camel-core - Using shared dummy exchange instance for special needs i… (

#14616) * camel-core - Using shared dummy exchange instance for special needs instead of creating a new instance to be thrown away afterwards.
apache · Jun 22, 2024 · 1a6a166 · 1a6a166
1 parent 7a316a0
commit 1a6a166
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Showing 9 changed files with 45 additions and 27 deletions.
diff --git a/...el-controlbus/src/main/java/org/apache/camel/component/controlbus/ControlBusProducer.java b/...el-controlbus/src/main/java/org/apache/camel/component/controlbus/ControlBusProducer.java
@@ -116,13 +116,12 @@ public void run() {
             Object result = null;
 
             try {
-                // create dummy exchange
-                Exchange dummy = ExchangeHelper.createCopy(exchange, true);
-
-                task = dummy.getIn().getMandatoryBody(String.class);
+                // create copy of exchange to not cause side effect
+                Exchange copy = ExchangeHelper.createCopy(exchange, true);
+                task = copy.getIn().getMandatoryBody(String.class);
                 if (task != null) {
                     Expression exp = language.createExpression(task);
-                    result = exp.evaluate(dummy, Object.class);
+                    result = exp.evaluate(copy, Object.class);
                 }
 
                 if (result != null && !getEndpoint().isAsync()) {

diff --git a/components/camel-ftp/src/main/java/org/apache/camel/component/file/remote/FtpConsumer.java b/components/camel-ftp/src/main/java/org/apache/camel/component/file/remote/FtpConsumer.java
@@ -28,6 +28,7 @@
 import org.apache.camel.component.file.GenericFile;
 import org.apache.camel.component.file.GenericFileOperationFailedException;
 import org.apache.camel.component.file.GenericFileProcessStrategy;
+import org.apache.camel.support.ExchangeHelper;
 import org.apache.camel.util.FileUtil;
 import org.apache.camel.util.ObjectHelper;
 import org.apache.camel.util.StringHelper;
@@ -217,7 +218,7 @@ private FTPFile[] pollNamedFile() {
         FTPFile[] files = null;
         // we cannot use the LIST command(s) so we can only poll a named
         // file so created a pseudo file with that name
-        Exchange dummy = endpoint.createExchange();
+        Exchange dummy = ExchangeHelper.getDummy(getEndpoint().getCamelContext());
         String name = evaluateFileExpression(dummy);
         if (name != null) {
             FTPFile file = new FTPFile();

diff --git a/components/camel-ftp/src/main/java/org/apache/camel/component/file/remote/SftpConsumer.java b/components/camel-ftp/src/main/java/org/apache/camel/component/file/remote/SftpConsumer.java
@@ -28,6 +28,7 @@
 import org.apache.camel.component.file.GenericFile;
 import org.apache.camel.component.file.GenericFileOperationFailedException;
 import org.apache.camel.component.file.GenericFileProcessStrategy;
+import org.apache.camel.support.ExchangeHelper;
 import org.apache.camel.util.FileUtil;
 import org.apache.camel.util.ObjectHelper;
 import org.apache.camel.util.StringHelper;
@@ -216,7 +217,7 @@ private SftpRemoteFile[] pollNamedFile() {
 
         // we cannot use the LIST command(s) so we can only poll a named
         // file so created a pseudo file with that name
-        Exchange dummy = endpoint.createExchange();
+        Exchange dummy = ExchangeHelper.getDummy(getEndpoint().getCamelContext());
         String name = evaluateFileExpression(dummy);
         if (name != null) {
             SftpRemoteFile file = new SftpRemoteFileSingle(name);

diff --git a/components/camel-sql/src/main/java/org/apache/camel/component/sql/SqlConsumer.java b/components/camel-sql/src/main/java/org/apache/camel/component/sql/SqlConsumer.java
@@ -30,6 +30,7 @@
 import org.apache.camel.Processor;
 import org.apache.camel.RollbackExchangeException;
 import org.apache.camel.RuntimeCamelException;
+import org.apache.camel.spi.ExchangeFactory;
 import org.apache.camel.support.ResourceHelper;
 import org.apache.camel.support.ScheduledBatchPollingConsumer;
 import org.apache.camel.util.CastUtils;
@@ -50,6 +51,7 @@ public class SqlConsumer extends ScheduledBatchPollingConsumer {
 
     private final String query;
     private String resolvedQuery;
+    private final ExchangeFactory exchangeFactory;
     private final JdbcTemplate jdbcTemplate;
     private final NamedParameterJdbcTemplate namedJdbcTemplate;
     private final SqlParameterSource parameterSource;
@@ -84,6 +86,7 @@ public SqlConsumer(DefaultSqlEndpoint endpoint, Processor processor, JdbcTemplat
         this.parameterSource = null;
         this.sqlPrepareStatementStrategy = sqlPrepareStatementStrategy;
         this.sqlProcessingStrategy = sqlProcessingStrategy;
+        this.exchangeFactory = endpoint.getCamelContext().getCamelContextExtension().getExchangeFactory();
     }
 
     public SqlConsumer(DefaultSqlEndpoint endpoint, Processor processor, NamedParameterJdbcTemplate namedJdbcTemplate,
@@ -96,6 +99,7 @@ public SqlConsumer(DefaultSqlEndpoint endpoint, Processor processor, NamedParame
         this.parameterSource = parameterSource;
         this.sqlPrepareStatementStrategy = sqlPrepareStatementStrategy;
         this.sqlProcessingStrategy = sqlProcessingStrategy;
+        this.exchangeFactory = endpoint.getCamelContext().getCamelContextExtension().getExchangeFactory();
     }
 
     @Override
@@ -129,7 +133,7 @@ protected int poll() throws Exception {
         shutdownRunningTask = null;
         pendingExchanges = 0;
 
-        final Exchange dummy = getEndpoint().createExchange();
+        final Exchange dummy = exchangeFactory.create(getEndpoint(), true);
         final String preparedQuery
                 = sqlPrepareStatementStrategy.prepareQuery(resolvedQuery, getEndpoint().isAllowNamedParameters(), dummy);
 

diff --git a/core/camel-core-model/src/main/java/org/apache/camel/model/BeanModelHelper.java b/core/camel-core-model/src/main/java/org/apache/camel/model/BeanModelHelper.java
@@ -27,9 +27,9 @@
 import org.apache.camel.NoSuchBeanException;
 import org.apache.camel.RouteTemplateContext;
 import org.apache.camel.RuntimeCamelException;
-import org.apache.camel.spi.ExchangeFactory;
 import org.apache.camel.spi.Language;
 import org.apache.camel.spi.ScriptingLanguage;
+import org.apache.camel.support.ExchangeHelper;
 import org.apache.camel.support.PropertyBindingSupport;
 import org.apache.camel.support.ScriptHelper;
 import org.apache.camel.util.StringHelper;
@@ -78,16 +78,10 @@ public static Object newInstance(BeanFactoryDefinition def, CamelContext context
                 bindings.put("context", context);
                 target = slan.evaluate(def.getScript(), bindings, clazz);
             } else {
-                // exchange based languages needs a dummy exchange to be evaluated
-                ExchangeFactory ef = context.getCamelContextExtension().getExchangeFactory();
-                Exchange dummy = ef.create(false);
-                try {
-                    String text = ScriptHelper.resolveOptionalExternalScript(context, dummy, def.getScript());
-                    Expression exp = lan.createExpression(text);
-                    target = exp.evaluate(dummy, clazz);
-                } finally {
-                    ef.release(dummy);
-                }
+                Exchange dummy = ExchangeHelper.getDummy(context);
+                String text = ScriptHelper.resolveOptionalExternalScript(context, dummy, def.getScript());
+                Expression exp = lan.createExpression(text);
+                target = exp.evaluate(dummy, clazz);
             }
 
             // a bean must be created
@@ -215,9 +209,8 @@ public static void bind(BeanFactoryDefinition<?> def, RouteTemplateContext route
                 // and memorize so the script is only evaluated once and the local bean is the same
                 // if a route template refers to the local bean multiple times
                 routeTemplateContext.bind(def.getName(), clazz, Suppliers.memorize(() -> {
-                    ExchangeFactory ef = camelContext.getCamelContextExtension().getExchangeFactory();
-                    Exchange dummy = ef.create(false);
                     try {
+                        Exchange dummy = ExchangeHelper.getDummy(camelContext);
                         String text = ScriptHelper.resolveOptionalExternalScript(camelContext, dummy, script);
                         if (text != null) {
                             Expression exp = lan.createExpression(text);
@@ -242,8 +235,6 @@ public static void bind(BeanFactoryDefinition<?> def, RouteTemplateContext route
                     } catch (Exception e) {
                         throw new IllegalStateException(
                                 "Cannot create bean: " + def.getType(), e);
-                    } finally {
-                        ef.release(dummy);
                     }
                 }));
             }

diff --git a/core/camel-core-reifier/src/main/java/org/apache/camel/reifier/ChoiceReifier.java b/core/camel-core-reifier/src/main/java/org/apache/camel/reifier/ChoiceReifier.java
@@ -31,7 +31,7 @@
 import org.apache.camel.processor.ChoiceProcessor;
 import org.apache.camel.processor.FilterProcessor;
 import org.apache.camel.spi.ExpressionFactoryAware;
-import org.apache.camel.support.DefaultExchange;
+import org.apache.camel.support.ExchangeHelper;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -100,7 +100,7 @@ private void initBranch(WhenDefinition whenClause) {
      */
     private Processor getMatchingBranchProcessor() throws Exception {
         // evaluate when predicates to optimize
-        Exchange dummy = new DefaultExchange(camelContext);
+        Exchange dummy = ExchangeHelper.getDummy(camelContext);
         for (WhenDefinition whenClause : definition.getWhenClauses()) {
             ExpressionDefinition exp = whenClause.getExpression();
             exp.initPredicate(camelContext);

diff --git a/core/camel-core/src/test/java/org/apache/camel/util/ExchangeHelperTest.java b/core/camel-core/src/test/java/org/apache/camel/util/ExchangeHelperTest.java
@@ -40,6 +40,15 @@ public class ExchangeHelperTest extends ContextTestSupport {
 
     protected Exchange exchange;
 
+    @Test
+    public void testGetDummy() {
+        Exchange one = ExchangeHelper.getDummy(context);
+        Exchange two = ExchangeHelper.getDummy(context);
+        assertSame(one, two);
+        assertNotSame(exchange, one);
+        assertNotSame(exchange, two);
+    }
+
     @Test
     public void testValidProperty() throws Exception {
         String value = ExchangeHelper.getMandatoryProperty(exchange, "foo", String.class);

diff --git a/core/camel-support/src/main/java/org/apache/camel/support/ExchangeHelper.java b/core/camel-support/src/main/java/org/apache/camel/support/ExchangeHelper.java
@@ -68,12 +68,25 @@ public final class ExchangeHelper {
             = ObjectHelper.getSystemProperty(Exchange.DEFAULT_CHARSET_PROPERTY, "UTF-8");
     private static final Charset DEFAULT_CHARSET = Charset.forName(DEFAULT_CHARSET_NAME);
 
+    private static Exchange DUMMY;
+
     /**
      * Utility classes should not have a public constructor.
      */
     private ExchangeHelper() {
     }
 
+    /**
+     * Gets a singleton dummy exchange used for special purposes only.
+     */
+    public static Exchange getDummy(CamelContext context) {
+        // we dont worry about thread-safety
+        if (DUMMY == null) {
+            DUMMY = new DefaultExchange(context);
+        }
+        return DUMMY;
+    }
+
     /**
      * Extracts the Exchange.BINDING of the given type or null if not present
      *

diff --git a/core/camel-support/src/main/java/org/apache/camel/support/component/RawParameterHelper.java b/core/camel-support/src/main/java/org/apache/camel/support/component/RawParameterHelper.java
@@ -20,7 +20,7 @@
 
 import org.apache.camel.CamelContext;
 import org.apache.camel.Exchange;
-import org.apache.camel.support.DefaultExchange;
+import org.apache.camel.support.ExchangeHelper;
 import org.apache.camel.util.URISupport;
 
 public final class RawParameterHelper {
@@ -42,7 +42,7 @@ private RawParameterHelper() {
     public static void resolveRawParameterValues(CamelContext camelContext, Map<String, Object> parameters) {
         URISupport.resolveRawParameterValues(parameters, s -> {
             if (s != null && s.contains("$simple{")) {
-                Exchange dummy = new DefaultExchange(camelContext);
+                Exchange dummy = ExchangeHelper.getDummy(camelContext);
                 s = camelContext.resolveLanguage("simple").createExpression(s).evaluate(dummy, String.class);
             }
             return s;