@PropertySource配置的用法

目录

功能：

用法一：@PropertySource + @Value

用法二：@PropertySource 和 @ConfigurationProperties

用法三：@ConfigurationProperties + application.yml

---

功能：

• 加载指定的属性文件（*.properties）到 Spring 的 Environment 中。可以配合 @Value 和                                                    @ConfigurationProperties 使用。
• @PropertySource 和 @Value组合使用，可以将自定义属性文件中的属性变量值注入到当前类的使用@Value注解的成员变量中。
• @PropertySource 和 @ConfigurationProperties组合使用，可以将属性文件与一个Java类绑   定，将属性文件中的变量值注入到该Java类的成员变量中。

源码

package org.springframework.context.annotation;
 
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
 
import org.springframework.core.io.support.PropertySourceFactory;
 
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Repeatable(PropertySources.class)
public @interface PropertySource {
 
    /**
     * 属性源的名称
     */
    String name() default "";
 
    /**
     * 属性文件的存放路径
     */
    String[] value();
 
    /**
     * 如果指定的属性源不存在，是否要忽略这个错误
     */
    boolean ignoreResourceNotFound() default false;
 
    /**
     * 属性源的编码格式
     */
    String encoding() default "";
 
    /**
     * 属性源工厂
     */
    Class<? extends PropertySourceFactory> factory() default PropertySourceFactory.class;
 
}

用法一：@PropertySource + @Value

属性文件：jdbc.properties

jdbc.driverClassName=jdbc.mysql
jdbc.url=mysql:jdbc://localhost:3306/ssm_db
jdbc.username=root
jdbc.password=123

 
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;
 
 
@Component
@PropertySource(value = {"classpath:jdbc.properties"})
public class JdbcProperty {
 
    private String driverClassName;
    private String url;
    private String username;
    private String password;
 
 
    public String getDriverClassName() {
        return driverClassName;
    }
 
    public void setDriverClassName(String driverClassName) {
        this.driverClassName = driverClassName;
    }
 
    public String getUrl() {
        return url;
    }
 
    public void setUrl(String url) {
        this.url = url;
    }
 
    public String getUsername() {
        return username;
    }
 
    public void setUsername(String username) {
        this.username = username;
    }
 
    public String getPassword() {
        return password;
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
 
    @Override
    public String toString() {
        return "JdbcProperty{" +
                "driverClassName='" + driverClassName + '\'' +
                ", url='" + url + '\'' +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

用法二：@PropertySource 和 @ConfigurationProperties

 
@Component
@PropertySource(value = {"classpath:jdbc.properties"})
@ConfigurationProperties(prefix = "jdbc")
public class JdbcProperty {
 
    private String driverClassName;
    private String url;
    private String username;
    private String password;
 
 
    public String getDriverClassName() {
        return driverClassName;
    }
 
    public void setDriverClassName(String driverClassName) {
        this.driverClassName = driverClassName;
    }
 
    public String getUrl() {
        return url;
    }
 
    public void setUrl(String url) {
        this.url = url;
    }
 
    public String getUsername() {
        return username;
    }
 
    public void setUsername(String username) {
        this.username = username;
    }
 
    public String getPassword() {
        return password;
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
 
    @Override
    public String toString() {
        return "JdbcProperty{" +
                "driverClassName='" + driverClassName + '\'' +
                ", url='" + url + '\'' +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }

测试案例：

@RestController
public class UserController {
 
    @Autowired
    private UserService userService;
    @Autowired
    JdbcProperty jdbcProperty;
 
    @PostMapping("/save")
    public String save(@RequestParam Map<String, Object> userMap){
        System.out.println(jdbcProperty.toString());
 
//        userService.save(userMap);
        return "save success";
    }
}

测试结果：

JdbcProperty{driverClassName='jdbc.mysql', url='mysql:jdbc://localhost:3306/ssm_db', username='root', password='123'}

用法三：@ConfigurationProperties + application.yml

DbConfig.java

@Configuration
public class DBConfig {
 
    @Bean
    @ConfigurationProperties(prefix = "jdbc")
    public DataSource dataSource(){
        return new DruidDataSource();
    }
 
    @Bean
    public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource){
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dataSource);
        return factoryBean;
    }
 
}

application.yml

server:
  port: 1111
jdbc:
  driverClassName: jdbc.mysql
  url: mysql:jdbc://localhost:3306/ssm_db
  username: root
  password: 123

测试案例：