Java tutorial
/* * Copyright 2006-2010 the original author or authors. * * 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.springframework.amqp.rabbit.stocks.web; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Properties; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.amqp.core.AmqpTemplate; import org.springframework.amqp.rabbit.stocks.context.RefreshScope; import org.springframework.data.keyvalue.redis.core.RedisOperations; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.context.request.WebRequest; /** * @author Dave Syer * */ @Controller public class EnvironmentController { private static Log logger = LogFactory.getLog(EnvironmentController.class); private RefreshScope refreshScope; private AmqpTemplate amqpTemplate; private RedisOperations<String, String> redisTemplate; private Properties environmentProperties = new Properties(); public void setAmqpTemplate(AmqpTemplate amqpTemplate) { this.amqpTemplate = amqpTemplate; } public void setRefreshScope(RefreshScope refreshScope) { this.refreshScope = refreshScope; } public void setRedisTemplate(RedisOperations<String, String> redisTemplate) { this.redisTemplate = redisTemplate; } /** * @param properties the envProperties to set */ public void setEnvironmentProperties(Properties properties) { this.environmentProperties = properties; } /** * Get the system properties (key value "system") and the OS environment (key value "host") if available and the * persistent back-end (key value "env" if present). * * @return the system properties and OS environment */ @RequestMapping(value = "/env", method = RequestMethod.GET) @ResponseBody public Map<String, Properties> env() { Map<String, Properties> model = new HashMap<String, Properties>(); model.put("system", getSystemProperties()); model.put("host", getHostProperties()); model.put("env", environmentProperties); return model; } /** * Use this endpoint to refresh the cron trigger that is used to send market data to the broker. It builds a refresh * request and sends it to the broker using the AMQP template provided. * * @param bean a bean id * @return a refresh request object (as information for the caller) * * @see #handleRefresh(RefreshRequest) a handler for the request generated here */ @RequestMapping(value = "/refresh/{bean}", method = RequestMethod.POST) @ResponseBody public RefreshRequest refresh(@PathVariable String bean, WebRequest webRequest) { RefreshRequest request = new RefreshRequest(); Properties updates = new Properties(); Properties oldValues = new Properties(); for (Iterator<String> keys = webRequest.getParameterNames(); keys.hasNext();) { String key = keys.next(); updates.setProperty(key, webRequest.getParameter(key)); String value = environmentProperties.getProperty(key); if (value != null) { oldValues.setProperty(key, value); } } request.setUpdates(updates); request.setOldValues(oldValues); request.setBeanName(bean); if (amqpTemplate != null) { amqpTemplate.convertAndSend(request); } return request; } /** * Set some system properties and refresh a bean in the application context (provided it is in refresh scope). * * @param request a refresh request */ public void handleRefresh(RefreshRequest request) { logger.info("Handling refresh: " + request); String name = request.getBeanName(); Properties updates = request.getUpdates(); for (String property : updates.stringPropertyNames()) { String old = environmentProperties.getProperty(property); String update = updates.getProperty(property); if (update.length() > 0 && !update.equals(old)) { environmentProperties.setProperty(property, update); if (redisTemplate != null) { redisTemplate.boundValueOps("env." + property).set(update); } } } if (name != null && refreshScope != null) { refreshScope.refresh(name); } } private Properties getSystemProperties() { Properties env = new Properties(); try { env.putAll(System.getProperties()); } catch (Exception e) { logger.warn("Could not obtain System properties", e); } return env; } private Properties getHostProperties() { Properties env = new Properties(); try { Map<String, String> values = System.getenv(); for (String key : values.keySet()) { env.setProperty(key, values.get(key)); } } catch (Exception e) { logger.warn("Could not obtain OS environment", e); } return env; } public static class RefreshRequest { private String beanName; private Properties updates = new Properties(); private Properties oldValues = new Properties(); public String getBeanName() { return beanName; } public void setBeanName(String beanName) { this.beanName = beanName; } public Properties getUpdates() { return updates; } public Properties getOldValues() { return oldValues; } public void setOldValues(Properties oldValues) { this.oldValues = oldValues; } public void setUpdates(Properties oldValues) { this.updates = oldValues; } @Override public String toString() { return "RefreshRequest [beanName=" + beanName + ", updates=" + updates + ", oldValues=" + oldValues + "]"; } } }