fix issue #308

src/main/user-impl/java/com/mysql/cj/jdbc/ha/ConnectionProxy.java

@@ -307,6 +307,28 @@ class JdbcInterfaceProxy implements InvocationHandler {
       this.invokeOn = toInvokeOn;
     }
 
+    /**
+     * Special handling of method calls that can be handled without making an explicit invocation against the connection
+     * underlying this proxy. See {@link #isDirectExecute(String)}
+     *
+     * @param methodName The name of the method being called
+     * @param args The argument parameters of the method that is being called
+     * @return The results of the special method handling, according to which method was called
+     */
+    private Object executeMethodDirectly(String methodName, Object[] args) {
+      if (METHOD_EQUALS.equals(methodName) && args != null && args.length > 0 && args[0] != null) {
+        return args[0].equals(this);
+      }
+
+      if (METHOD_HASH_CODE.equals(methodName)) {
+        return this.hashCode();
+      }
+
+      // should never reach this statement, as the conditions in this method were previously checked in the method
+      // calling this class using the isForwardingRequired method
+      return null;
+    }
+
     public synchronized Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
       final String methodName = method.getName();
       if (isDirectExecute(methodName)) {

src/test/java/testsuite/integration/container/AuroraMysqlIntegrationTest.java

@@ -46,6 +46,7 @@
 import java.net.UnknownHostException;
 import java.sql.Connection;
 import java.sql.DriverManager;
+import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.Arrays;
 import java.util.HashSet;
@@ -591,4 +592,19 @@ public void test_ConnectionStringWithValuelessParameter() throws SQLException {
     assertTrue(conn.isValid(5));
     conn.close();
   }
+
+  @Test
+  public void test_PreparedStatementHashCodes() throws SQLException, IOException {
+    final Connection conn = connectToInstance(MYSQL_INSTANCE_1_URL + PROXIED_DOMAIN_NAME_SUFFIX, MYSQL_PROXY_PORT);
+    assertTrue(conn.isValid(5));
+
+    PreparedStatement prepStmt1 = conn.prepareCall("select 1");
+    PreparedStatement prepStmt2 = conn.prepareCall("select 1");
+
+    assertNotEquals(prepStmt1.hashCode(), prepStmt2.hashCode());
+    assertNotEquals(prepStmt1, prepStmt2);
+
+    conn.close();
+  }
+
 }