly;
     this.ignoreStatements = ignoreStatements;
   }
@@ -140,4 +160,4 @@ public void close() throws Exception {
       ((AutoCloseable) underlying).close();
     }
   }
-}
+}

src/test/java/io/opentracing/contrib/jdbc/TracingDataSourceTest.java

@@ -13,6 +13,7 @@
  */
 package io.opentracing.contrib.jdbc;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
@@ -62,6 +63,18 @@ public void rethrows_any_error() throws Exception {
     }
   }
 
+  @Test
+  public void detect_connection_info() throws Exception {
+    final BasicDataSource dataSource = getDataSource();
+    final MockTracer mockTracer = new MockTracer();
+    try (final TracingDataSource tracingDataSource = new TracingDataSource(mockTracer, dataSource)) {
+      tracingDataSource.getConnection();
+    }
+    assertFalse(mockTracer.finishedSpans().isEmpty());
+    MockSpan finishedSpan = mockTracer.finishedSpans().get(0);
+    assertEquals("Span contains tag db.type=h2", "h2", finishedSpan.tags().get(Tags.DB_TYPE.getKey()));
+  }
+
   private static BasicDataSource getDataSource() {
     BasicDataSource dataSource = new BasicDataSource();
     dataSource.setUrl("jdbc:h2:mem:dataSourceTest");