spring读取配置文件优化

1、达到目的：根据tomcat的启动参数中配置不同的spring.profiles.active的值，读取不同环境的配置参数。

2、spring配置文件的代码：

<!-- 定义受环境影响易变的变量 --><bean id="propertyPlaceholderConfigurer" class="com.zhou..spring.util.config.DynamicServerConfig"><property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" /><property name="ignoreResourceNotFound" value="true" /><property name="locations"><list>    <value>classpath:config/system.devjunit.properties</value><value>classpath:config/system.development.properties</value><value>classpath:config/system.devzcb.properties</value><value>classpath:config/system.development02.properties</value><value>classpath:config/system.test.properties</value><value>classpath:config/system.testzcb.properties</value><value>classpath:config/system.test02.properties</value><value>classpath:config/system.uat.properties</value><value>classpath:config/system.uatzcb.properties</value><value>classpath:config/system.uattask.properties</value><value>classpath:config/system.run.properties</value><value>classpath:config/system.runzcb.properties</value><value>classpath:config/system.runtask.properties</value></list></property></bean>

3、DynamicServerConfig类的代码：

public class DynamicServerConfig extends PropertyPlaceholderConfigurer {/** * Set a location of a properties file to be loaded. * <p> * Can point to a classic properties file or to an XML file that follows JDK 1.5's properties XML format. */private boolean localOverride = false;private Properties[] localProperties;private Resource[] locations;private final PropertiesPersister propertiesPersister = new DefaultPropertiesPersister();private boolean ignoreResourceNotFound = false;/** * Set if failure to find the property resource should be ignored. True is appropriate if the properties file is * completely optional. Default is "false". */@Overridepublic void setIgnoreResourceNotFound(boolean ignoreResourceNotFound) {this.ignoreResourceNotFound = ignoreResourceNotFound;}/** * Set local properties, e.g. via the "props" tag in XML bean definitions. These can be considered defaults, to be * overridden by properties loaded from files. */@Overridepublic void setProperties(Properties properties) {this.localProperties = new Properties[] { properties };super.setProperties(properties);}/** * Set local properties, e.g. via the "props" tag in XML bean definitions, allowing for merging multiple properties * sets into one. */@Overridepublic void setPropertiesArray(Properties[] propertiesArray) {this.localProperties = propertiesArray;}@Overridepublic void setLocation(Resource location) {this.locations = new Resource[] { location };super.setLocation(location);}/** * Set locations of properties files to be loaded. * <p> * Can point to classic properties files or to XML files that follow JDK 1.5's properties XML format. */@Overridepublic void setLocations(Resource[] locations) {this.locations = locations;super.setLocations(locations);}/** * Set whether local properties override properties from files. Default is "false": properties from files override * local defaults. Can be switched to "true" to let local properties override defaults from files. */@Overridepublic void setLocalOverride(boolean localOverride) {this.localOverride = localOverride;}@Overridepublic Properties mergeProperties() throws IOException {Properties result = new Properties();if (this.localOverride) {// Load properties from file upfront, to let local properties// override.loadProperties(result);}if (this.localProperties != null) {for (int i = 0; i < this.localProperties.length; i++) {CollectionUtils.mergePropertiesIntoMap(this.localProperties[i], result);}}if (!this.localOverride) {// Load properties from file afterwards, to let those properties// override.loadProperties(result);}return result;}/** * Load properties into the given instance. *  * @param props *            the Properties instance to load into * @throws java.io.IOException *             in case of I/O errors * @see #setLocations */@Overrideprotected void loadProperties(Properties props) throws IOException {if (this.locations != null) {for (int i = 0; i < this.locations.length; i++) {Resource location = this.locations[i];if (logger.isInfoEnabled()) {logger.info("Loading properties file from " + location);}InputStream is = null;try {/** * 读取启动参数中的环境变量，默认为devjunit */String runEnv = System.getProperty("spring.profiles.active", "devjunit");if (location.getFilename().indexOf("." + runEnv + ".") > 0) {is = location.getInputStream();this.propertiesPersister.load(props, is);break;}} catch (IOException ex) {if (this.ignoreResourceNotFound) {if (logger.isWarnEnabled()) {logger.warn("Could not load properties from " + location + ": " + ex.getMessage());}} else {throw ex;}} finally {if (is != null) {is.close();}}}}}}

4、然后添加不同环境下的配置文件，便于减少因调整配置文件导致的失误。