springboot多环境配置文件及自定义配置文件路径详解

一：什么是classpath？

classpath指的就是 *.java文件，资源文件等编译后存放的位置，对于maven项目就是指 target/classes:这个路径，只要编译后的文件在这个目录下，springboot就可以找到，这里指的是maven项目，javaWeb项目可能会有区别。

二、自定义springboot配置文件路径

springboot项目配置文件application.properties或者application.yml配置文件默认放置的位置是 **“classpath:/,classpath:/config/,file:./,file:./config/ ”**这4个位置。只要我们编译后的文件位于这4个位置，springboot就可以加载配置文件。

但有时候我们需要以环境名称为标识，配置多个环境的配置文件。如下我们需要配置dev1、dev2、stg1、stg2、prd 共5个环境，每个环境下分别配置我们的application.properties，数据库配置，redis配置，日志配置等配置。

这时我们的资源文件的路径已经不再是springboot默认的配置路径了，因此springboot启动时将无法加载配置文件，这里就需要我们在启动类中手动指定配置文件的加载路径了。如下：

public class DemoApplication  {
   public static void main(String[] args) {
        //springboot默认的配置文件路径
       // String addClassPath = "spring.config.location:classpath:/";
        //自定义的配置文件路径
       String addClassPath = "spring.config.additional-location:classpath:/";
       addClassPath += ",classpath:/config/";
       addClassPath += ",classpath:/config/dev1/";
       addClassPath += ",classpath:/config/dev2/";
       addClassPath += ",classpath:/config/stg1/";
       addClassPath += ",classpath:/config/stg2/";
       addClassPath += ",classpath:/config/prd/";
       new SpringApplicationBuilder(DemoApplication.class).properties("spring.config.name:application", addClassPath).build().run(args);
   }

springboot的加载配置项在ConfigFileApplicationListener类中，可以自行翻看下源码定义。如下是我们从spring源码中复制过来的一分部，可以发现一些我们熟悉默认配置定义，如spring.profiles.active、classpath:/,classpath:/config/,file:./,file:./config/、spring.config.name等。

public class ConfigFileApplicationListener
implements EnvironmentPostProcessor, SmartApplicationListener, Ordered {

private static final String DEFAULT_PROPERTIES = "defaultProperties";

// Note the order is from least to most specific (last one wins)
private static final String DEFAULT_SEARCH_LOCATIONS = "classpath:/,classpath:/config/,file:./,file:./config/";

private static final String DEFAULT_NAMES = "application";

private static final Set<String> NO_SEARCH_NAMES = Collections.singleton(null);

/**
* The "active profiles" property name.
*/
public static final String ACTIVE_PROFILES_PROPERTY = "spring.profiles.active";

/**
* The "includes profiles" property name.
*/
public static final String INCLUDE_PROFILES_PROPERTY = "spring.profiles.include";

/**
* The "config name" property name.
*/
public static final String CONFIG_NAME_PROPERTY = "spring.config.name";

/**
* The "config location" property name.
*/
public static final String CONFIG_LOCATION_PROPERTY = "spring.config.location";

/**
* The "config additional location" property name.
*/
public static final String CONFIG_ADDITIONAL_LOCATION_PROPERTY = "spring.config.additional-location";

/**
* The default order for the processor.
*/
public static final int DEFAULT_ORDER = Ordered.HIGHEST_PRECEDENCE + 10;

/**
* Name of the application configuration {@link PropertySource}.
*/
@Deprecated
public static final String APPLICATION_CONFIGURATION_PROPERTY_SOURCE_NAME = "applicationConfigurationProperties";

private final DeferredLog logger = new DeferredLog();

private String searchLocations;

private String names;

private int order = DEFAULT_ORDER;
     。。。。。。。。。（略）

来源：https://blog.csdn.net/m0_37735176/article/details/89085843