Spring配置类-使用ConfigurationProperties 动态获取配置文件信息

使用场景: 有时候需要再配置类Configuration中动态获取配置文件properties中的自定义值

原始方法:使用ClassLoader读取

缺点: 该方式只能读取类路径下的配置文件

**案例:**创建一个自定义参数的线程池,参数从配置文件中获取

@Configuration public class MyThreadConfig { @Bean public ThreadPoolExecutor threadPool(){ Properties properties = new Properties(); // 使用ClassLoader加载properties配置文件生成对应的输入流 InputStream in = MyThreadConfig.class.getClassLoader().getResourceAsStream("config.properties"); // 使用properties对象加载输入流 try { properties.load(in); return new ThreadPoolExecutor(new Integer(properties.getProperty("coreSize")), new Integer(properties.getProperty("maxSize")), new Long(properties.getProperty("keepAliveTime")), TimeUnit.SECONDS, new LinkedBlockingDeque<>(100000), Executors.defaultThreadFactory(), new ThreadPoolExecutor.AbortPolicy()); } catch (IOException e) { e.printStackTrace(); } return null; } }

使用ConfigurationProperties

导入辅助依赖

这个依赖会只会产生编码时提示,不导入也可以

<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-configuration-processor</artifactId> </dependency>

编写配置参数类ThreadPoolConfigPorperties

使用@ConfigurationProperties绑定application.properties中的自定义配置prefix 前缀定义了哪些外部属性将绑定到类的字段@Component 将对象添加进spring容器,方便Config类使用类的字段必须有公共 setter 方法 //绑定配置文件中与gulimail.thread 有关的配置 @ConfigurationProperties(prefix ="gulimail.thread" ) @Component @Data public class ThreadPoolConfigProperties { private Integer coreSize; private Integer maxSize; private Integer keepAliveTime; }

编写配置类MyThreadConfig

使用ThreadPoolConfigProperties 作为方法参数,Spring会自动依赖注入对象调用get方法取值 @Configuration public class MyThreadConfig { @Bean public ThreadPoolExecutor threadPoolExecutor(ThreadPoolConfigProperties properties){ return new ThreadPoolExecutor(properties.getCoreSize(), properties.getMaxSize(), properties.getKeepAliveTime(), TimeUnit.SECONDS, new LinkedBlockingDeque<>(100000), Executors.defaultThreadFactory(), new ThreadPoolExecutor.AbortPolicy()); } }