org.argeo.slc.spring/src/org/argeo/slc/core/execution/InstantiationManager.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.slc.core.execution;
  17
  18 import java.util.Stack;
  19
  20 import org.apache.commons.logging.Log;
  21 import org.apache.commons.logging.LogFactory;
  22 import org.argeo.slc.SlcException;
  23 import org.argeo.slc.execution.ExecutionFlow;
  24 import org.argeo.slc.execution.ExecutionSpecAttribute;
  25 import org.argeo.slc.execution.RefSpecAttribute;
  26 import org.argeo.slc.primitive.PrimitiveSpecAttribute;
  27 import org.argeo.slc.primitive.PrimitiveUtils;
  28
  29 /** Manage parameters that need to be set during the instantiation of a flow */
  30 public class InstantiationManager {
  31
  32         private final static Log log = LogFactory
  33                         .getLog(InstantiationManager.class);
  34
  35         private ThreadLocal<Stack<ExecutionFlow>> flowStack = new ThreadLocal<Stack<ExecutionFlow>>();
  36
  37         public Object createRef(String name) {
  38
  39                 if ((flowStack.get() == null) || flowStack.get().empty()) {
  40                         throw new SlcException("No flow is currently initializing."
  41                                         + " Declare ParameterRef as inner beans or prototypes.");
  42                 }
  43
  44                 return getInitializingFlowParameter(name);
  45         }
  46
  47         public void flowInitializationStarted(ExecutionFlow flow, String flowName) {
  48                 // set the flow name if it is DefaultExecutionFlow
  49                 if (flow instanceof DefaultExecutionFlow) {
  50                         ((DefaultExecutionFlow) flow).setBeanName(flowName);
  51                 }
  52
  53                 if (log.isTraceEnabled())
  54                         log.trace("Start initialization of " + flow.hashCode() + " ("
  55                                         + flow + " - " + flow.getClass() + ")");
  56
  57                 // log.info("# flowInitializationStarted " + flowName);
  58                 // create a stack for this thread if there is none
  59                 if (flowStack.get() == null) {
  60                         flowStack.set(new Stack<ExecutionFlow>());
  61                 }
  62                 flowStack.get().push(flow);
  63         }
  64
  65         public void flowInitializationFinished(ExecutionFlow flow, String flowName) {
  66                 if (log.isTraceEnabled())
  67                         log.trace("Finish initialization of " + flow.hashCode() + " ("
  68                                         + flow + " - " + flow.getClass() + ")");
  69
  70                 if (flowStack.get() != null) {
  71                         ExecutionFlow registeredFlow = flowStack.get().pop();
  72                         if (registeredFlow != null) {
  73                                 if (!flow.getName().equals(registeredFlow.getName()))
  74                                         throw new SlcException("Current flow is " + flow);
  75                                 // log.info("# flowInitializationFinished " + flowName);
  76                                 // initializingFlow.set(null);
  77                         }
  78                 } else {
  79                         // happens for flows imported as services
  80                         log.warn("flowInitializationFinished - Flow Stack is null");
  81                 }
  82         }
  83
  84         protected ExecutionFlow findInitializingFlowWithParameter(String key) {
  85                 if ((flowStack.get() == null) || flowStack.get().empty())
  86                         throw new SlcException("No initializing flow available.");
  87
  88                 // first look in the outer flow (that may override parameters)
  89                 for (int i = 0; i < flowStack.get().size(); i++) {
  90                         if (flowStack.get().elementAt(i).isSetAsParameter(key)) {
  91                                 return flowStack.get().elementAt(i);
  92                         }
  93                 }
  94                 throw new SlcException("Key " + key + " is not set as parameter in "
  95                                 + flowStack.get().firstElement().toString() + " (stack size="
  96                                 + flowStack.get().size() + ")");
  97
  98         }
  99
 100         public Object getInitializingFlowParameter(String key) {
 101                 return findInitializingFlowWithParameter(key).getParameter(key);
 102         }
 103
 104         public Class<?> getInitializingFlowParameterClass(String key) {
 105                 ExecutionSpecAttribute attr = findInitializingFlowWithParameter(key)
 106                                 .getExecutionSpec().getAttributes().get(key);
 107                 if (attr instanceof RefSpecAttribute)
 108                         return ((RefSpecAttribute) attr).getTargetClass();
 109                 else if (attr instanceof PrimitiveSpecAttribute) {
 110                         String type = ((PrimitiveSpecAttribute) attr).getType();
 111                         Class<?> clss = PrimitiveUtils.typeAsClass(type);
 112                         if (clss == null)
 113                                 throw new SlcException("Cannot convert type " + type
 114                                                 + " to class.");
 115                         return clss;
 116                 } else
 117                         return null;
 118         }
 119
 120         public Boolean isInFlowInitialization() {
 121                 return (flowStack.get() != null) && !flowStack.get().empty();
 122         }
 123 }