springboot的controller中如何获取applicatim.yml的配置值_Java

在spring boot的controller中获取application.yml配置值，主要有以下几种方式：

1. 使用@value注解（最常用）

application.yml 配置

app:
  name: "我的应用"
  version: "1.0.0"
  max-users: 100
  enabled: true
  timeout: 30000

controller 中使用

@restcontroller
@requestmapping("/api")
public class configcontroller {
    @value("${app.name}")
    private string appname;
    @value("${app.version}")
    private string appversion;
    @value("${app.max-users}")
    private int maxusers;
    @value("${app.enabled}")
    private boolean enabled;
    @value("${app.timeout}")
    private long timeout;
    @getmapping("/config")
    public map<string, object> getconfig() {
        map<string, object> config = new hashmap<>();
        config.put("name", appname);
        config.put("version", appversion);
        config.put("maxusers", maxusers);
        config.put("enabled", enabled);
        config.put("timeout", timeout);
        return config;
    }
}

2. 使用@configurationproperties（推荐用于复杂配置）

创建配置类

@configuration
@configurationproperties(prefix = "app")
@data
public class appconfig {
    private string name;
    private string version;
    private int maxusers;
    private boolean enabled;
    private long timeout;
    private list<string> whitelist;
    private map<string, string> endpoints;
}

在controller中注入使用

@restcontroller
@requestmapping("/api")
public class configcontroller {
    @autowired
    private appconfig appconfig;
    @getmapping("/config")
    public appconfig getconfig() {
        return appconfig;
    }
    @getmapping("/info")
    public string getappinfo() {
        return appconfig.getname() + " v" + appconfig.getversion();
    }
}

3. 使用environment接口

@restcontroller
@requestmapping("/api")
public class configcontroller {
    @autowired
    private environment environment;
    @getmapping("/env-config")
    public map<string, object> getenvconfig() {
        map<string, object> config = new hashmap<>();
        config.put("name", environment.getproperty("app.name"));
        config.put("version", environment.getproperty("app.version"));
        config.put("maxusers", environment.getproperty("app.max-users", integer.class));
        config.put("timeout", environment.getproperty("app.timeout", long.class, 5000l));
        return config;
    }
}

4. 复杂配置示例

application.yml

app:
  name: "用户管理系统"
  version: "2.1.0"
  database:
    url: "jdbc:mysql://localhost:3306/mydb"
    username: "admin"
    pool-size: 20
  security:
    jwt-secret: "my-secret-key"
    token-expire: 3600
    cors-origins:
      - "http://localhost:3000"
      - "https://example.com"
  features:
    enable-cache: true
    enable-notification: false

对应的配置类

@configuration
@configurationproperties(prefix = "app")
@data
public class appconfig {
    private string name;
    private string version;
    private databaseconfig database;
    private securityconfig security;
    private featuresconfig features;
    @data
    public static class databaseconfig {
        private string url;
        private string username;
        private int poolsize;
    }
    @data
    public static class securityconfig {
        private string jwtsecret;
        private int tokenexpire;
        private list<string> corsorigins;
    }
    @data
    public static class featuresconfig {
        private boolean enablecache;
        private boolean enablenotification;
    }
}

controller中使用

@restcontroller
@requestmapping("/api")
public class systemcontroller {
    @autowired
    private appconfig appconfig;
    @getmapping("/system-info")
    public map<string, object> getsysteminfo() {
        return map.of(
            "appname", appconfig.getname(),
            "databaseurl", appconfig.getdatabase().geturl(),
            "corsorigins", appconfig.getsecurity().getcorsorigins(),
            "enablecache", appconfig.getfeatures().isenablecache()
        );
    }
}

5. 带默认值的配置

@restcontroller
@requestmapping("/api")
public class configcontroller {
    // 使用默认值
    @value("${app.unknown-property:default-value}")
    private string unknownproperty;
    @value("${app.retry-count:3}")
    private int retrycount;
    @getmapping("/default-values")
    public map<string, object> getwithdefaults() {
        return map.of(
            "unknownproperty", unknownproperty,
            "retrycount", retrycount
        );
    }
}

主要区别和选择建议

方式	适用场景	优点	缺点
`@value`	简单的单个配置项	简单直接	配置分散，不易管理
`@configurationproperties`	复杂的配置组	类型安全，集中管理	需要创建配置类
`environment`	动态获取配置	灵活，可动态获取	类型转换需要手动处理