Spring Boot 外部化配置总结

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Externalized Configuration

更多信息参考：7.2 Externalized Configuration

Spring Boot lets you externalize your configuration so that you can work with the same application code in different environments. You can use a variety of external configuration sources, include Java properties files, YAML files, environment variables, and command-line arguments.

Property values can be injected directly into your beans by

  • using the @Value annotation, accessed through Spring’s Environment abstraction,
  • or be bound to structured objects through @ConfigurationProperties.

Spring Boot uses a very particular PropertySource order that is designed to allow sensible overriding of values. Later property sources can override the values defined in earlier ones. Sources are considered in the following order:

  1. Default properties (specified by setting SpringApplication.setDefaultProperties).
  2. @PropertySource annotations on your @Configuration classes.
  3. ⭐️ Config data (such as application.properties files).
  4. A RandomValuePropertySource that has properties only in random.*.
  5. ⭐️ OS environment variables (System.getenv()).
  6. ⭐️ Java System properties (System.getProperties()) (that is, arguments starting with -D, such as -Dspring.profiles.active=prod).
  7. ⭐️ JNDI attributes from java:comp/env.
  8. ServletContext init parameters.
  9. ServletConfig init parameters.
  10. Properties from SPRING_APPLICATION_JSON (inline JSON embedded in an environment variable or system property).
  11. ⭐️ Command line arguments. (that is, arguments starting with --, such as --server.port=9000)
  12. properties attribute on your tests. Available on @SpringBootTest and the test annotations for testing a particular slice of your application.
  13. @TestPropertySource annotations on your tests.
  14. Devtools global settings properties in the $HOME/.config/spring-boot directory when devtools is active.

⭐️ Config data files are considered in the following order:

  1. Application properties packaged inside your jar (application.properties and YAML variants).
  2. Profile-specific application properties packaged inside your jar (application-{profile}.properties and YAML variants).
  3. Application properties outside of your packaged jar (application.properties and YAML variants).
  4. Profile-specific application properties outside of your packaged jar (application-{profile}.properties and YAML variants).

It is recommended to stick with one format for your entire application. If you have configuration files with both .properties and .yml format in the same location, .properties takes precedence.

External Application Properties

7.2.3. External Application Properties

Spring Boot will automatically find and load application.properties and application.yaml files from the following locations when your application starts:

  1. From the classpath
    1. The classpath root
    2. The classpath /config package
  2. From the current directory
    1. The current directory
    2. The config/ subdirectory in the current directory
    3. Immediate child directories of the config/ subdirectory

The list is ordered by precedence (with values from lower items overriding earlier ones). Documents from the loaded files are added as PropertySources to the Spring Environment.

spring.config.name 修改配置文件名称：

If you do not like application as the configuration file name, you can switch to another file name by specifying a spring.config.name environment property.

For example, to look for myproject.properties and myproject.yaml files you can run your application as follows:

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$ java -jar myproject.jar --spring.config.name=myproject

spring.config.location 引用外部配置文件：

You can also refer to an explicit location by using the spring.config.location environment property. This property accepts a comma-separated list of one or more locations to check.

The following example shows how to specify two distinct files:

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$ java -jar myproject.jar --spring.config.location=\
 optional:classpath:/default.properties,\
 optional:classpath:/override.properties

Use the prefix optional: if the locations are optional and you do not mind if they do not exist.

配置嵌入式服务器

Spring Boot 集成了 Tomcat、Jetty 和 Undertow，极大便利了项目部署。下面介绍一些常用配置：

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server.port=8080 # Server HTTP port.
server.context-path= # Context path

Tomcat

URI 编码配置：

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server.tomcat.uri-encoding=UTF-8 # Character encoding to use to decode the URI.

代理配置：

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server.tomcat.remote-ip-header= # Name of the http header from which the remote ip is extracted. For instance `X-FORWARDED-FOR`
server.tomcat.protocol-header= # Header that holds the incoming protocol, usually named "X-Forwarded-Proto".
server.tomcat.port-header=X-Forwarded-Port # Name of the HTTP header used to override the original port value.

Socket 连接限制及等待超时时间：

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server.tomcat.max-connections= # Maximum number of connections that the server will accept and process at any given time.
server.connection-timeout= # Time in milliseconds that connectors will wait for another HTTP request before closing the connection. When not set, the connector's container-specific default will be used. Use a value of -1 to indicate no (i.e. infinite) timeout.

业务线程池调优：

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server.tomcat.max-threads=0 # Maximum amount of worker threads. Default 200.
server.tomcat.min-spare-threads=0 # Minimum amount of worker threads.
server.tomcat.accept-count= # Maximum queue length for incoming connection requests when all possible request processing threads are in use.

Undertow

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# 设置IO线程数, 它主要执行非阻塞的任务,它们会负责多个连接, 默认设置每个CPU核心一个线程
# 不要设置过大，如果过大，启动项目会报错：打开文件数过多
server.undertow.io-threads=16

# 阻塞任务线程池, 当执行类似servlet请求阻塞IO操作, undertow会从这个线程池中取得线程
# 它的值设置取决于系统线程执行任务的阻塞系数，默认值是IO线程数*8
server.undertow.worker-threads=256

# 以下的配置会影响buffer,这些buffer会用于服务器连接的IO操作,有点类似netty的池化内存管理
# 每块buffer的空间大小,越小的空间被利用越充分，不要设置太大，以免影响其他应用，合适即可
server.undertow.buffer-size=1024

# 每个区分配的buffer数量 , 所以pool的大小是buffer-size * buffers-per-region
server.undertow.buffers-per-region=1024

# 是否分配的直接内存(NIO直接分配的堆外内存)
server.undertow.direct-buffers=true

https://www.cnblogs.com/duanxz/p/9337022.html

属性注入

Common Application Properties

Appendix A: Common Application Properties

参考

《Spring Boot in Action》

Spring Boot Tomcat 配置