CAMEL-26332: camel-core - doCatch is skipped after a route called from the doTry continued a failure

core/camel-core-processor/src/main/java/org/apache/camel/processor/errorhandler/RedeliveryErrorHandler.java

@@ -77,6 +77,14 @@ public abstract class RedeliveryErrorHandler extends ErrorHandlerSupport
 
     private static final Logger LOG = LoggerFactory.getLogger(RedeliveryErrorHandler.class);
 
+    // the exception of a failure that was continued (onException continued), which is not a previous exception of a
+    // later failure. A key of its own: Exchange.EXCEPTION_HANDLED is the doCatch's marker that a previous doCatch of
+    // the doTry handled the exception, and a direct call shares the exchange with the caller's doTry.
+    // Internal on purpose: a plain property, not an ExchangePropertyKey or a constant on Exchange, so it is not public
+    // API. As any plain property, it shows in Exchange.getProperties() and in tracer or debugger listings, and
+    // removeProperties("*") removes it.
+    private static final String CONTINUED_EXCEPTION = "CamelErrorHandlerContinuedException";
+
     // factory
     protected PooledExchangeTaskFactory taskFactory;
 
@@ -838,7 +846,7 @@ private void prepareExchangeForContinue(Exchange exchange, boolean isDeadLetterC
             exchange.removeProperty(ExchangePropertyKey.UNIT_OF_WORK_EXHAUSTED);
             // continue but keep the caused exception stored as a property
             // (by default we do not log the failure as we continue routing)
-            exchange.setProperty(ExchangePropertyKey.EXCEPTION_HANDLED, e);
+            exchange.setProperty(CONTINUED_EXCEPTION, e);
             exchange.getExchangeExtension().setErrorHandlerHandled(true);
 
             LOG.trace("This exchange is continued: {}", exchange);
@@ -872,7 +880,7 @@ protected void handleException() {
             // e is never null
 
             Throwable previous = exchange.getProperty(ExchangePropertyKey.EXCEPTION_CAUGHT, Throwable.class);
-            if (previous != null && previous == exchange.getProperty(ExchangePropertyKey.EXCEPTION_HANDLED)) {
+            if (previous != null && previous == exchange.getProperty(CONTINUED_EXCEPTION)) {
                 // the previous exception was handled (continued) so this is a new failure
                 previous = null;
             }
@@ -1395,7 +1403,7 @@ protected void prepareExchangeForContinue(Exchange exchange, boolean isDeadLette
             // and mark it as handled (continued), so it is not regarded as a previous exception of a later failure
             Exception handled = exchange.getProperty(ExchangePropertyKey.EXCEPTION_CAUGHT, Exception.class);
             if (handled != null) {
-                exchange.setProperty(ExchangePropertyKey.EXCEPTION_HANDLED, handled);
+                exchange.setProperty(CONTINUED_EXCEPTION, handled);
             }
 
             // create log message
@@ -1448,7 +1456,7 @@ protected void handleException() {
             // e is never null
 
             Throwable previous = exchange.getProperty(ExchangePropertyKey.EXCEPTION_CAUGHT, Throwable.class);
-            if (previous != null && previous == exchange.getProperty(ExchangePropertyKey.EXCEPTION_HANDLED)) {
+            if (previous != null && previous == exchange.getProperty(CONTINUED_EXCEPTION)) {
                 // the previous exception was handled (continued) so this is a new failure
                 previous = null;
             }

core/camel-core/src/test/java/org/apache/camel/processor/onexception/DoCatchAfterContinuedFailureInCalledRouteTest.java

@@ -0,0 +1,218 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.processor.onexception;
+
+import java.time.Duration;
+
+import org.apache.camel.ContextTestSupport;
+import org.apache.camel.Exchange;
+import org.apache.camel.builder.RouteBuilder;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTimeoutPreemptively;
+
+/**
+ * A route called from a doTry body continues a failure ({@code onException(...).continued(true)}). A later exception in
+ * the same doTry body must still be caught by the doCatch.
+ */
+class DoCatchAfterContinuedFailureInCalledRouteTest extends ContextTestSupport {
+
+    @Override
+    public boolean isUseRouteBuilder() {
+        return false;
+    }
+
+    private Exchange send(String call, boolean redelivery) throws Exception {
+        context.addRoutes(new RouteBuilder() {
+            @Override
+            public void configure() {
+                if (redelivery) {
+                    onException(NumberFormatException.class).maximumRedeliveries(1).redeliveryDelay(0).continued(true);
+                } else {
+                    onException(NumberFormatException.class).continued(true);
+                }
+
+                var body = from("direct:start").doTry();
+                switch (call) {
+                    case "to" -> body.to("direct:callee");
+                    case "routingSlip" -> body.routingSlip(constant("direct:callee"));
+                    case "recipientList" -> body.recipientList(constant("direct:callee"));
+                    case "dynamicRouter" -> body.dynamicRouter(method(DoCatchAfterContinuedFailureInCalledRouteTest.class,
+                            "callCalleeOnce"));
+                    case "calleeOk" -> body.to("direct:calleeOk");
+                    default -> {
+                        // nothing before the exception
+                    }
+                }
+                body.to("mock:next")
+                        .throwException(new IllegalStateException("after the call"))
+                        .doCatch(IllegalArgumentException.class)
+                        .to("mock:otherCatch")
+                        .doCatch(IllegalStateException.class)
+                        .to("mock:catch")
+                        .doCatch(Exception.class)
+                        .to("mock:lastCatch")
+                        .end()
+                        .to("mock:result");
+
+                from("direct:callee").throwException(new NumberFormatException("in callee")).to("mock:calleeEnd");
+                from("direct:calleeOk").to("mock:calleeEnd");
+            }
+        });
+        context.start();
+
+        return sendBounded();
+    }
+
+    private Exchange sendBounded() {
+        return assertTimeoutPreemptively(Duration.ofSeconds(10),
+                () -> template.send("direct:start", e -> e.getMessage().setBody("Hello")), "the send did not complete");
+    }
+
+    public static String callCalleeOnce(Exchange exchange) {
+        return exchange.getProperty(Exchange.SLIP_ENDPOINT) == null ? "direct:callee" : null;
+    }
+
+    private void assertCaughtOnce(Exchange out) {
+        assertNull(out.getException(), "the doCatch handles the exception");
+        assertEquals(1, getMockEndpoint("mock:next").getReceivedCounter(), "mock:next");
+        assertEquals(1, getMockEndpoint("mock:catch").getReceivedCounter(), "mock:catch");
+        // only the first matching doCatch runs
+        assertEquals(0, getMockEndpoint("mock:otherCatch").getReceivedCounter(), "mock:otherCatch");
+        assertEquals(0, getMockEndpoint("mock:lastCatch").getReceivedCounter(), "mock:lastCatch");
+        assertEquals(1, getMockEndpoint("mock:result").getReceivedCounter(), "mock:result");
+        // the doCatch sees the exception it caught, not the continued one
+        Exchange caught = getMockEndpoint("mock:catch").getReceivedExchanges().get(0);
+        Exception e = caught.getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class);
+        assertInstanceOf(IllegalStateException.class, e);
+        assertEquals("after the call", e.getMessage());
+        assertEquals(0, e.getSuppressed().length, "the continued exception is not a previous exception");
+    }
+
+    @Test
+    void continuedInCalledRoute() throws Exception {
+        Exchange out = send("to", false);
+        // the called route continued after its failure
+        assertEquals(1, getMockEndpoint("mock:calleeEnd").getReceivedCounter(), "mock:calleeEnd");
+        // the doCatch (and the debugger, CatchDefinition.acceptDebugger) reads this property as "a previous doCatch
+        // of the doTry handled the exception"
+        Exchange next = getMockEndpoint("mock:next").getReceivedExchanges().get(0);
+        assertNull(next.getProperty(Exchange.EXCEPTION_HANDLED), "a continued failure is not a handled doCatch");
+        assertCaughtOnce(out);
+    }
+
+    @Test
+    void continuedInRoutingSlip() throws Exception {
+        assertCaughtOnce(send("routingSlip", false));
+    }
+
+    @Test
+    void continuedInRecipientList() throws Exception {
+        assertCaughtOnce(send("recipientList", false));
+    }
+
+    @Test
+    void continuedInDynamicRouter() throws Exception {
+        assertCaughtOnce(send("dynamicRouter", false));
+    }
+
+    @Test
+    void continuedAfterRedeliveryInCalledRoute() throws Exception {
+        assertCaughtOnce(send("to", true));
+    }
+
+    @Test
+    void controlNothingBeforeTheException() throws Exception {
+        assertCaughtOnce(send("none", false));
+    }
+
+    @Test
+    void controlCalledRouteDoesNotFail() throws Exception {
+        Exchange out = send("calleeOk", false);
+        assertEquals(1, getMockEndpoint("mock:calleeEnd").getReceivedCounter(), "mock:calleeEnd");
+        assertCaughtOnce(out);
+    }
+
+    @Test
+    void continuedBeforeTheDoTryIsNotAPreviousException() throws Exception {
+        context.addRoutes(new RouteBuilder() {
+            @Override
+            public void configure() {
+                onException(NumberFormatException.class).continued(true);
+
+                from("direct:start")
+                        .to("direct:callee")
+                        .doTry()
+                        .to("direct:fail")
+                        .doCatch(IllegalStateException.class)
+                        .to("mock:catch")
+                        .end();
+
+                from("direct:callee").throwException(new NumberFormatException("in callee"));
+                from("direct:fail").throwException(new IllegalStateException("in fail"));
+            }
+        });
+        context.start();
+
+        Exchange out = sendBounded();
+        assertNull(out.getException(), "the doCatch handles the exception");
+        assertEquals(1, getMockEndpoint("mock:catch").getReceivedCounter(), "mock:catch");
+        Exception e = getMockEndpoint("mock:catch").getReceivedExchanges().get(0)
+                .getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class);
+        assertEquals("in fail", e.getMessage());
+        // as without the doTry (ErrorHandlerFailurePathsTest.testContinuedThenUnrelatedFailure)
+        assertEquals(0, e.getSuppressed().length, "the continued exception is not a previous exception");
+    }
+
+    @Test
+    void controlExceptionThrownInDoCatchIsNotCaughtByTheNextDoCatch() throws Exception {
+        context.addRoutes(new RouteBuilder() {
+            @Override
+            public void configure() {
+                onException(NumberFormatException.class).continued(true);
+
+                from("direct:start")
+                        .doTry()
+                        .throwException(new IllegalArgumentException("in try"))
+                        .doCatch(IllegalArgumentException.class)
+                        .to("mock:catch")
+                        // continues a failure, then this doCatch fails
+                        .to("direct:callee")
+                        .throwException(new IllegalStateException("in catch"))
+                        .doCatch(IllegalStateException.class)
+                        .to("mock:otherCatch")
+                        .end()
+                        .to("mock:result");
+
+                from("direct:callee").throwException(new NumberFormatException("in callee")).to("mock:calleeEnd");
+            }
+        });
+        context.start();
+
+        Exchange out = sendBounded();
+        assertEquals(1, getMockEndpoint("mock:catch").getReceivedCounter(), "mock:catch");
+        assertEquals(1, getMockEndpoint("mock:calleeEnd").getReceivedCounter(), "mock:calleeEnd");
+        // as in Java, an exception thrown by a doCatch is not caught by another doCatch of the same doTry
+        assertEquals(0, getMockEndpoint("mock:otherCatch").getReceivedCounter(), "mock:otherCatch");
+        assertEquals(0, getMockEndpoint("mock:result").getReceivedCounter(), "mock:result");
+        assertInstanceOf(IllegalStateException.class, out.getException());
+        assertEquals("in catch", out.getException().getMessage());
+    }
+}