springboot属性注入方式,读取配置

读取指定文件

@PropertySource(value = "classpath:qinjiang.properties")

1

application.properties

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/springboot_test
jdbc.username=root
jdbc.password=root

JdbcProperties.java

package com.itheima.config;

import org.springframework.boot.context.properties.ConfigurationProperties;
/*
*ConfigurationProperties 从application配置文件中读取配置项
*prefix 表示配置项的前缀
* 配置项类中的类变量名必须要与 前缀之后的配置项名称保存 松散绑定(相同)
* */

@ConfigurationProperties( prefix = "jdbc")
public class JdbcProperties {
    private String url;
    private String driverClassName;
    private String username;
    private String password;

    public String getDriverClassName() {
        return driverClassName;
    }

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

    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 String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }
}

JdbcConfigSpringBoot.java

package com.itheima.config;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
@Configuration
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfigSpringBoot {
    @Bean
    public DataSource dataSource(JdbcProperties jdbcProperties){
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(jdbcProperties.getDriverClassName());
        dataSource.setUrl(jdbcProperties.getUrl());
        dataSource.setUsername(jdbcProperties.getUsername());
        dataSource.setPassword(jdbcProperties.getPassword());
        return dataSource;
    }
}

 2

application.properties

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/springboot_test
jdbc.username=root
jdbc.password=root

JdbcConfigSpringBoot.java

package com.itheima.config;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
@Configuration
public class JdbcConfigSpringBoot {
    @Bean
    @ConfigurationProperties(prefix = "jdbc")
    public DataSource dataSource(){
        return new DruidDataSource();
    }
}