SpringBoot注入配置文件的3種方法

方案1:@ConfigurationProperties+@Component

 1 定義spring的一個實體bean裝載配置文件信息，其它要使用配置信息是注入該實體bean  2 
 3 /**
 4  * 將配置文件中配置的每個屬性的值，映射到這個組件中  5  * @ConfigurationProperties：告訴SpringBoot將本類中的全部屬性和配置文件中相關的配置進行綁定；  6  * prefix = "person"：配置文件中哪一個下面的全部屬性進行一一映射  7  *  8  * 只有這個組件是容器中的組件，才能容器提供的@ConfigurationProperties功能；  9  * 10  */
11 @Component 12 @ConfigurationProperties(prefix = "person") 13 public class Person { 14 ​ 15     private String lastName; 16     private Integer age; 17     private Boolean boss; 18     private Date birth; 19 ​ 20     private Map<String,Object> maps; 21     private List<Object> lists; 22     private Dog dog;

 

方案2：@Bean+@ConfigurationProperties

咱們還能夠把@ConfigurationProperties還能夠直接定義在@bean的註解上，這是bean實體類就不用@Component和@ConfigurationProperties了，這邊是Boot的動態數據源切換的類。

 1 package com.topcheer.oss.base.datasource;  2 ​  3 import com.alibaba.druid.pool.DruidDataSource;  4 ​  5 import com.xiaoleilu.hutool.crypto.symmetric.SymmetricAlgorithm;  6 import com.xiaoleilu.hutool.crypto.symmetric.SymmetricCrypto;  7 import com.xiaoleilu.hutool.util.CharsetUtil;  8 import com.xiaoleilu.hutool.util.HexUtil;  9 ​ 10 import lombok.extern.slf4j.Slf4j; 11 ​ 12 @Slf4j 13 public class UmspscDataSource extends DruidDataSource { 14 ​ 15     private static final long serialVersionUID = 4766401181052251539L; 16 ​ 17     private String passwordDis; 18     
19     /**
20  * 密匙 21      */
22     private final static String Pkey ="1234565437892132"; 23     
24  @Override 25     public String getPassword() { 26         if(passwordDis != null && passwordDis.length() > 0) { 27             return passwordDis; 28  } 29         String encPassword = super.getPassword(); 30         if(null == encPassword) { 31             return null; 32  } 33         log.info("數據庫密碼加解密，{" + encPassword + "}"); 34         try { 35             // 密文解密，解密方法能夠修改
36             String key = HexUtil.encodeHexStr(Pkey); 37             SymmetricCrypto aes = new SymmetricCrypto(SymmetricAlgorithm.AES, key.getBytes()); 38             passwordDis = aes.decryptStr(encPassword, CharsetUtil.CHARSET_UTF_8); 39             return passwordDis; 40         } catch (Exception e) { 41             log.error("數據庫密碼解密出錯，{"+encPassword + "}"); 42             //log.error(LogUtil.e(e)); 43             //throw new Exception("數據庫密碼解密失敗！", e);
44             return null; 45  } 46  } 47 ​ 48 }

 

 1 @Bean(name = "systemDataSource")  2     @ConfigurationProperties(ignoreUnknownFields = false, prefix = "spring.datasource.system")  3     public DataSource systemDataSource() {  4         return new UmspscDataSource();  5  }  6 ​  7     @Bean(name = "secondDataSource")  8     @ConfigurationProperties(ignoreUnknownFields = false, prefix = "spring.datasource.second")  9     public DataSource secondDataSource() { 10         return new UmspscDataSource(); 11  } 12     
13     @Bean(name="systemJdbcTemplate") 14     public JdbcTemplate systemJdbcTemplate( 15             @Qualifier("systemDataSource") DataSource dataSource) { 16         return new JdbcTemplate(dataSource); 17  } 18     
19     @Bean(name="secondJdbcTemplate") 20     public JdbcTemplate secondJdbcTemplate( 21             @Qualifier("secondDataSource") DataSource dataSource) { 22         return new JdbcTemplate(dataSource); 23     }

 

​

 

方案3:@ConfigurationProperties + @EnableConfigurationProperties

咱們和上面例子同樣註解屬性，而後用 Spring的@Autowire來注入 mail configuration bean:

 1 package com.dxz.property;  2 ​  3 import org.springframework.boot.context.properties.ConfigurationProperties;  4 ​  5 @ConfigurationProperties(locations = "classpath:mail.properties", ignoreUnknownFields = false, prefix = "mail")  6 public class MailProperties {  7     private String host;  8     private int port;  9     private String from; 10     private String username; 11     private String password; 12     private Smtp smtp; 13 ​ 14     // ... getters and setters
15     public String getHost() { 16         return host; 17  } 18 ​ 19     public void setHost(String host) { 20         this.host = host; 21  } 22 ​ 23     public int getPort() { 24         return port; 25  } 26 ​ 27     public void setPort(int port) { 28         this.port = port; 29  } 30 ​ 31     public String getFrom() { 32         return from; 33  } 34 ​ 35     public void setFrom(String from) { 36         this.from = from; 37  } 38 ​ 39     public String getUsername() { 40         return username; 41  } 42 ​ 43     public void setUsername(String username) { 44         this.username = username; 45  } 46 ​ 47     public String getPassword() { 48         return password; 49  } 50 ​ 51     public void setPassword(String password) { 52         this.password = password; 53  } 54 ​ 55     public Smtp getSmtp() { 56         return smtp; 57  } 58 ​ 59     public void setSmtp(Smtp smtp) { 60         this.smtp = smtp; 61  } 62     
63  @Override 64     public String toString() { 65         return "MailProperties [host=" + host + ", port=" + port + ", from=" + from + ", username=" + username 66                 + ", password=" + password + ", smtp=" + smtp + "]"; 67  } 68 ​ 69     public static class Smtp { 70         private boolean auth; 71         private boolean starttlsEnable; 72 ​ 73         public boolean isAuth() { 74             return auth; 75  } 76 ​ 77         public void setAuth(boolean auth) { 78             this.auth = auth; 79  } 80 ​ 81         public boolean isStarttlsEnable() { 82             return starttlsEnable; 83  } 84 ​ 85         public void setStarttlsEnable(boolean starttlsEnable) { 86             this.starttlsEnable = starttlsEnable; 87  } 88 ​ 89  } 90 }

 

啓動類及測試類：

 1 package com.dxz.property;  2 ​  3 import org.springframework.beans.factory.annotation.Autowired;  4 import org.springframework.boot.autoconfigure.SpringBootApplication;  5 import org.springframework.boot.builder.SpringApplicationBuilder;  6 import org.springframework.boot.context.properties.EnableConfigurationProperties;  7 import org.springframework.web.bind.annotation.RequestMapping;  8 import org.springframework.web.bind.annotation.RequestMethod;  9 import org.springframework.web.bind.annotation.ResponseBody; 10 import org.springframework.web.bind.annotation.RestController; 11 ​ 12 @RestController 13 @SpringBootApplication 14 @EnableConfigurationProperties(MailProperties.class) 15 public class TestProperty1 { 16 ​ 17  @Autowired 18     private MailProperties mailProperties; 19     
20     @RequestMapping(value = "/hello", method = RequestMethod.GET) 21  @ResponseBody 22     public String hello() { 23         System.out.println("mailProperties" + mailProperties); 24         return "hello world"; 25  } 26 ​ 27     public static void main(String[] args) { 28         //SpringApplication.run(TestProperty1.class, args);
29         new SpringApplicationBuilder(TestProperty1.class).web(true).run(args); 30 ​ 31  } 32 }

 

結果：

請注意@EnableConfigurationProperties註解。該註解是用來開啓對@ConfigurationProperties註解配置Bean的支持。也就是@EnableConfigurationProperties註解告訴Spring Boot 能支持@ConfigurationProperties。若是不指定會看到以下異常:

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.dxz.property.MailProperties] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

注意: 還有其餘辦法 (Spring Boot 老是有其餘辦法!) 讓@ConfigurationProperties beans 被添加 – 用@Configuration或者 @Component註解, 這樣就能夠在 component scan時候被發現了。

	@ConfigurationProperties	@Value
功能	批量注入配置文件中的屬性	一個個指定
鬆散綁定（鬆散語法）	支持	不支持
SpEL	不支持	支持
JSR303數據校驗	支持	不支持
複雜類型封裝	支持	不支持

配置文件yml仍是properties他們都能獲取到值；

若是說，咱們只是在某個業務邏輯中須要獲取一下配置文件中的某項值，使用@Value；

若是說，咱們專門編寫了一個javaBean來和配置文件進行映射，咱們就直接使用@ConfigurationProperties；