Added support for the 'executor' element within the 'task' namespace for creating a ThreadPoolTaskExecutor instance.

org.springframework.context/src/main/java/org/springframework/scheduling/config/ExecutorBeanDefinitionParser.java

@@ -0,0 +1,146 @@
+/*
+ * Copyright 2002-2009 the original author or authors.
+ *
+ * Licensed 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.springframework.scheduling.config;
+
+import java.util.concurrent.ThreadPoolExecutor;
+
+import org.w3c.dom.Element;
+
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;
+import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.core.JdkVersion;
+import org.springframework.util.StringUtils;
+
+/**
+ * Parser for the 'executor' element of the 'task' namespace.
+ * 
+ * @author Mark Fisher
+ * @since 3.0
+ */
+public class ExecutorBeanDefinitionParser extends AbstractSingleBeanDefinitionParser {
+
+	@Override
+	protected String getBeanClassName(Element element) {
+		if (this.shouldUseBackport(element)) {
+			return "org.springframework.scheduling.backportconcurrent.ThreadPoolTaskExecutor";
+		}
+		return "org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor";
+	}
+
+	@Override
+	protected void doParse(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
+		String keepAliveSeconds = element.getAttribute("keep-alive");
+		if (StringUtils.hasText(keepAliveSeconds)) {
+			builder.addPropertyValue("keepAliveSeconds", keepAliveSeconds);
+		}
+		String queueCapacity = element.getAttribute("queue-capacity");
+		if (StringUtils.hasText(queueCapacity)) {
+			builder.addPropertyValue("queueCapacity", queueCapacity);
+		}
+		this.configureRejectionPolicy(element, builder);
+		String size = element.getAttribute("size");
+		if (!StringUtils.hasText(size)) {
+			return;
+		}
+		Integer[] range = null;
+		try {
+			int separatorIndex = size.indexOf('-');
+			if (separatorIndex != -1) {
+				range = new Integer[2];
+				range[0] = Integer.valueOf(size.substring(0, separatorIndex));
+				range[1] = Integer.valueOf(size.substring(separatorIndex + 1, size.length()));
+				if (range[0] > range[1]) {
+					parserContext.getReaderContext().error(
+							"Lower bound of size range must not exceed the upper bound.", element);
+				}
+				if (!StringUtils.hasText(queueCapacity)) {
+					// no queue-capacity provided, so unbounded
+					if (range[0] == 0) {
+						// actually set 'corePoolSize' to the upper bound of the range
+						// but allow core threads to timeout
+						builder.addPropertyValue("allowCoreThreadTimeOut", true);
+						range[0] = range[1];
+					}
+					else {
+						// non-zero lower bound implies a core-max size range
+						parserContext.getReaderContext().error(
+								"A non-zero lower bound for the size range requires a queue-capacity value.", element);
+					}
+				}
+			}
+			else {
+				Integer value = Integer.valueOf(size);
+				range = new Integer[] {value, value};
+			}
+		}
+		catch (NumberFormatException ex) {
+			parserContext.getReaderContext().error("Invalid size value [" + size + "]: only " +
+					"single maximum integer (e.g. \"5\") and minimum-maximum combo (e.g. \"3-5\") supported.",
+					element, ex);
+		}
+		if (range != null) {
+			builder.addPropertyValue("corePoolSize", range[0]);
+			builder.addPropertyValue("maxPoolSize", range[1]);
+		}
+	}
+
+	private void configureRejectionPolicy(Element element, BeanDefinitionBuilder builder) {
+		String rejectionPolicy = element.getAttribute("rejection-policy");
+		if (!StringUtils.hasText(rejectionPolicy)) {
+			return;
+		}
+		Object handler = null;		
+		boolean createBackportHandler = this.shouldUseBackport(element);
+		if (rejectionPolicy.equals("ABORT")) {
+			if (createBackportHandler) {
+				handler = new edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor.AbortPolicy();
+			}
+			else {
+				handler = new ThreadPoolExecutor.AbortPolicy();
+			}
+		}
+		if (rejectionPolicy.equals("CALLER_RUNS")) {
+			if (createBackportHandler) {
+				handler = new edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy();
+			}
+			else {
+				handler = new ThreadPoolExecutor.CallerRunsPolicy();
+			}
+		}
+		if (rejectionPolicy.equals("DISCARD")) {
+			if (createBackportHandler) {
+				handler = new edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor.DiscardPolicy();
+			}
+			handler = new ThreadPoolExecutor.DiscardPolicy();
+		}
+		if (rejectionPolicy.equals("DISCARD_OLDEST")) {
+			if (createBackportHandler) {
+				handler = new edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy();
+			}
+			handler = new ThreadPoolExecutor.DiscardOldestPolicy();
+		}
+		builder.addPropertyValue("rejectedExecutionHandler", handler);
+	}
+
+	private boolean shouldUseBackport(Element element) {
+		String size = element.getAttribute("size");
+		return StringUtils.hasText(size) && size.startsWith("0")
+				&& JdkVersion.getMajorJavaVersion() < JdkVersion.JAVA_16;
+	}
+
+}

org.springframework.context/src/main/java/org/springframework/scheduling/config/TaskNamespaceHandler.java

@@ -28,6 +28,7 @@ public class TaskNamespaceHandler extends NamespaceHandlerSupport {
 
 	public void init() {
 		this.registerBeanDefinitionParser("annotation-driven", new AnnotationDrivenBeanDefinitionParser());
+		this.registerBeanDefinitionParser("executor", new ExecutorBeanDefinitionParser());
 		this.registerBeanDefinitionParser("scheduled-tasks", new ScheduledTasksBeanDefinitionParser());
 		this.registerBeanDefinitionParser("scheduler", new SchedulerBeanDefinitionParser());
 	}