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