ContainerLoader类实现StartupLoader接口，目的是装入各种Container容器。
/**
* An OFBiz container. A container can be thought of as a background process.
*
* <p>
* When OFBiz starts, the main thread will create the <code>Container</code> instance and
* then call the container's <code>init</code> method. If the method returns without
* throwing an exception the container will be added to a list of initialized containers.
* After all instances have been created and initialized, the main thread will call the
* <code>start</code> method of each container in the list. When OFBiz shuts down, a
* separate shutdown thread will call the <code>stop</code> method of each container.
* Implementations should anticipate asynchronous calls to the methods by different
* threads.
* </p>
*
* <p>Containers might be loaded more than once (have more than one instance).<p>
*/
public interface Container { /** Initialize the container. This method must not block - implementations
* should initialize internal structures and then return.
*
* @param args Command-line arguments.
* @param name Unique name of the container's instance.
* @param configFile Location of the configuration file used to load this container.
* @throws ContainerException If an error was encountered. Throwing this exception
* will halt container loading, so it should be thrown only when other containers
* might depend on this one.
*/
public void init(String[] args, String name, String configFile) throws ContainerException; /**
* Start the container process. This method must not block - implementations
* that require thread blocking must create a separate thread and then return.
*
* @return <code>true</code> if the process started.
* @throws ContainerException If an error was encountered.
*/
public boolean start() throws ContainerException; /**
* Stop the container process. This method must not block.
*
* @throws ContainerException If an error was encountered.
*/
public void stop() throws ContainerException; /**
* Return the container name.
*
* @return Name of the container's instance.
*/
public String getName();
}
ContainerLoader会以三种方式寻找Container。第一种方式从配置文件中找，默认的配置文件是framework/base/config/ofbiz-containers.xml。第二种方式找组件Component总定义的容器。第三种方式找hot-deploy容器，这也是一个配置文件hot-deploy-containers.xml。
ofbiz-containers.xml定义了整个OFBIZ最重要的ComponentContainer容器，该容器载入所有的Component。
<ofbiz-containers xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="http://ofbiz.apache.org/dtds/ofbiz-containers.xsd"> <!-- load the ofbiz component container (always first) -->
<container name="component-container" loaders="main,rmi,pos,install" class="org.ofbiz.base.container.ComponentContainer"/> <container name="component-container-test" loaders="test" class="org.ofbiz.base.container.ComponentContainer">
<property name="ofbiz.instrumenterClassName" value="org.ofbiz.base.config.CoberturaInstrumenter"/>
<property name="ofbiz.instrumenterFile" value="runtime/logs/cobertura-components.dat"/>
</container> <container name="component-container-limited" loaders="limited" class="org.ofbiz.base.container.ComponentContainer">
<property name="update-classpath" value="false"/>
</container> <container name="component-container" loaders="testlist" class="org.ofbiz.base.container.JustLoadComponentsContainer"/> </ofbiz-containers>
ContainerLoader首先载入ofbiz-containers.xml中的容器：
this.loadedContainers.clear(); // get this loader's configuration file
// default: framework/base/config/ofbiz-containers.xml
this.configFile = config.containerConfig; Collection<ContainerConfig.Container> containers = null;
try {
containers = ContainerConfig.getContainers(configFile);
} catch (ContainerException e) {
throw new StartupException(e);
} for (ContainerConfig.Container containerCfg : containers) {
if (this.unloading) {
return;
}
boolean matchingLoaderFound = false;
if (UtilValidate.isEmpty(containerCfg.loaders) && UtilValidate.isEmpty(loaders)) {
matchingLoaderFound = true;
} else {
for (String loader: loaders) {
if (UtilValidate.isEmpty(containerCfg.loaders) || containerCfg.loaders.contains(loader)) {
matchingLoaderFound = true;
break;
}
}
}
if (matchingLoaderFound) {
Debug.logInfo("Loading container: " + containerCfg.name, module);
Container tmpContainer = loadContainer(containerCfg, args);
this.loadedContainers.add(tmpContainer);
Debug.logInfo("Loaded container: " + containerCfg.name, module);
}
} private Container loadContainer(ContainerConfig.Container containerCfg, String[] args) throws StartupException {
// load the container class
ClassLoader loader = Thread.currentThread().getContextClassLoader();
if (loader == null) {
Debug.logWarning("Unable to get context classloader; using system", module);
loader = ClassLoader.getSystemClassLoader();
}
Class<?> containerClass = null;
try {
containerClass = loader.loadClass(containerCfg.className);
} catch (ClassNotFoundException e) {
throw new StartupException("Cannot locate container class", e);
}
if (containerClass == null) {
throw new StartupException("Component container class not loaded");
} // create a new instance of the container object
Container containerObj = null;
try {
containerObj = (Container) containerClass.newInstance();
} catch (InstantiationException e) {
throw new StartupException("Cannot create " + containerCfg.name, e);
} catch (IllegalAccessException e) {
throw new StartupException("Cannot create " + containerCfg.name, e);
} catch (ClassCastException e) {
throw new StartupException("Cannot create " + containerCfg.name, e);
} if (containerObj == null) {
throw new StartupException("Unable to create instance of component container");
} // initialize the container object
try {
containerObj.init(args, containerCfg.name, configFile);
} catch (ContainerException e) {
throw new StartupException("Cannot init() " + containerCfg.name, e);
} catch (java.lang.AbstractMethodError e) {
throw new StartupException("Cannot init() " + containerCfg.name, e);
} return containerObj;
}
然后载入Component中定义的容器：
List<ContainerConfig.Container> containersDefinedInComponents = ComponentConfig.getAllContainers();
for (ContainerConfig.Container containerCfg: containersDefinedInComponents) {
boolean matchingLoaderFound = false;
if (UtilValidate.isEmpty(containerCfg.loaders) && UtilValidate.isEmpty(loaders)) {
matchingLoaderFound = true;
} else {
for (String loader: loaders) {
if (UtilValidate.isEmpty(containerCfg.loaders) || containerCfg.loaders.contains(loader)) {
matchingLoaderFound = true;
break;
}
}
}
if (matchingLoaderFound) {
Debug.logInfo("Loading component's container: " + containerCfg.name, module);
Container tmpContainer = loadContainer(containerCfg, args);
this.loadedContainers.add(tmpContainer);
Debug.logInfo("Loaded component's container: " + containerCfg.name, module);
}
}
第三步载入hot-deploy容器：
ClassLoader loader = Thread.currentThread().getContextClassLoader();
Enumeration<URL> resources;
try {
resources = loader.getResources("hot-deploy-containers.xml");
while (resources.hasMoreElements() && !this.unloading) {
URL xmlUrl = resources.nextElement();
Debug.logInfo("Loading hot-deploy containers from " + xmlUrl, module);
Collection<ContainerConfig.Container> hotDeployContainers = ContainerConfig.getContainers(xmlUrl);
for (ContainerConfig.Container containerCfg : hotDeployContainers) {
if (this.unloading) {
return;
}
Container tmpContainer = loadContainer(containerCfg, args);
this.loadedContainers.add(tmpContainer);
}
}
} catch (Exception e) {
Debug.logError(e, "Could not load hot-deploy-containers.xml", module);
throw new StartupException(e);
}
最后ContainerLoader启动时，执行所有Container的start()方法。
public synchronized void start() throws StartupException {
if (!this.loaded || this.unloading) {
throw new IllegalStateException("start() called on unloaded containers");
}
Debug.logInfo("[Startup] Starting containers...", module);
// start each container object
for (Container container: this.loadedContainers) {
if (this.unloading) {
return;
}
Debug.logInfo("Starting container " + container.getName(), module);
try {
container.start();
} catch (ContainerException e) {
throw new StartupException("Cannot start() " + container.getClass().getName(), e);
} catch (java.lang.AbstractMethodError e) {
throw new StartupException("Cannot start() " + container.getClass().getName(), e);
}
Debug.logInfo("Started container " + container.getName(), module);
}
}