Spring-boot参考（三）配置

约定不等于承诺〃 2022-06-04 03:29 187阅读 0赞

# debug #

开启debug开关可以查看更多的信息

java -jar myproject-0.0.1-SNAPSHOT.jar –debug  
或者  
在application.yml 中  
debug: true

# banner #

banner.txt在classpath下增加这个文件，可以替换掉启动Spring的 图案。

[Customizing the Banner][]

配置文件就是 环境变量。

# 在程序启动时 执行一些方法 #

实现 ApplicationRunner or CommandLineRunner 接口。

@Component
    public class MyBean2 implements ApplicationRunner { 
    
        @Override
        public void run(ApplicationArguments args) throws Exception {
            System.out.println(args);
        }
    }

@Component
    public class MyBean implements CommandLineRunner { 
    
        public void run(String... args) {
            // Do something...
            System.out.println("hello");
            System.out.println(args);
        }
    
    }

# 修改程序退出的 返回值 #

@SpringBootApplication
    public class ExitCodeApplication { 
    
        @Bean
        public ExitCodeGenerator exitCodeGenerator() {
            return () -> 42;
        }
    
        public static void main(String[] args) {
            System.exit(SpringApplication
                    .exit(SpringApplication.run(ExitCodeApplication.class, args)));
        }
    
    }

Spring boot 配置参数的 加载顺序

1.  Devtools global settings properties on your home directory  
    (~/.spring-boot-devtools.properties when devtools is active).
2.  @TestPropertySource annotations on your tests.
3.  @SpringBootTest\#properties annotation attribute on your tests.
4.  Command line arguments.
5.  Properties from SPRING\_APPLICATION\_JSON  
    (inline JSON embedded in an environment variable or system
6.  ServletConfig init parameters.
7.  ServletContext init parameters.
8.  JNDI attributes from java:comp/env.
9.  Java System properties (System.getProperties()).
10. OS environment variables.
11. A RandomValuePropertySource that only has properties in random.\*.
12. Profile-specific application properties outside of your packaged jar  
    (application-\{profile\}.properties and YAML variants).
13. Profile-specific application properties packaged inside your jar  
    (application-\{profile\}.properties and YAML variants).
14. Application properties outside of your packaged jar (application.properties and YAML variants).
15. Application properties packaged inside your jar  
    (application.properties and YAML variants).
16. @PropertySource  
    annotations on your @Configuration classes.
17. Default properties  
    (specified using SpringApplication.setDefaultProperties).

# 配置随机值 #

my.secret=${random.value}
    my.number=${random.int}
    my.bignumber=${random.long}
    my.uuid=${random.uuid}
    my.number.less.than.ten=${random.int(10)}
    my.number.in.range=${random.int[1024,65536]}

# 配置 SpringApplication #

public static void main(String[] args) {
        SpringApplication app = new SpringApplication(MySpringConfiguration.class);
        app.setBannerMode(Banner.Mode.OFF);
        app.run(args);
    }

# 配置文件 #

默认会从 application.properties 这个文件中读取配置

这个文件放在

*  A /config subdirectory of the current directory.
 *  The current directory
 *  A classpath /config package
 *  The classpath root  
    这几个位置都可以。

# 类型安全的 配置 ConfigurationProperties #

@Value(“$\{property\}”) 可能会造成类型的不安全， 所以提供了  
ConfigurationProperties

@ConfigurationProperties("foo")
    public class FooProperties {
    
        private boolean enabled;
    
        private InetAddress remoteAddress;
    
        private final Security security = new Security();
    
        public boolean isEnabled() { ... }
    
        public void setEnabled(boolean enabled) { ... }
    
        public InetAddress getRemoteAddress() { ... }
    
        public void setRemoteAddress(InetAddress remoteAddress) { ... }
    
        public Security getSecurity() { ... }
    
        public static class Security {
    
            private String username;
    
            private String password;
    
            private List<String> roles = new ArrayList<>(Collections.singleton("USER"));
    
            public String getUsername() { ... }
    
            public void setUsername(String username) { ... }
    
            public String getPassword() { ... }
    
            public void setPassword(String password) { ... }
    
            public List<String> getRoles() { ... }
    
            public void setRoles(List<String> roles) { ... }
    
        }
    }

ConfigurationProperties 需要设置setter方法。

# profile #

spring.profiles.active=dev,hsqldb

[Customizing the Banner]: https://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/#boot-features-banner