runtime/org.argeo.slc.core/src/main/java/org/argeo/slc/core/execution/generator/ExecutionFlowGenerator.java

   1 package org.argeo.slc.core.execution.generator;
   2
   3 import java.util.HashMap;
   4
   5 import org.apache.commons.logging.Log;
   6 import org.apache.commons.logging.LogFactory;
   7 import org.argeo.slc.SlcException;
   8 import org.springframework.aop.scope.ScopedProxyUtils;
   9 import org.springframework.beans.BeansException;
  10 import org.springframework.beans.MutablePropertyValues;
  11 import org.springframework.beans.factory.config.BeanDefinitionHolder;
  12 import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
  13 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
  14 import org.springframework.beans.factory.config.RuntimeBeanReference;
  15 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
  16 import org.springframework.beans.factory.support.GenericBeanDefinition;
  17 import org.springframework.core.Ordered;
  18 import org.springframework.core.PriorityOrdered;
  19
  20 /**
  21  * Generates <code>ExecutionFlows</code> and <code>Runnables</code> as
  22  * beans in the Spring Application Context.
  23  * Called by the Application Context as a <code>BeanFactoryPostProcessor</code>.
  24  * Two kinds of beans are generated:
  25  * <code>RunnableCallFlow</code>, calling a list of <code>Runnables</code> from the
  26  * Application Context after configuring the <code>ExecutionContext</code>,
  27  * and outputs of a <code>RunnableFactory</code>.
  28  */
  29 public class ExecutionFlowGenerator implements BeanFactoryPostProcessor,
  30                 PriorityOrdered {
  31
  32         private final Log log = LogFactory.getLog(getClass());
  33
  34         /**
  35          * Source providing a list of <code>RunnableCallFlowDescriptor</code>
  36          * used to create <code>RunnableCallFlow</code> and a list of
  37          * <code>RunnableDataNode</code> used to create any kind of flow via a factory
  38          */
  39         protected ExecutionFlowGeneratorSource source;
  40
  41         /**
  42          * Factory used to create Runnables in the Application context from
  43          * the <code>RunnableDataNode</code> provided from the source.
  44          */
  45         protected RunnableFactory runnableFactory;
  46
  47         /**
  48          * Bean name of the <code>ExecutionContext</code>.
  49          * Used to provide the created <code>RunnableCallFlow</code> beans
  50          * with a <code>RuntimeBeanReference</code> to
  51          * the <code>ExecutionContext</code>
  52          */
  53         private String executionContextBeanName = "executionContext";
  54
  55         /**
  56          * Bean name of the context values Map.
  57          * A bean of class HashMap is created with this name, and a
  58          * <code>RuntimeBeanReference</code> is provided to the created
  59          * <code>RunnableCallFlow</code> beans.
  60          */
  61         private String contextValuesBeanName = "executionFlowGenerator.contextValues";
  62
  63         /**
  64          * Prefix added to the bean names defined in each
  65          * <code>RunnableCallFlowDescriptor</code>
  66          */
  67         private String flowBeanNamesPrefix = "";
  68
  69         public void postProcessBeanFactory(
  70                         ConfigurableListableBeanFactory beanFactory) throws BeansException {
  71
  72                 // assert that the beanFactory is a BeanDefinitionRegistry
  73                 if (!(beanFactory instanceof BeanDefinitionRegistry)) {
  74                         throw new SlcException("Can only work on "
  75                                         + BeanDefinitionRegistry.class);
  76                 }
  77
  78                 // add bean for the Context Values Map
  79                 createAndRegisterContextValuesBean((BeanDefinitionRegistry) beanFactory);
  80
  81                 // add beans for each RunnableDataNode
  82                 for(RunnableDataNode node : source.getRunnableDataNodes()) {
  83                         runnableFactory.createAndRegisterRunnable(node, (BeanDefinitionRegistry) beanFactory);
  84                 }
  85
  86                 // add beans for each RunnableCallFlowDescriptor of the source to the application context
  87                 for (RunnableCallFlowDescriptor descriptor : source
  88                                 .getRunnableCallFlowDescriptors()) {
  89                         createAndRegisterFlowFor(descriptor, (BeanDefinitionRegistry) beanFactory);
  90                 }
  91         }
  92
  93         /**
  94          * Creates a <code>RunnableCallFlow</code> bean
  95          * for a <code>RunnableCallFlowDescriptor</code> and registers
  96          * it in the <code>BeanDefinitionRegistry</code>
  97          * @param flowDescriptor
  98          * @param registry
  99          */
 100         private void createAndRegisterFlowFor(RunnableCallFlowDescriptor flowDescriptor, BeanDefinitionRegistry registry) {
 101                 // create the flow bean
 102                 GenericBeanDefinition flowBean = new GenericBeanDefinition();
 103                 flowBean.setBeanClass(RunnableCallFlow.class);
 104
 105                 String beanName = flowBeanNamesPrefix + flowDescriptor.getBeanName();
 106
 107                 MutablePropertyValues mpv = new MutablePropertyValues();
 108                 mpv.addPropertyValue("runnableCalls", flowDescriptor.getRunnableCalls());
 109                 mpv.addPropertyValue("sharedContextValuesMap", new RuntimeBeanReference(contextValuesBeanName));
 110
 111                 mpv.addPropertyValue("name", beanName);
 112                 mpv.addPropertyValue("path", flowDescriptor.getPath());
 113
 114                 mpv.addPropertyValue("executionContext", new RuntimeBeanReference(executionContextBeanName));
 115
 116                 flowBean.setPropertyValues(mpv);
 117
 118                 // register it
 119                 if(log.isDebugEnabled()) {
 120                         log.debug("Registering bean definition for RunnableCallFlow " + beanName);
 121                 }
 122                 registry.registerBeanDefinition(beanName, flowBean);
 123         }
 124
 125         /**
 126          * Creates the Context Values bean and register it in the
 127          * <code>BeanDefinitionRegistry</code>
 128          * @param registry
 129          */
 130         private void createAndRegisterContextValuesBean(BeanDefinitionRegistry registry) {
 131                 GenericBeanDefinition contextValuesBean = new GenericBeanDefinition();
 132                 contextValuesBean.setBeanClass(HashMap.class);
 133
 134                 BeanDefinitionHolder bdh = ScopedProxyUtils.createScopedProxy(new BeanDefinitionHolder(contextValuesBean, contextValuesBeanName), registry, true);
 135                 registry.registerBeanDefinition(contextValuesBeanName, bdh.getBeanDefinition());
 136         }
 137
 138         public int getOrder() {
 139                 return Ordered.HIGHEST_PRECEDENCE;
 140         }
 141
 142         public void setSource(ExecutionFlowGeneratorSource source) {
 143                 this.source = source;
 144         }
 145
 146         public void setRunnableFactory(RunnableFactory runnableFactory) {
 147                 this.runnableFactory = runnableFactory;
 148         }
 149
 150         public void setExecutionContextBeanName(String executionContextBeanName) {
 151                 this.executionContextBeanName = executionContextBeanName;
 152         }
 153
 154         public void setContextValuesBeanName(String contextValuesBeanName) {
 155                 this.contextValuesBeanName = contextValuesBeanName;
 156         }
 157
 158         public void setFlowBeanNamesPrefix(String flowBeanNamesPrefix) {
 159                 this.flowBeanNamesPrefix = flowBeanNamesPrefix;
 160         }
 161 }