项目在运行过程中，动态更新数据库url,username,password，实现可以通过druid连接池的restart()方法实现，配置数据源保存在服务器本地用户目录下
准备
CREATE DATABASE `test1`;
CREATE TABLE `user` (
`id` bigint NOT NULL AUTO_INCREMENT,
`username` varchar(100) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4;
INSERT INTO test2.`user` (id, username) VALUES(1, 'zhangsan');
CREATE DATABASE `test1`;
CREATE TABLE `user` (
`id` bigint NOT NULL AUTO_INCREMENT,
`username` varchar(100) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4;
INSERT INTO test2.`user` (id, username) VALUES(1, 'lisi');
1.依赖
implementation 'org.springframework.boot:spring-boot-starter-web'
compileOnly 'org.projectlombok:lombok'
runtimeOnly 'mysql:mysql-connector-java'
annotationProcessor 'org.projectlombok:lombok'
implementation 'com.baomidou:mybatis-plus-boot-starter:3.5.2'
implementation 'com.alibaba:druid-spring-boot-starter:1.1.10'
2.yaml配置
主要是配置mybatis，url只是为了站位，不然要启动要报错
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://{IP}:{port}/{database}
username: root
password: root
mybatis-plus:
mapper-locations: classpath*:/mapper/**/*.xml
configuration:
map-underscore-to-camel-case: true
3.数据源配置
package app.config;
import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import javax.sql.DataSource;
@Configuration
public class DataSourceConfiguration {
@Primary
@Bean(name = "dataSource")
@ConfigurationProperties("spring.datasource")
public DataSource dataSource() {
return new DruidDataSourceBuilder().build();
}
}
4.启动类
package app;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
public class SpringBootCustomDynamicApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootCustomDynamicApplication.class, args);
}
}
5.工具类
- DataSourceUtils
package app.utils;
import com.alibaba.druid.pool.DruidAbstractDataSource;
import com.alibaba.druid.pool.DruidDataSource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.sql.SQLException;
import java.util.Properties;
/**
* 更新数据源
*/
@Slf4j
public class DataSourceUtils {
/**
* 将数据库配置文件存放到用户目录下
*/
public static String PATH = System.getProperty("user.home") + "/db-default.properties";
/**
* 刷新数据源
*
* @return
* @throws SQLException
*/
public static String refresh(String path) throws SQLException, IOException {
Properties prop = new Properties();
try (InputStream is = Files.newInputStream(Paths.get(path))) {
prop.load(is);
String username = prop.getProperty("username");
String password = prop.getProperty("password");
String url = prop.getProperty("url");
String driverClassName = prop.getProperty("driverClassName");
if (StringUtils.hasText(username) || StringUtils.hasText(url) || StringUtils.hasText(password) || StringUtils.hasText(driverClassName)) {
DruidDataSource master = (DruidDataSource) SpringUtils.getBean("dataSource");
if (StringUtils.hasText(username)) {
master.setUsername(username);
}
if (StringUtils.hasText(password)) {
master.setPassword(password);
}
if (StringUtils.hasText(url)) {
//com.alibaba.druid.pool.DruidAbstractDataSource.inited为true时报错，导致无法修改url
//这里先调用一次restart()方法将inited重置为false，再setUrl()
master.restart();
master.setUrl(url);
}
if (StringUtils.hasText(driverClassName)) {
master.setDriverClassName(driverClassName);
}
master.restart();
log.info("mysql: {}", url);
}
return "success";
}
}
}
- SpringUtils
package app.utils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
@Slf4j
@Component
public class SpringUtils implements ApplicationContextAware {
private static ApplicationContext context;
@Override
public void setApplicationContext(ApplicationContext context) throws BeansException {
SpringUtils.context = context;
}
public static <T> T getBean(Class<T> clazz) {
return context.getBean(clazz);
}
public static Object getBean(String beanName) {
return context.getBean(beanName);
}
/**
* 重启加载之前保存的配置文件配置的数据库信息
*/
@PostConstruct
void init() {
try {
DataSourceUtils.refresh(DataSourceUtils.PATH);
} catch (Exception e) {
log.error("数据源加载失败", e);
}
}
}
5.实体类
- User
package app.domain.entity;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.Data;
@Data
public class User {
@TableId(type = IdType.AUTO)
private Long id;
private String username;
}
- DataSourceRequestVO
package app.domain.vo;
import lombok.Data;
@Data
public class DataSourceRequestVO {
private String url;
private String username;
private String password;
private String driverClassName;
}
7.Mapper
- UserMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="app.mapper.UserMapper">
<!--查询所有用户信息-->
<select id="list" resultType="app.domain.entity.User">
select * from user
</select>
</mapper>
- UserMapper.java
package app.mapper;
import app.domain.entity.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
@Mapper
public interface UserMapper extends BaseMapper<User> {
List<User> list();
}
8.数据源更新接口
package app.controller;
import app.domain.vo.DataSourceRequestVO;
import app.utils.DataSourceUtils;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.sql.SQLException;
import java.util.Optional;
import java.util.Properties;
@Slf4j
@RestController
public class DataSourceController {
/**
* 刷新数据源
* https://icode.best/i/00350443878337
*
* @return
* @throws SQLException
*/
@SneakyThrows
@PostMapping("/db/save")
public Object save(@RequestBody DataSourceRequestVO vo) {
if (vo != null) {
Properties prop = new Properties();
if (StringUtils.hasText(vo.getUsername()) || StringUtils.hasText(vo.getUrl()) || StringUtils.hasText(vo.getPassword()) || StringUtils.hasText(vo.getDriverClassName())) {
if (StringUtils.hasText(vo.getUsername())) {
prop.setProperty("username", vo.getUsername());
}
if (StringUtils.hasText(vo.getPassword())) {
prop.setProperty("password", vo.getPassword());
}
if (StringUtils.hasText(vo.getUrl())) {
prop.setProperty("url", vo.getUrl());
}
if (StringUtils.hasText(vo.getDriverClassName())) {
prop.setProperty("driverClassName", vo.getDriverClassName());
}
prop.store(Files.newOutputStream(Paths.get(DataSourceUtils.PATH)), "");
DataSourceUtils.refresh(DataSourceUtils.PATH);
}
}
return "url: " + Optional.ofNullable(vo).orElse(new DataSourceRequestVO()).getUrl();
}
}
9.测试接口
package app.controller;
import app.domain.entity.User;
import app.mapper.UserMapper;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
import java.util.UUID;
@RestController
public class UserController {
@Resource
private UserMapper userMapper;
@GetMapping("/user/list")
public Object list() {
return userMapper.list();
}
/**
* 正常提交
* @return
*/
@Transactional
@PostMapping("/save")
public String save() {
User user = new User();
user.setUsername(UUID.randomUUID().toString());
userMapper.insert(user);
return "success";
}
/**
* 异常回滚
* @return
*/
@Transactional
@PostMapping("/saveRollback")
public String saveRollback() {
User user = new User();
user.setUsername(UUID.randomUUID().toString());
userMapper.insert(user);
throw new RuntimeException();
}
}
10.测试
// 切换到test1数据库
POST localhost:8080/db/save
{
"username": "root",
"password": "root",
"url": "jdbc:mysql://localhost:3306/test1"
}
//查询用户
GEE localhost:8080/user/list
//正常提交测试
localhost:8080/save
//异常回滚测试
localhost:8080/saveRollback
//===============================================================
// 切换到test2数据库
POST localhost:8080/db/save
{
"username": "root",
"password": "root",
"url": "jdbc:mysql://localhost:3306/test2"
}
//正常提交测试
localhost:8080/save
//异常回滚测试
localhost:8080/saveRollback
//查询用户
GEE localhost:8080/user/list