SpringBoot2.X 项目使用外置绝对路径的配置文件

spring-boot-absolute-config

前言

　　该工程是为解决应用部署应用时指定配置文件存放位置的问题.

　　SpringBoot项目默认加载以下位置的配置文件:

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classpath: file:./ classpath:config/ file:./config/:

　　想要指定外部的配置文件, 一种方法就是通过启动脚本来控制:

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1 2	在启动脚本中添加: -Dspring.config.location=文件绝对路径

但有时候有些项目需要兼容之前的老项目,就会遇到使用外部绝对路径的来指定配置文件了,每次都在启动脚本中添加,显然不是很合适.因此诞生了该工程.

实现方式

通过实现 EnvironmentPostProcessor 接口, 自定义实现方法:

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1	public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application)

来实现加载自定义配置文件.

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package com.github.springboot.absolute.config;   import org.springframework.boot.SpringApplication; import org.springframework.boot.context.config.ConfigFileApplicationListener; import org.springframework.boot.env.EnvironmentPostProcessor; import org.springframework.boot.env.PropertiesPropertySourceLoader; import org.springframework.boot.env.PropertySourceLoader; import org.springframework.boot.env.YamlPropertySourceLoader; import org.springframework.core.Ordered; import org.springframework.core.env.ConfigurableEnvironment; import org.springframework.core.env.PropertySource; import org.springframework.core.io.PathResource; import org.springframework.core.io.Resource; import org.springframework.util.StringUtils;   import java.io.FileNotFoundException; import java.io.IOException; import java.util.List;   /**  * <p> 自定义环境加载策略  * <p>需要在classpath下application.yml或application.properties中指定文件位置</p>  * <p>key=config.file.absolute.path</p>  *  * @author lijinghao  * @version : MyEnvironmentPostProcessor.java, v 0.1 2018年09月13日 下午4:55:55 lijinghao Exp $  */ public class MyEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered {       /**,      * 指定加载外部文件类型: [.properties], [.yml], [.yaml]      */     private static final String SUFFIX_TYPE_YML                             = ".yml";     private static final String SUFFIX_TYPE_YAML                            = ".yaml";     private static final String SUFFIX_TYPE_PROPERTIES                      = ".properties";       /**      * 指定外部配置文件路径的KEY      */     private static final String CONFIG_FILE_ABSOLUTE_PATH                   = "config.file.absolute.path";       private static final int DEFAULT_ORDER                                  = ConfigFileApplicationListener.DEFAULT_ORDER + 1;       /**      * Post-process the given {@code env}.      *      * @param environment the env to post-process      * @param application the application to which the env belongs      */     @Override     public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {           try {               // Get file absolute path             String path = environment.getProperty(CONFIG_FILE_ABSOLUTE_PATH);             if (StringUtils.isEmpty(path)) {                 System.out.println("WARNING: External file path to be loaded is not configured.[config.file.absolute.path]");                 return;             }               System.out.println("INFO: Loading external file: \"" + path + "\"");               // Loading external file             Resource resource = new PathResource(path);               PropertySourceLoader loader;               if (resource.exists() && resource.isFile()) {                 String filename = resource.getFilename();                 String fileSuffix = filename.substring(filename.indexOf("."));                   if (SUFFIX_TYPE_PROPERTIES.equalsIgnoreCase(fileSuffix)) {                     loader = new PropertiesPropertySourceLoader();                   } else if (SUFFIX_TYPE_YML.equalsIgnoreCase(fileSuffix)                         || SUFFIX_TYPE_YAML.equalsIgnoreCase(fileSuffix)) {                     loader = new YamlPropertySourceLoader();                   } else {                     throw new RuntimeException("Unsupported file types: " + fileSuffix);                 }             }else {                 throw new FileNotFoundException("Cannot find the file : \"" + path +"\"");             }               List<PropertySource<?>> sources = loader.load("externalFiles", resource);             for (PropertySource<?> source : sources) {                 environment.getPropertySources().addLast(source);             }         } catch (IOException e) {             e.printStackTrace();         }       }         /**      * Get the order value of this object.      * <p>Higher values are interpreted as lower priority. As a consequence,      * the object with the lowest value has the highest priority (somewhat      * analogous to Servlet {@code load-on-startup} values).      * <p>Same order values will result in arbitrary sort positions for the      * affected objects.      *      * @return the order value      * @see #HIGHEST_PRECEDENCE      * @see #LOWEST_PRECEDENCE      */     @Override     public int getOrder() {         return DEFAULT_ORDER;     }   }

　　在classpath:META-INF 下创建：spring.factories

　　添加如下内容：

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1	org.springframework.boot.env.EnvironmentPostProcessor=com.github.springboot.absolute.config.MyEnvironmentPostProcessor

使用说明

1. 引入pom文件

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   <dependency>      <groupId>com.github.springboot</groupId>     <artifactId>absolute-config</artifactId>     <version>1.0.0-RELEASE</version>  </dependency>

2. 在classpath下的配置文件中增加参数

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   1 2	如,在application.yml中添加 config.file.absolute.path: /opt/app/config/**/**/application.yml

3. 重启项目

   重启项目时,会自动加载指定位置的配置文件;

注意事项

1. 支持配置文件的格式

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   1 2	1) classpath下SpringBoot默认加载application.properties、application.yml或application.yaml; 2) 外置配置文件可以是以.properties、.yml或.yaml结尾（注意配置内容的格式）；

2. 外部加载的配置文件,不能使用原始配置文件的key

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   1 2	如: server.port: 8090  此参数只在classpath下的配置文件中生效,在外部加载的配置文件中不生效.

   此类key主要是在 ConfigFileApplicationListener 中进行加载.

3. 引入了配置文件,但没配置config.file.absolute.path

   此时不会报错,只会在启动时打印提醒的语句.

4. 配置了错误的config.file.absolute.path

   此时在项目启动时会打印出错误的异常栈,但不影响程序的正常启动.

   但是,如果你的项目中依赖了外置配置文件中的内容,可能会报错.

　　具体源代码详见：https://github.com/lthaoshao/spring-boot-absolute-config

原文地址：https://www.cnblogs.com/lthaoshao/p/9676045.html