| 1 | /* |
| 2 | * Copyright 2006-2007 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 | |
| 17 | package org.springframework.batch.core.configuration.support; |
| 18 | |
| 19 | import org.springframework.beans.factory.config.BeanFactoryPostProcessor; |
| 20 | import org.springframework.beans.factory.config.ConfigurableListableBeanFactory; |
| 21 | import org.springframework.beans.factory.support.DefaultListableBeanFactory; |
| 22 | import org.springframework.context.ApplicationContext; |
| 23 | import org.springframework.context.ConfigurableApplicationContext; |
| 24 | import org.springframework.context.annotation.AnnotationConfigApplicationContext; |
| 25 | import org.springframework.context.support.GenericApplicationContext; |
| 26 | import org.springframework.context.support.GenericXmlApplicationContext; |
| 27 | import org.springframework.core.io.Resource; |
| 28 | import org.springframework.util.Assert; |
| 29 | import org.springframework.util.StringUtils; |
| 30 | |
| 31 | import java.io.IOException; |
| 32 | import java.util.ArrayList; |
| 33 | import java.util.Arrays; |
| 34 | import java.util.List; |
| 35 | |
| 36 | /** |
| 37 | * {@link ApplicationContextFactory} implementation that takes a parent context and a path to the context to create. |
| 38 | * When createApplicationContext method is called, the child {@link ApplicationContext} will be returned. The child |
| 39 | * context is not re-created every time it is requested, it is lazily initialized and cached. Clients should ensure that |
| 40 | * it is closed when it is no longer needed. |
| 41 | * |
| 42 | */ |
| 43 | public class GenericApplicationContextFactory extends AbstractApplicationContextFactory { |
| 44 | |
| 45 | /** |
| 46 | * Create an application context factory for the resource specified. The resource can be an actual {@link Resource}, |
| 47 | * in which case it will be interpreted as an XML file, or it can be a @Configuration class, or a package name. |
| 48 | * All types must be the same (mixing XML with a java package for example is not allowed and will result in an |
| 49 | * {@link java.lang.IllegalArgumentException}). |
| 50 | * |
| 51 | * @param resources some resources (XML configuration files, @Configuration classes or java packages to scan) |
| 52 | */ |
| 53 | public GenericApplicationContextFactory(Object... resources) { |
| 54 | super(resources); |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * @see AbstractApplicationContextFactory#createApplicationContext(ConfigurableApplicationContext, Object...) |
| 59 | */ |
| 60 | @Override |
| 61 | protected ConfigurableApplicationContext createApplicationContext(ConfigurableApplicationContext parent, |
| 62 | Object... resources) { |
| 63 | ConfigurableApplicationContext context; |
| 64 | |
| 65 | if (allObjectsOfType(resources, Resource.class)) { |
| 66 | context = new ResourceXmlApplicationContext(parent, resources); |
| 67 | } else if (allObjectsOfType(resources, Class.class)) { |
| 68 | context = new ResourceAnnotationApplicationContext(parent, resources); |
| 69 | } else if (allObjectsOfType(resources, String.class)) { |
| 70 | context = new ResourceAnnotationApplicationContext(parent, resources); |
| 71 | } else { |
| 72 | List<Class<?>> types = new ArrayList<Class<?>>(); |
| 73 | for (Object resource : resources) { |
| 74 | types.add(resource.getClass()); |
| 75 | } |
| 76 | throw new IllegalArgumentException("No application context could be created for resource types: " |
| 77 | + Arrays.toString(types.toArray())); |
| 78 | } |
| 79 | |
| 80 | return context; |
| 81 | } |
| 82 | |
| 83 | private boolean allObjectsOfType(Object[] objects, Class<?> type) { |
| 84 | for (Object object : objects) { |
| 85 | if (!type.isInstance(object)) { |
| 86 | return false; |
| 87 | } |
| 88 | } |
| 89 | return true; |
| 90 | } |
| 91 | |
| 92 | private abstract class ApplicationContextHelper { |
| 93 | |
| 94 | private final DefaultListableBeanFactory parentBeanFactory; |
| 95 | |
| 96 | private final ConfigurableApplicationContext parent; |
| 97 | |
| 98 | public ApplicationContextHelper(ConfigurableApplicationContext parent, GenericApplicationContext context, |
| 99 | Object... config) { |
| 100 | this.parent = parent; |
| 101 | if (parent != null) { |
| 102 | Assert.isTrue(parent.getBeanFactory() instanceof DefaultListableBeanFactory, |
| 103 | "The parent application context must have a bean factory of type DefaultListableBeanFactory"); |
| 104 | parentBeanFactory = (DefaultListableBeanFactory) parent.getBeanFactory(); |
| 105 | } |
| 106 | else { |
| 107 | parentBeanFactory = null; |
| 108 | } |
| 109 | context.setParent(parent); |
| 110 | context.setId(generateId(config)); |
| 111 | loadConfiguration(config); |
| 112 | prepareContext(parent, context); |
| 113 | } |
| 114 | |
| 115 | protected abstract String generateId(Object... config); |
| 116 | |
| 117 | protected abstract void loadConfiguration(Object... config); |
| 118 | |
| 119 | protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) { |
| 120 | if (parentBeanFactory != null) { |
| 121 | GenericApplicationContextFactory.this.prepareBeanFactory(parentBeanFactory, beanFactory); |
| 122 | for (Class<? extends BeanFactoryPostProcessor> cls : getBeanFactoryPostProcessorClasses()) { |
| 123 | for (String name : parent.getBeanNamesForType(cls)) { |
| 124 | beanFactory.registerSingleton(name, (parent.getBean(name))); |
| 125 | } |
| 126 | } |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | } |
| 131 | |
| 132 | private final class ResourceXmlApplicationContext extends GenericXmlApplicationContext { |
| 133 | |
| 134 | private final ApplicationContextHelper helper; |
| 135 | |
| 136 | /** |
| 137 | * @param parent |
| 138 | */ |
| 139 | public ResourceXmlApplicationContext(ConfigurableApplicationContext parent, Object... resources) { |
| 140 | helper = new ApplicationContextHelper(parent, this, resources) { |
| 141 | @Override |
| 142 | protected String generateId(Object... configs) { |
| 143 | Resource[] resources = Arrays.copyOfRange(configs, 0, configs.length, Resource[].class); |
| 144 | try { |
| 145 | List<String> uris = new ArrayList<String>(); |
| 146 | for (Resource resource : resources) { |
| 147 | uris.add(resource.getURI().toString()); |
| 148 | } |
| 149 | return StringUtils.collectionToCommaDelimitedString(uris); |
| 150 | } |
| 151 | catch (IOException e) { |
| 152 | return Arrays.toString(resources); |
| 153 | } |
| 154 | } |
| 155 | @Override |
| 156 | protected void loadConfiguration(Object... configs) { |
| 157 | Resource[] resources = Arrays.copyOfRange(configs, 0, configs.length, Resource[].class); |
| 158 | load(resources); |
| 159 | } |
| 160 | }; |
| 161 | refresh(); |
| 162 | } |
| 163 | |
| 164 | @Override |
| 165 | protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) { |
| 166 | super.prepareBeanFactory(beanFactory); |
| 167 | helper.prepareBeanFactory(beanFactory); |
| 168 | } |
| 169 | |
| 170 | @Override |
| 171 | public String toString() { |
| 172 | return "ResourceXmlApplicationContext:" + getId(); |
| 173 | } |
| 174 | |
| 175 | } |
| 176 | |
| 177 | private final class ResourceAnnotationApplicationContext extends AnnotationConfigApplicationContext { |
| 178 | |
| 179 | private final ApplicationContextHelper helper; |
| 180 | |
| 181 | public ResourceAnnotationApplicationContext(ConfigurableApplicationContext parent, Object... resources) { |
| 182 | helper = new ApplicationContextHelper(parent, this, resources) { |
| 183 | @Override |
| 184 | protected String generateId(Object... configs) { |
| 185 | if (allObjectsOfType(configs, Class.class)) { |
| 186 | Class<?>[] types = Arrays.copyOfRange(configs, 0, configs.length, Class[].class); |
| 187 | List<String> names = new ArrayList<String>(); |
| 188 | for (Class<?> type : types) { |
| 189 | names.add(type.getName()); |
| 190 | } |
| 191 | return StringUtils.collectionToCommaDelimitedString(names); |
| 192 | } else { |
| 193 | return Arrays.toString(configs); |
| 194 | } |
| 195 | } |
| 196 | @Override |
| 197 | protected void loadConfiguration(Object... configs) { |
| 198 | if (allObjectsOfType(configs, Class.class)) { |
| 199 | Class<?>[] types = Arrays.copyOfRange(configs, 0, configs.length, Class[].class); |
| 200 | register(types); |
| 201 | } else { |
| 202 | String[] pkgs = Arrays.copyOfRange(configs, 0, configs.length, String[].class); |
| 203 | scan(pkgs); |
| 204 | } |
| 205 | } |
| 206 | }; |
| 207 | refresh(); |
| 208 | } |
| 209 | |
| 210 | @Override |
| 211 | protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) { |
| 212 | super.prepareBeanFactory(beanFactory); |
| 213 | helper.prepareBeanFactory(beanFactory); |
| 214 | } |
| 215 | |
| 216 | @Override |
| 217 | public String toString() { |
| 218 | return "ResourceAnnotationApplicationContext:" + getId(); |
| 219 | } |
| 220 | |
| 221 | } |
| 222 | |
| 223 | } |