Spring基于注解读取外部配置文件

/**
 * 使用@PropertySource指定具体的配置文件，用@Value设置具体的属性值， 不支持yml
 */
@Component
@PropertySource("classpath:config.properties")
public class DbProperties {

  @Value("${ps.datasource.driverClassName}")
  private String driverClassName;
  @Value("${ps.datasource.jdbcUrl}")
  private String jdbcUrl;
  @Value("${ps.datasource.username}")
  private String username;
  @Value("${ps.datasource.password}")
  private String password;
  @Value("${ps.datasource.minIdle}")
  private int minIdle;
  @Value("${ps.datasource.maxPoolSize}")
  private int maxPoolSize;
  @Value("${ps.datasource.connectionTimeout}")
  private int connectionTimeout;
  @Value("${ps.datasource.idleTimeout}")
  private int idleTimeout;

  public String getDriverClassName() {
    return driverClassName;
  }

  public void setDriverClassName(String driverClassName) {
    this.driverClassName = driverClassName;
  }

  public String getJdbcUrl() {
    return jdbcUrl;
  }

  public void setJdbcUrl(String jdbcUrl) {
    this.jdbcUrl = jdbcUrl;
  }

  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;
  }

  public int getMinIdle() {
    return minIdle;
  }

  public void setMinIdle(int minIdle) {
    this.minIdle = minIdle;
  }

  public int getMaxPoolSize() {
    return maxPoolSize;
  }

  public void setMaxPoolSize(int maxPoolSize) {
    this.maxPoolSize = maxPoolSize;
  }

  public int getConnectionTimeout() {
    return connectionTimeout;
  }

  public void setConnectionTimeout(int connectionTimeout) {
    this.connectionTimeout = connectionTimeout;
  }

  public int getIdleTimeout() {
    return idleTimeout;
  }

  public void setIdleTimeout(int idleTimeout) {
    this.idleTimeout = idleTimeout;
  }

  @Override
  public String toString() {
    return "DbProperties{" +
        "driverClassName='" + driverClassName + '\'' +
        ", jdbcUrl='" + jdbcUrl + '\'' +
        ", username='" + username + '\'' +
        ", password='" + password + '\'' +
        ", minIdle=" + minIdle +
        ", maxPoolSize=" + maxPoolSize +
        ", connectionTimeout=" + connectionTimeout +
        ", idleTimeout=" + idleTimeout +
        '}';
  }
}

/**
 * Environment可以获取classpath下配置的属性值，无需指定具体的配置文件。 不支持yml
 */
@Component
public class UserProperties {

  @Autowired
  private Environment env;

  public String getUserName() {
    return env.getProperty("user.name");
  }

  public String getPassword() {
    return env.getProperty("user.password");
  }
}

try {
      Properties properties = PropertiesLoaderUtils.loadAllProperties("config.properties");
      System.out.println(properties.getProperty("user.name"));
    } catch (IOException e) {
      e.printStackTrace();
    }