Spring Boot如何读取配置呢?

SpringBoot读取配置的实现思路

方式1:
   使用value注解绑定
方式2:
   使用@ConfigurationProperties注解绑定
方式3:
   使用@PropertySource注解和
       @value注解进行绑定
方式4:
   使用@Environment注解读取配置信息

读取application文件
  在application.yml或者properties文件中添加：

	info.address=China\
	info.company=Spring\
	info.degree=high

@Value注解读取示例

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class InfoConfig1 {

    @Value("${info.address}")
    private String address;

    @Value("${info.company}")
    private String company;

    @Value("${info.degree}")
    private String degree;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getCompany() {
        return company;
    }

    public void setCompany(String company) {
        this.company = company;
    }

    public String getDegree() {
        return degree;
    }

    public void setDegree(String degree) {
        this.degree = degree;
    }

}

@ConfigurationProperties注解读取方式

@Component
@ConfigurationProperties(prefix = "info")
public class InfoConfig2 {

    private String address;
    private String company;
    private String degree;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getCompany() {
        return company;
    }

    public void setCompany(String company) {
        this.company = company;
    }

    public String getDegree() {
        return degree;
    }

    public void setDegree(String degree) {
        this.degree = degree;
    }

}

读取指定文件

资源目录下建立config/db-config.properties:

db.username=root\
db.password=123456

@PropertySource+@Value注解读取方式

@Component
@PropertySource(value = { "config/db-config.properties" })
public class DBConfig1 {

    @Value("${db.username}")
    private String username;

    @Value("${db.password}")
    private String password;

    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;
    }

}

注意事项:
   @PropertySource不支持yml文件读取

@PropertySource+@ConfigurationProperties注解读取方式

@Component
@ConfigurationProperties(prefix = "db")
@PropertySource(value = { "config/db-config.properties" })
public class DBConfig2 {

    private String username;
    private String password;

    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;
    }

}

Environment读取方式

 
@Autowired
private Environment env;

// 获取参数
String getProperty(String key);