org.apache.james.container.spring.lifecycle.ConfigurationProviderImpl Maven / Gradle / Ivy
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package org.apache.james.container.spring.lifecycle;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.configuration2.HierarchicalConfiguration;
import org.apache.commons.configuration2.XMLConfiguration;
import org.apache.commons.configuration2.builder.FileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.fluent.Parameters;
import org.apache.commons.configuration2.convert.DisabledListDelimiterHandler;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.io.FileHandler;
import org.apache.commons.configuration2.tree.ImmutableNode;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ResourceLoaderAware;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
/**
* Register Configuration and act as Configuration Provider.
*/
public class ConfigurationProviderImpl implements ConfigurationProvider, ResourceLoaderAware, InitializingBean {
private static final String CONFIGURATION_FILE_SUFFIX = ".xml";
/**
* A map of loaded configuration per bean.
*/
private final Map> configurations = new HashMap<>();
/**
* Mappings for bean names associated with their related
* "resourceName.configPart" pattern.
* The resourceName is the XML configuration file name, the configPart is
* the tag within the XML to look for.
*/
private Map configurationMappings;
/**
* The Spring Resource Loader. Injected via setResourceLoader because this
* class implements ResourceLoaderAware.
*/
private ResourceLoader loader;
/**
* Inject the needed configuration mappings.
*
* @param configurationMappings
*/
public void setConfigurationMappings(Map configurationMappings) {
this.configurationMappings = configurationMappings;
}
@Override
public void registerConfiguration(String beanName, HierarchicalConfiguration conf) {
configurations.put(beanName, conf);
}
/**
* Responsible to register additional configurations for the injected
* configurationMappings.
*/
@Override
public void afterPropertiesSet() throws Exception {
if (configurationMappings != null) {
for (String key : configurationMappings.keySet()) {
String value = configurationMappings.get(key);
registerConfiguration(key, getConfiguration(value));
}
}
}
@Override
public HierarchicalConfiguration getConfiguration(String name) throws ConfigurationException {
HierarchicalConfiguration conf = configurations.get(name);
// Simply return the configuration if it is already loaded.
if (conf != null) {
return conf;
} else {
// Load the configuration.
// Compute resourceName and configPart (if any, configPart can
// remain null).
int i = name.indexOf(".");
String resourceName;
String configPart = null;
if (i > -1) {
resourceName = name.substring(0, i);
configPart = name.substring(i + 1);
} else {
resourceName = name;
}
Resource resource = loader.getResource(getConfigPrefix() + resourceName + CONFIGURATION_FILE_SUFFIX);
if (resource.exists()) {
try {
HierarchicalConfiguration config = getConfig(resource);
if (configPart != null) {
return config.configurationAt(configPart);
} else {
return config;
}
} catch (Exception e) {
throw new ConfigurationException("Unable to load configuration for component " + name, e);
}
}
}
// Configuration was not loaded, throw exception.
throw new ConfigurationException("Unable to load configuration for component " + name);
}
@Override
public void setResourceLoader(ResourceLoader loader) {
this.loader = loader;
}
/**
* Load the xmlConfiguration from the given resource.
*
* @param r
* @return
* @throws ConfigurationException
* @throws IOException
*/
private XMLConfiguration getConfig(Resource r) throws ConfigurationException, IOException {
FileBasedConfigurationBuilder builder = new FileBasedConfigurationBuilder<>(XMLConfiguration.class)
.configure(new Parameters()
.xml()
.setListDelimiterHandler(new DisabledListDelimiterHandler()));
XMLConfiguration xmlConfiguration = builder.getConfiguration();
FileHandler fileHandler = new FileHandler(xmlConfiguration);
fileHandler.load(r.getInputStream());
return xmlConfiguration;
}
/**
* Return the configuration prefix to load the configuration. In this case
* it is classpath:, but could be also file://conf/
*
* @return prefix
*/
private String getConfigPrefix() {
return "classpath:";
}
}