Java tutorial
/** * Copyright (C) 2014 JBoss Inc * * Licensed 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.dashbuilder.config; import java.io.IOException; import java.io.InputStream; import java.lang.reflect.Type; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Properties; import javax.annotation.PostConstruct; import javax.enterprise.context.ApplicationScoped; import javax.enterprise.inject.Produces; import javax.enterprise.inject.spi.Annotated; import javax.enterprise.inject.spi.InjectionPoint; import javax.inject.Inject; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; /** * Producer class for primitive fields annotated with @Config */ @ApplicationScoped public class ConfigReader { @Inject private Logger log; private volatile Properties globalProperties; private volatile Map<String, Properties> beanPropertyMap; public static final String beansConfigFile = "META-INF/beans.config"; @PostConstruct public void init() { try { globalProperties = new Properties(); beanPropertyMap = new HashMap<String, Properties>(); InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream(beansConfigFile); if (is != null) globalProperties.load(is); } catch (IOException ex) { throw new RuntimeException(ex); } } public @Produces @Config String readConfig(InjectionPoint p) { // Read from specific bean String beanKey = p.getMember().getDeclaringClass().getName(); Properties beanProperties = beanPropertyMap.get(beanKey); if (beanProperties == null) { beanPropertyMap.put(beanKey, beanProperties = new Properties()); try { InputStream is = Thread.currentThread().getContextClassLoader() .getResourceAsStream("META-INF/" + beanKey + ".config"); if (is != null) beanProperties.load(is); } catch (IOException ex) { throw new RuntimeException(ex); } } // Read from the bean config String configKey = p.getMember().getName(); String configValue = beanProperties.getProperty(configKey); if (configValue != null) return configValue; // Read from global - by the fully qualified class name and field name for (Type type : p.getBean().getTypes()) { configKey = ((Class) type).getName() + "." + p.getMember().getName(); configValue = globalProperties.getProperty(configKey); if (configValue != null) return configValue; // Try class name from System.properties configValue = System.getProperty(configKey); if (configValue != null) { log.info(String.format("System property: %s=%s", configKey, configValue)); return configValue; } // Try class simple name from System.properties configKey = ((Class) type).getSimpleName() + "." + p.getMember().getName(); configValue = System.getProperty(configKey); if (configValue != null) { log.info(String.format("System property: %s=%s", configKey, configValue)); return configValue; } } // Read from global - only by the field name configKey = p.getMember().getName(); configValue = globalProperties.getProperty(configKey); if (configValue != null) return configValue; // Return the default value if any. Annotated annotated = p.getAnnotated(); Config config = annotated.getAnnotation(Config.class); if (config != null) return config.value(); return null; } public @Produces @Config byte readPrimitiveByte(InjectionPoint p) { String val = readConfig(p); return Byte.parseByte(val); } public @Produces @Config short readPrimitiveShort(InjectionPoint p) { String val = readConfig(p); return Short.parseShort(val); } public @Produces @Config int readPrimitiveInt(InjectionPoint p) { String val = readConfig(p); return Integer.parseInt(val); } public @Produces @Config long readPrimitiveLong(InjectionPoint p) { String val = readConfig(p); return Long.parseLong(val); } public @Produces @Config boolean readPrimitiveBoolean(InjectionPoint p) { String val = readConfig(p); return Boolean.parseBoolean(val); } public @Produces @Config float readPrimitiveFloat(InjectionPoint p) { String val = readConfig(p); return Float.parseFloat(val); } public @Produces @Config double readPrimitiveDouble(InjectionPoint p) { String val = readConfig(p); return Double.parseDouble(val); } public @Produces @Config String[] readStringArray(InjectionPoint p) { String val = readConfig(p); String[] result = StringUtils.split(val, ","); for (int i = 0; i < result.length; i++) { result[i] = result[i].trim(); } return result; } public @Produces @Config java.util.List<String> readStringList(InjectionPoint p) { String val = readConfig(p); String[] array = StringUtils.split(val, ","); List<String> list = new ArrayList<String>(); for (int i = 0; i < array.length; i++) { list.add(array[i].trim()); } return list; } public @Produces @Config Map<String, String> readStringMap(InjectionPoint p) { String val = readConfig(p); Map<String, String> results = new HashMap<String, String>(); String[] rows = StringUtils.split(val, ","); for (int i = 0; i < rows.length; i++) { String row = rows[i].trim(); final String[] rowSplit = row.split("="); if (rowSplit.length != 2) throw new IllegalArgumentException("Illegal map entry '" + row + "'"); results.put(rowSplit[0].trim(), rowSplit[1].trim()); } return results; } public @Produces @Config Properties readProperties(InjectionPoint p) { String val = readConfig(p); Properties results = new Properties(); String[] rows = StringUtils.split(val, ","); for (int i = 0; i < rows.length; i++) { String row = rows[i].trim(); final String[] rowSplit = row.split("="); if (rowSplit.length != 2) throw new IllegalArgumentException("Illegal property entry '" + row + "'"); results.put(rowSplit[0].trim(), rowSplit[1].trim()); } return results; } }