[CAMEL-19014] SimpleLanguage cache issue

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.19.0, 3.20.1, 3.20.2, 4.0-M1
• Fix Version/s: 3.21.0, 4.0-M3, 4.0.0
• Component/s: camel-core
• Estimated Complexity: Unknown
• Assignee: Rhuan Rocha
• Reporter: Andrea Evangelista
• Created: 06/Feb/23 16:26
• Updated: 31/Aug/23 15:56
• Resolved: 22/Mar/23 11:03

Description

Hi guys, I'm attaching a test class that will reproduce the issue that I'm experiencing.
As summary: The cache inside the SimpleLanguage class looks like it's going to be affected by the evaluation of the simple expression, producing unexpected results.
When the method resolveTemplate is used the result is not the expected one.
To make it work I have to simulate a new entry in the cache making use of the method resolveTemplateNoCache.
Thanks in advance

public class SimpleLanguageTest extends CamelTestSupport {
    @EndpointInject("mock:result")
    private MockEndpoint mockResult;

    @EndpointInject("mock:fail")
    private MockEndpoint mockWithFailure;

    @Test
    public void whenSimpleLanguageNotUseCachedEntriesItWillNotFail() throws Exception {

        mockResult.await(20, TimeUnit.SECONDS);
        mockResult.expectedMessageCount(102);
        assertMockEndpointsSatisfied();
        List<Exchange> exchanges = mockResult.getExchanges();
        exchanges.stream()
                .forEach(exchange -> assertTrue(exchange.getMessage().getHeader("#CustomHeader", String.class).equals("This is a test a with startLabel: `Document` endLabel: `Document` and label: `ALabel`")));


    }

    @Test
    public void whenSimpleLanguageUseCachedEntriesItWillFail() throws Exception {
        mockWithFailure.expectedMessageCount(102);
        assertMockEndpointsSatisfied();
        List<Exchange> exchanges = mockWithFailure.getExchanges();
        exchanges.stream()
                .forEach(exchange -> assertTrue(exchange.getMessage().getHeader("#CustomHeader", String.class).equals("This is a test a with startLabel: `Document` endLabel: `Document` and label: `ALabel`")));


    }

    @Override
    protected RoutesBuilder createRouteBuilder() throws Exception {

        return new RouteBuilder() {
            Map body = new HashMap() {{
                put("label", "ALabel");
                put("startLabel", "Document");
                put("endLabel", "Document");
            }};


            String simpleTemplate = "This is a test a with startLabel: `${body.get('startLabel')}` endLabel: `${body.get('endLabel')}` and label: `${body.get('label')}`";


            @Override
            public void configure() throws Exception {
                from("timer://test-timer?fixedRate=true&period=10&delay=1")
                        .process(new Processor() {
                            @Override
                            public void process(Exchange exchange) throws Exception {
                                exchange.getMessage().setBody(body);
                                exchange.getMessage().setHeader("#CustomHeader", resolveTemplateNoCache(simpleTemplate, exchange));
                            }
                        })
                        .to("mock:result");

                from("timer://test-timer1?fixedRate=true&period=10&delay=1")

                        .process(new Processor() {
                            @Override
                            public void process(Exchange exchange) throws Exception {
                                exchange.getMessage().setBody(body);
                                exchange.getMessage().setHeader("#CustomHeader", resolveTemplateNoCache(simpleTemplate, exchange));
                            }
                        })
                        .to("mock:result");

                from("timer://test-timer2?fixedRate=true&period=10&delay=1")
                        .process(new Processor() {
                            @Override
                            public void process(Exchange exchange) throws Exception {
                                exchange.getMessage().setBody(body);
                                exchange.getMessage().setHeader("#CustomHeader", resolveTemplateNoCache(simpleTemplate, exchange));
                            }
                        })
                        .to("mock:result");

                from("timer://test-timer3?fixedRate=true&period=10&delay=1")
                        .process(new Processor() {
                            @Override
                            public void process(Exchange exchange) throws Exception {
                                exchange.getMessage().setBody(body);
                                exchange.getMessage().setHeader("#CustomHeader", resolveTemplate(simpleTemplate, exchange));
                            }
                        })
                        .to("mock:fail");

                from("timer://test-timer4?fixedRate=true&period=10&delay=1")

                        .process(new Processor() {
                            @Override
                            public void process(Exchange exchange) throws Exception {
                                exchange.getMessage().setBody(body);
                                exchange.getMessage().setHeader("#CustomHeader", resolveTemplate(simpleTemplate, exchange));
                            }
                        })
                        .to("mock:fail");

                from("timer://test-timer5?fixedRate=true&period=10&delay=1")
                        .process(new Processor() {
                            @Override
                            public void process(Exchange exchange) throws Exception {
                                exchange.getMessage().setBody(body);
                                exchange.getMessage().setHeader("#CustomHeader", resolveTemplate(simpleTemplate, exchange));
                            }
                        })
                        .to("mock:fail");
            }

        };
    }

    public String resolveTemplate(String template, Exchange exchange) {
        var simpleExpression = new SimpleExpression();
        simpleExpression.setExpression(template);
        return simpleExpression.evaluate(exchange, String.class);

    }

    public String resolveTemplateNoCache(String template, Exchange exchange) {
        var simpleExpression = new SimpleExpression();
        //This will force to create a new entry in the cache in the SimpleLanguage class
        String nocache = String.join("-", "-nocache", UUID.randomUUID().toString());
        simpleExpression.setExpression("%s%s".formatted(template, nocache));
        return simpleExpression.evaluate(exchange, String.class).replace(nocache, "");

    }
}
 

Issue Links

• fixes: CAMEL-19346 Builder.simple expression is not thread safe
• links to: GitHub Pull Request #9332
• links to: GitHub Pull Request #9333
• links to: GitHub Pull Request #9531