wamblee.org Git - utils/blob - system/spring/src/main/java/org/wamblee/system/spring/SpringComponent.java

   1 /*
   2  * Copyright 2007 the original author or authors.
   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.wamblee.system.spring;
  17
  18 import java.util.HashMap;
  19 import java.util.Map;
  20 import java.util.Properties;
  21
  22 import org.springframework.beans.MutablePropertyValues;
  23 import org.springframework.beans.factory.config.BeanDefinition;
  24 import org.springframework.beans.factory.config.ConstructorArgumentValues;
  25 import org.springframework.beans.factory.support.RootBeanDefinition;
  26 import org.springframework.context.support.AbstractApplicationContext;
  27 import org.springframework.context.support.ClassPathXmlApplicationContext;
  28 import org.springframework.context.support.GenericApplicationContext;
  29 import org.wamblee.system.core.AbstractComponent;
  30 import org.wamblee.system.core.DefaultScope;
  31 import org.wamblee.system.core.ProvidedInterface;
  32 import org.wamblee.system.core.RequiredInterface;
  33 import org.wamblee.system.core.Scope;
  34 import org.wamblee.system.core.SystemAssemblyException;
  35
  36 /**
  37  * Represents a system configured based on spring. The spring config files that
  38  * are configured should not contain any PropertyPlaceholderConfigurer objects.
  39  *
  40  * @author Erik Brakkee
  41  */
  42 public class SpringComponent extends AbstractComponent<Scope> {
  43
  44         private static final String CONTEXT_KEY = "context";
  45
  46         static final ThreadLocal<SpringComponent> THIS = new ThreadLocal<SpringComponent>();
  47         static final ThreadLocal<Scope> SCOPE = new ThreadLocal<Scope>();
  48
  49         private Properties properties;
  50         private String[] configFiles;
  51         private Map<String, ProvidedInterface> provided;
  52         private Map<RequiredInterface, String> required;
  53         private Map<String, Properties> propertyObjects;
  54
  55         /**
  56          * Constructs a spring system.
  57          *
  58          * @param aName
  59          *            Name of the system.
  60          * @param aConfigFil
  61          *            Spring config files to read.
  62          * @param aProvided
  63          *            Map of bean name to service descriptor describing the bean
  64          *            names that the spring config files use for each required
  65          *            service.
  66          * @param aRequired
  67          *            Map of bean name to service descriptor describing the bean
  68          *            names that the spring config files use for each required
  69          *            service.
  70          */
  71         public SpringComponent(String aName, String[] aConfigFiles,
  72                         Map<String, ProvidedInterface> aProvided,
  73                         Map<RequiredInterface, String> aRequired) {
  74                 super(aName, aProvided.values().toArray(new ProvidedInterface[0]),
  75                                 aRequired.keySet().toArray(new RequiredInterface[0]));
  76                 properties = new Properties();
  77                 configFiles = aConfigFiles;
  78                 provided = aProvided;
  79                 required = aRequired;
  80                 propertyObjects = new HashMap<String, Properties>();
  81
  82         }
  83
  84         /**
  85          * Must be called to make a property available in the application context.
  86          *
  87          * @param aKey
  88          *            Property key.
  89          * @param aValue
  90          *            Property value.
  91          */
  92         public void setProperty(String aKey, String aValue) {
  93                 properties.put(aKey, aValue);
  94         }
  95
  96         public void addProperties(Properties aProperties) {
  97                 for (Object key : aProperties.keySet()) {
  98                         setProperty((String) key, aProperties.getProperty((String) key));
  99                 }
 100         }
 101
 102         public void addProperties(String aBeanname, Properties aProperties) {
 103             propertyObjects.put(aBeanname, aProperties);
 104         }
 105
 106         public Properties getProperties(String aBeanname) {
 107             return propertyObjects.get(aBeanname);
 108         }
 109
 110         @Override
 111         protected Scope doStart(Scope aExternalScope) {
 112
 113                 SpringComponent old = THIS.get();
 114                 Scope oldScope = SCOPE.get();
 115                 THIS.set(this);
 116                 Scope scope = new DefaultScope(getProvidedInterfaces().toArray(new ProvidedInterface[0]), aExternalScope);
 117                 SCOPE.set(scope);
 118                 try {
 119                         GenericApplicationContext parentContext = new GenericApplicationContext();
 120
 121                         registerRequiredServices(parentContext);
 122                         registerPropertyObjects(parentContext);
 123
 124                         parentContext.refresh();
 125
 126                         System.out.println("Parent context " + parentContext);
 127
 128                         AbstractApplicationContext context = parseConfigFiles(parentContext);
 129
 130                         context
 131                                         .addBeanFactoryPostProcessor(new PropertySetter(properties));
 132                         context.refresh();
 133
 134                         exposeProvidedServices(context, aExternalScope);
 135
 136                         scope.put(CONTEXT_KEY, context);
 137                         return scope;
 138                 } catch (Exception e) {
 139                         throw new SystemAssemblyException(
 140                                         "Failed to assemble spring system " + getName(), e);
 141                 } finally {
 142                         THIS.set(old);
 143                         SCOPE.set(oldScope);
 144                 }
 145         }
 146
 147         private void exposeProvidedServices(AbstractApplicationContext aContext, Scope aScope) {
 148                 // Call addService for each provided service.
 149
 150                 for (String name : provided.keySet()) {
 151                         Object svc = aContext.getBean(name);
 152                         if (svc == null) {
 153                                 throw new IllegalArgumentException(getQualifiedName() + ": service '"
 154                                                 + name + "' is null");
 155                         }
 156                         addInterface(provided.get(name), svc, aScope);
 157                         System.out.println("addService " + provided.get(name) + " " + svc);
 158                 }
 159         }
 160
 161         private AbstractApplicationContext parseConfigFiles(GenericApplicationContext aParentContext) {
 162                 // Parse spring config files
 163
 164                 return new ClassPathXmlApplicationContext((String[]) configFiles,
 165                                 false, aParentContext);
 166         }
 167
 168         private void registerRequiredServices(GenericApplicationContext aParentContext) {
 169                 // Register required services in a parent context
 170                 for (RequiredInterface requiredIntf: getRequiredInterfaces()) {
 171                         String beanName = required.get(requiredIntf);
 172                         if ( beanName != null && beanName.length() > 0) {
 173                             ConstructorArgumentValues cargs = new ConstructorArgumentValues();
 174                     cargs.addGenericArgumentValue(requiredIntf.getName());
 175                     BeanDefinition definition = new RootBeanDefinition(
 176                             RequiredServiceBean.class, cargs,
 177                             new MutablePropertyValues());
 178                     aParentContext.registerBeanDefinition(beanName, definition);
 179                         } else {
 180                             // The required interface is not required by the spring config but by the sub-class directly.
 181                         }
 182                 }
 183         }
 184
 185         private void registerPropertyObjects(GenericApplicationContext aParentContext) {
 186         for (String beanName: propertyObjects.keySet()) {
 187             ConstructorArgumentValues cargs = new ConstructorArgumentValues();
 188             cargs.addGenericArgumentValue(PropertySetter.createPropertyFile(propertyObjects.get(beanName)));
 189             BeanDefinition definition = new RootBeanDefinition(
 190                     ConfiguredProperties.class, cargs,
 191                     new MutablePropertyValues());
 192             aParentContext.registerBeanDefinition(beanName, definition);
 193         }
 194     }
 195
 196
 197         @Override
 198         protected void doStop(Scope aRuntime) {
 199                 AbstractApplicationContext context = (AbstractApplicationContext)aRuntime.get(CONTEXT_KEY);
 200                 context.close();
 201         }
 202 }