runtime/InstantiationManager.java

   1 package org.argeo.slc.runtime;
   2
   3 import java.util.Stack;
   4
   5 import org.apache.commons.logging.Log;
   6 import org.apache.commons.logging.LogFactory;
   7 import org.argeo.slc.SlcException;
   8 import org.argeo.slc.execution.ExecutionFlow;
   9 import org.argeo.slc.execution.ExecutionSpecAttribute;
  10 import org.argeo.slc.execution.RefSpecAttribute;
  11 import org.argeo.slc.primitive.PrimitiveSpecAttribute;
  12 import org.argeo.slc.primitive.PrimitiveUtils;
  13
  14 /** Manage parameters that need to be set during the instantiation of a flow */
  15 public class InstantiationManager {
  16
  17         private final static Log log = LogFactory
  18                         .getLog(InstantiationManager.class);
  19
  20         private ThreadLocal<Stack<ExecutionFlow>> flowStack = new ThreadLocal<Stack<ExecutionFlow>>();
  21
  22         public Object createRef(String name) {
  23
  24                 if ((flowStack.get() == null) || flowStack.get().empty()) {
  25                         throw new SlcException("No flow is currently initializing."
  26                                         + " Declare ParameterRef as inner beans or prototypes.");
  27                 }
  28
  29                 return getInitializingFlowParameter(name);
  30         }
  31
  32         public void flowInitializationStarted(ExecutionFlow flow, String flowName) {
  33                 // set the flow name if it is DefaultExecutionFlow
  34                 if (flow instanceof DefaultExecutionFlow) {
  35                         ((DefaultExecutionFlow) flow).setName(flowName);
  36                 }
  37
  38                 if (log.isTraceEnabled())
  39                         log.trace("Start initialization of " + flow.hashCode() + " ("
  40                                         + flow + " - " + flow.getClass() + ")");
  41
  42                 // log.info("# flowInitializationStarted " + flowName);
  43                 // create a stack for this thread if there is none
  44                 if (flowStack.get() == null) {
  45                         flowStack.set(new Stack<ExecutionFlow>());
  46                 }
  47                 flowStack.get().push(flow);
  48         }
  49
  50         public void flowInitializationFinished(ExecutionFlow flow, String flowName) {
  51                 if (log.isTraceEnabled())
  52                         log.trace("Finish initialization of " + flow.hashCode() + " ("
  53                                         + flow + " - " + flow.getClass() + ")");
  54
  55                 if (flowStack.get() != null) {
  56                         ExecutionFlow registeredFlow = flowStack.get().pop();
  57                         if (registeredFlow != null) {
  58                                 if (!flow.getName().equals(registeredFlow.getName()))
  59                                         throw new SlcException("Current flow is " + flow);
  60                                 // log.info("# flowInitializationFinished " + flowName);
  61                                 // initializingFlow.set(null);
  62                         }
  63                 } else {
  64                         // happens for flows imported as services
  65                         log.warn("flowInitializationFinished - Flow Stack is null");
  66                 }
  67         }
  68
  69         protected ExecutionFlow findInitializingFlowWithParameter(String key) {
  70                 if ((flowStack.get() == null) || flowStack.get().empty())
  71                         throw new SlcException("No initializing flow available.");
  72
  73                 // first look in the outer flow (that may override parameters)
  74                 for (int i = 0; i < flowStack.get().size(); i++) {
  75                         if (flowStack.get().elementAt(i).isSetAsParameter(key)) {
  76                                 return flowStack.get().elementAt(i);
  77                         }
  78                 }
  79                 throw new SlcException("Key " + key + " is not set as parameter in "
  80                                 + flowStack.get().firstElement().toString() + " (stack size="
  81                                 + flowStack.get().size() + ")");
  82
  83         }
  84
  85         public Object getInitializingFlowParameter(String key) {
  86                 return findInitializingFlowWithParameter(key).getParameter(key);
  87         }
  88
  89         public Class<?> getInitializingFlowParameterClass(String key) {
  90                 ExecutionSpecAttribute attr = findInitializingFlowWithParameter(key)
  91                                 .getExecutionSpec().getAttributes().get(key);
  92                 if (attr instanceof RefSpecAttribute)
  93                         return ((RefSpecAttribute) attr).getTargetClass();
  94                 else if (attr instanceof PrimitiveSpecAttribute) {
  95                         String type = ((PrimitiveSpecAttribute) attr).getType();
  96                         Class<?> clss = PrimitiveUtils.typeAsClass(type);
  97                         if (clss == null)
  98                                 throw new SlcException("Cannot convert type " + type
  99                                                 + " to class.");
 100                         return clss;
 101                 } else
 102                         return null;
 103         }
 104
 105         public Boolean isInFlowInitialization() {
 106                 return (flowStack.get() != null) && !flowStack.get().empty();
 107         }
 108 }