/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.cloudstack.spring.module.model.impl;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.EmptyStackException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.Stack;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.UrlResource;
import org.springframework.util.StringUtils;
import org.apache.cloudstack.spring.module.context.ResourceApplicationContext;
import org.apache.cloudstack.spring.module.model.ModuleDefinition;
import org.apache.cloudstack.spring.module.model.ModuleDefinitionSet;
public class DefaultModuleDefinitionSet implements ModuleDefinitionSet {
private static final Logger log = LoggerFactory.getLogger(DefaultModuleDefinitionSet.class);
public static final String DEFAULT_CONFIG_RESOURCES = "DefaultConfigResources";
public static final String DEFAULT_CONFIG_PROPERTIES = "DefaultConfigProperties";
public static final String MODULES_EXCLUDE = "modules.exclude";
public static final String MODULES_INCLUDE_PREFIX = "modules.include.";
public static final String MODULE_PROPERITES = "ModuleProperties";
public static final String DEFAULT_CONFIG_XML = "defaults-context.xml";
String root;
Map<String, ModuleDefinition> modules;
Map<String, ApplicationContext> contexts = new HashMap<String, ApplicationContext>();
ApplicationContext rootContext = null;
Set<String> excludes = new HashSet<String>();
Properties configProperties = null;
public DefaultModuleDefinitionSet(Map<String, ModuleDefinition> modules, String root) {
super();
this.root = root;
this.modules = modules;
}
public void load() throws IOException {
if (!loadRootContext())
return;
printHierarchy();
loadContexts();
startContexts();
}
protected boolean loadRootContext() {
ModuleDefinition def = modules.get(root);
if (def == null)
return false;
ApplicationContext defaultsContext = getDefaultsContext();
rootContext = loadContext(def, defaultsContext);
return true;
}
protected void startContexts() {
withModule(new WithModule() {
@Override
public void with(ModuleDefinition def, Stack<ModuleDefinition> parents) {
try {
ApplicationContext context = getApplicationContext(def.getName());
try {
Runnable runnable = context.getBean("moduleStartup", Runnable.class);
log.info("Starting module [{}]", def.getName());
runnable.run();
} catch (BeansException e) {
// Ignore
}
} catch (EmptyStackException e) {
// The root context is already loaded, so ignore the exception
}
}
});
}
protected void loadContexts() {
withModule(new WithModule() {
@Override
public void with(ModuleDefinition def, Stack<ModuleDefinition> parents) {
try {
ApplicationContext parent = getApplicationContext(parents.peek().getName());
loadContext(def, parent);
} catch (EmptyStackException e) {
// The root context is already loaded, so ignore the exception
}
}
});
}
protected ApplicationContext loadContext(ModuleDefinition def, ApplicationContext parent) {
ResourceApplicationContext context = new ResourceApplicationContext();
context.setApplicationName("/" + def.getName());
Resource[] resources = getConfigResources(def.getName());
context.setConfigResources(resources);
context.setParent(parent);
context.setClassLoader(def.getClassLoader());
long start = System.currentTimeMillis();
if (log.isInfoEnabled()) {
for (Resource resource : resources) {
log.info("Loading module context [{}] from {}", def.getName(), resource);
}
}
context.refresh();
log.info("Loaded module context [{}] in {} ms", def.getName(), (System.currentTimeMillis() - start));
contexts.put(def.getName(), context);
return context;
}
protected boolean shouldLoad(ModuleDefinition def) {
return !excludes.contains(def.getName());
}
protected ApplicationContext getDefaultsContext() {
URL config = DefaultModuleDefinitionSet.class.getResource(DEFAULT_CONFIG_XML);
ResourceApplicationContext context = new ResourceApplicationContext(new UrlResource(config));
context.setApplicationName("/defaults");
context.refresh();
@SuppressWarnings("unchecked")
final List<Resource> resources = (List<Resource>)context.getBean(DEFAULT_CONFIG_RESOURCES);
withModule(new WithModule() {
@Override
public void with(ModuleDefinition def, Stack<ModuleDefinition> parents) {
for (Resource defaults : def.getConfigLocations()) {
resources.add(defaults);
}
}
});
configProperties = (Properties)context.getBean(DEFAULT_CONFIG_PROPERTIES);
for (Resource resource : resources) {
load(resource, configProperties);
}
for (Resource resource : (Resource[])context.getBean(MODULE_PROPERITES)) {
load(resource, configProperties);
}
parseExcludes();
return context;
}
protected void parseExcludes() {
for (String exclude : configProperties.getProperty(MODULES_EXCLUDE, "").trim().split("\\s*,\\s*")) {
if (StringUtils.hasText(exclude)) {
excludes.add(exclude);
}
}
for (String key : configProperties.stringPropertyNames()) {
if (key.startsWith(MODULES_INCLUDE_PREFIX)) {
String module = key.substring(MODULES_INCLUDE_PREFIX.length());
boolean include = configProperties.getProperty(key).equalsIgnoreCase("true");
if (!include) {
excludes.add(module);
}
}
}
}
protected void load(Resource resource, Properties props) {
InputStream is = null;
try {
if (resource.exists()) {
is = resource.getInputStream();
props.load(is);
}
} catch (IOException e) {
throw new IllegalStateException("Failed to load resource [" + resource + "]", e);
} finally {
IOUtils.closeQuietly(is);
}
}
protected void printHierarchy() {
withModule(new WithModule() {
@Override
public void with(ModuleDefinition def, Stack<ModuleDefinition> parents) {
log.info(String.format("Module Hierarchy:%" + ((parents.size() * 2) + 1) + "s%s", "", def.getName()));
}
});
}
protected void withModule(WithModule with) {
ModuleDefinition rootDef = modules.get(root);
withModule(rootDef, new Stack<ModuleDefinition>(), with);
}
protected void withModule(ModuleDefinition def, Stack<ModuleDefinition> parents, WithModule with) {
if (def == null)
return;
if (!shouldLoad(def)) {
log.info("Excluding context [{}] based on configuration", def.getName());
return;
}
with.with(def, parents);
parents.push(def);
for (ModuleDefinition child : def.getChildren()) {
withModule(child, parents, with);
}
parents.pop();
}
private static interface WithModule {
public void with(ModuleDefinition def, Stack<ModuleDefinition> parents);
}
@Configuration
public static class ConfigContext {
List<Resource> resources;
public ConfigContext(List<Resource> resources) {
super();
this.resources = resources;
}
@Bean(name = DEFAULT_CONFIG_RESOURCES)
public List<Resource> defaultConfigResources() {
return new ArrayList<Resource>();
}
}
@Override
public ApplicationContext getApplicationContext(String name) {
return contexts.get(name);
}
@Override
public Resource[] getConfigResources(String name) {
Set<Resource> resources = new LinkedHashSet<Resource>();
ModuleDefinition original = null;
ModuleDefinition def = original = modules.get(name);
if (def == null)
return new Resource[] {};
resources.addAll(def.getContextLocations());
while (def != null) {
resources.addAll(def.getInheritableContextLocations());
def = modules.get(def.getParentName());
}
resources.addAll(original.getOverrideContextLocations());
return resources.toArray(new Resource[resources.size()]);
}
@Override
public ModuleDefinition getModuleDefinition(String name) {
return modules.get(name);
}
}