遇到问题可参考下面文章内容
https://blog.csdn.net/qq_58233406/article/details/126914605
CREATE DATABASE /*!32312 IF NOT EXISTS*/`springboot` /*!40100 DEFAULT
CHARACTER SET utf8 */;
USE `springboot`;
/*Table structure for table `department` */
DROP TABLE IF EXISTS `department`;
CREATE TABLE `department` (
`id` int(3) NOT NULL AUTO_INCREMENT COMMENT '部门id',
`department_name` varchar(20) NOT NULL COMMENT '部门名字',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=106 DEFAULT CHARSET=utf8;
/*Data for the table `department` */
insert into `department`(`id`,`department_name`) values (101,'技术部'),
(102,'销售部'),(103,'售后部'),(104,'后勤部'),(105,'运营部');
/*Table structure for table `employee` */
DROP TABLE IF EXISTS `employee`;
CREATE TABLE `employee` (
`id` int(5) NOT NULL AUTO_INCREMENT COMMENT '雇员id',
`last_name` varchar(100) NOT NULL COMMENT '名字',
`email` varchar(100) NOT NULL COMMENT '邮箱',
`gender` int(2) NOT NULL COMMENT '性别1 男, 0 女',
`department` int(3) NOT NULL COMMENT '部门id',
`birth` datetime NOT NULL COMMENT '生日',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1006 DEFAULT CHARSET=utf8;
/*Data for the table `employee` */
insert into
`employee`(`id`,`last_name`,`email`,`gender`,`department`,`birth`) values
(1001,'张三','[email protected]',1,101,'2021-03-06 15:04:33'),(1002,'李
四','[email protected]',1,102,'2021-03-06 15:04:36'),(1003,'王
五','[email protected]',0,103,'2021-03-06 15:04:37'),(1004,'赵
六','[email protected]',1,104,'2021-03-06 15:04:39'),(1005,'孙
七','[email protected]',0,105,'2021-03-06 15:04:45');
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-jdbcartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<scope>runtimescope>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
dependency>
dependencies>
spring:
datasource:
username: root
password: 1234
url: jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8
driver-class-name: com.mysql.jdbc.Driver
补充:Mysql8.0
版本为如下配置
spring:
datasource:
username: root
password: 1234
# ?serverTimezone=UTC解决时区的报错
url: jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
driver-class-name: com.mysql.cj.jdbc.Driver
package com.example.springboot06data;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;
@SpringBootTest
class SpringBoot06DataApplicationTests {
@Autowired
DataSource dataSource;
@Test
void contextLoads() throws SQLException {
// 查看默认数据源
System.out.println(dataSource.getClass());
// 获得连接
Connection connection = dataSource.getConnection();
System.out.println(connection);
// 关闭连接
connection.close();
}
}
可以看到:默认数据源为 class com.zaxxer.hikari.HikariDataSource
补充:如果datasource报错,就降低springboot版本,我原本使用的2.7.3虽然报红线但是还可以使用,不想报红线可以降低版本为2.6.11
全局搜索:DataSourceAutoConfiguration
文件
@Import({Hikari.class, Tomcat.class, Dbcp2.class, OracleUcp.class, Generic.class, DataSourceJmxConfiguration.class})
protected static class PooledDataSourceConfiguration {
protected PooledDataSourceConfiguration() {
}
}
JdbcTemplate
。JdbcTemplate
。JdbcTemplate主要提供以下几类方法:
/**
* 查询employee表中所有数据
* List 中的1个 Map 对应数据库的 1行数据
* Map 中的 key 对应数据库的字段名,value 对应数据库的字段值
*/
@GetMapping("/list")
public List<Map<String,Object>> userList() {
String sql = "select * from employee";
List<Map<String,Object>> maps = jdbcTemplate.queryForList(sql);
return maps;
}
/**
* 增加员工
*/
@GetMapping("/add")
public int add(){
//new Date().toLocaleString默认设置为12小时,会显示上午、下午.可设置为24小时var time=new Date().toLocaleString('chinese',{hour12:false});
String sql = "insert into employee(`last_Name`,`email`,`gender`,`department`,`birth`) values('BoBooY','[email protected]',1,105,'" + new Date().toLocaleString()+"')";
int updateRows = jdbcTemplate.update(sql);
return updateRows;
}
/**
* 修改员工
*/
@GetMapping("/update/{id}")
public int update(@PathVariable("id") int id) {
String sql = "update employee set last_Name=?,email=? where id=" + id;
Object[] data = new Object[2];
data[0] = "BoBooY";
data[1] = "[email protected]";
int updateRows = jdbcTemplate.update(sql,data);
return updateRows;
}
/**
* 删除员工
*/
@GetMapping("/delete/{id}")
public int delete(@PathVariable("id") int id) {
String sql = "delete from employee where id="+ id;
int updateRows = jdbcTemplate.update(sql);
return updateRows;
}
JdbcController
)package com.example.springboot06data.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import java.util.Date;
import java.util.List;
import java.util.Map;
/**
* @author BoBooY
* @date 2022/9/14 21:44
*/
@RestController
public class JdbcController {
/**
* Spring Boot 默认提供了数据源,默认提供了 org.springframework.jdbc.core.JdbcTemplate
* JdbcTemplate 中会自己注入数据源,用于简化 JDBC操作
* 还能避免一些常见的错误,使用起来也不用再自己来关闭数据库连接
*/
@Autowired
JdbcTemplate jdbcTemplate;
/**
* 查询employee表中所有数据
* List 中的1个 Map 对应数据库的 1行数据
* Map 中的 key 对应数据库的字段名,value 对应数据库的字段值
*/
@GetMapping("/list")
public List<Map<String,Object>> userList() {
String sql = "select * from employee";
List<Map<String,Object>> maps = jdbcTemplate.queryForList(sql);
return maps;
}
/**
* 增加员工
*/
@GetMapping("/add")
public int add(){
//new Date().toLocaleString默认设置为12小时,会显示上午、下午.可设置为24小时var time=new Date().toLocaleString('chinese',{hour12:false});
String sql = "insert into employee(`last_Name`,`email`,`gender`,`department`,`birth`) values('BoBooY','[email protected]',1,105,'" + new Date().toLocaleString()+"')";
int updateRows = jdbcTemplate.update(sql);
return updateRows;
}
/**
* 修改员工
*/
@GetMapping("/update/{id}")
public int update(@PathVariable("id") int id) {
String sql = "update employee set last_Name=?,email=? where id=" + id;
Object[] data = new Object[2];
data[0] = "BoBooY";
data[1] = "[email protected]";
int updateRows = jdbcTemplate.update(sql,data);
return updateRows;
}
/**
* 删除员工
*/
@GetMapping("/delete/{id}")
public int delete(@PathVariable("id") int id) {
String sql = "delete from employee where id="+ id;
int updateRows = jdbcTemplate.update(sql);
return updateRows;
}
}
com.alibaba.druid.pool.DruidDataSource 基本配置参数如下:
配置 | 缺省值 | 说明 |
---|---|---|
name | 配置这个属性的意义在于,如果存在多个数据源,监控的时候可以通过名字来区分开来。如果没有配置,将会生成一个名字,格式是:“DataSource-” + System.identityHashCode(this). | |
url | 连接数据库的url,不同数据库不一样。例如: mysql: jdbc:mysql://10.20.153.104:3306/druid2 oracle: jdbc:oracle:thin:@10.20.149.85:1521:ocnauto | |
username | 连接数据库的用户名 | |
password | 连接数据库的密码。如果你不希望密码直接写在配置文件中,可以使用ConfigFilter。 | |
driverClassName | 根据url自动识别 | 这一项可配可不配,如果不配置druid会根据url自动识别dbType,然后选择相应的driverClassName |
initalSize | 0 | 初始化时建立物理连接的个数。初始化发生在显示调用init方法,或者第一次getConnection时 |
maxActive | 8 | 最大连接池数量 |
maxIdle | 8 | 已经不再使用,配置了也没效果 |
minIdle | 最小连接池数量 | |
maxWait | 获取连接时最大等待时间,单位毫秒。配置了maxWait之后,缺省启用公平锁,并发效率会有所下降,如果需要可以通过配置useUnfairLock属性为true使用非公平锁。 | |
poolPreparedStatements | false | 是否缓存preparedStatement,也就是PSCache。PSCache对支持游标的数据库性能提升巨大,比如说oracle。在mysql下建议关闭。 |
maxOpenPreparedStatements | -1 | 要启用PSCache,必须配置大于0,当大于0时,poolPreparedStatements自动触发修改为true。在Druid中,不会存在Oracle下PSCache占用内存过多的问题,可以把这个数值配置大一些,比如说100 |
validationQuery | 用来检测连接是否有效的sql,要求是一个查询语句。如果validationQuery为null,testOnBorrow、testOnReturn、testWhileIdle都不会其作用。 | |
validationQueryTimeout | 单位:秒,检测连接是否有效的超时时间。底层调用jdbc Statement对象的void setQueryTimeout(int seconds)方法。 | |
testOnBorrow | true | 申请连接时执行validationQuery检测连接是否有效,做了这个配置会降低性能。 |
testOnReturn | false | 归还连接时执行validationQuery检测连接是否有效,做了这个配置会降低性能 |
testWhileIdle | false | 建议配置为true,不影响性能,并且保证安全性。申请连接的时候检测,如果空闲时间大于timeBetweenEvictionRunsMillis,执行validationQuery检测连接是否有效。 |
timeBetweenEvictionRunsMillis | 1分钟 (1.0.14) | 有两个含义: 1) Destroy线程会检测连接的间隔时间,如果连接空闲时间大于等于minEvictableIdleTimeMillis则关闭物理连接 2) testWhileIdle的判断依据,详细看testWhileIdle属性的说明。 |
numTestsPerEvictionRun | 不再使用,一个DruidDataSource只支持一个EvictionRun | |
numTestsPerEvictionRun | 30分钟 (1.0.14) | 连接保持空闲而不被驱逐的最长时间 |
connectionInitSqls | 物理连接初始化的时候执行的sql | |
exceptionSorter | 根据dbType自动识别 | 当数据库抛出一些不可恢复的异常时,抛弃连接 |
filters | 属性类型是字符串,通过别名的方式配置扩展插件,常用 的插件有:监控统计用的filter:stat 日志用的filter:log4j 防御sql注入的filter:wall | |
proxyFilters | 类型是List,如果同时配置了filters和proxyFilters,是组合关系,并非替换关系 |
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>1.2.6version>
dependency>
spring:
datasource:
username: root
password: root
# ?serverTimezone=UTC解决时区的报错
url: jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
driver-class-name: com.mysql.cj.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource # 自定义数据源
spring:
datasource:
username: root
password: 1234
url: jdbc:mysql://localhost:3306/springboot?useSSL=true&useUnicode=true&characterEncoding=utf8
driver-class-name: com.mysql.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource # 自定义数据源
#数据源
#Spring Boot 默认是不注入这些属性值的,需要自己绑定
#druid 数据源专有配置
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
#配置监控统计拦截的filters,stat:监控统计、log4j:日志记录、wall:防御sql注入
#如果允许时报错 java.lang.ClassNotFoundException: org.apache.log4j.Priority
#则导入 log4j 依赖即可,Maven 地址:https://mvnrepository.com/artifact/log4j/log4j
filters: stat,wall,log4j
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
<dependency>
<groupId>log4jgroupId>
<artifactId>log4jartifactId>
<version>1.2.17version>
dependency>
DruidConfig
import java.util.HashMap;
import java.util.Map;
/**
* @author BoBooY
* @date 2022/9/17 17:19
*/
@Configuration
public class DruidConfig {
/**
* 将自定义的 Druid数据源添加到容器中,不再让 Spring Boot 自动创建
* 绑定全局配置文件中的 druid 数据源属性到 com.alibaba.druid.pool.DruidDataSource从而让它们生效
*
* @ConfigurationProperties(prefix = "spring.datasource"):作用就是将 全局配置文件中
* 前缀为 spring.datasource的属性值注入到 com.alibaba.druid.pool.DruidDataSource 的同名参数中
*/
@ConfigurationProperties(prefix = "spring.datasource")
@Bean
public DataSource druidDataSource() {
return new DruidDataSource();
}
}
DruidConfig
@Bean
public ServletRegistrationBean statViewServlet() {
ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
// 这些参数可以在 com.alibaba.druid.support.http.StatViewServlet的父类 com.alibaba.druid.support.http.ResourceServlet 中找到
Map<String, String> initParams = new HashMap<>();
initParams.put("loginUsername", "admin");
initParams.put("loginPassword", "123456");
// deny:Druid 后台拒绝谁访问
// initParams.put("deny", "192.168.1.20");表示禁止此ip访问
bean.setInitParameters(initParams);
return bean;
}
DruidConfig
// 配置 Druid 监控 之 web 监控的 filter
// WebStatFilter:用于配置Web和Druid数据源之间的管理关联监控统计
@Bean
public FilterRegistrationBean webStatFilter() {
FilterRegistrationBean bean = new FilterRegistrationBean();
bean.setFilter(new WebStatFilter());
// exclusions:设置哪些请求进行过滤排除掉,从而不进行统计
HashMap<String, String> initParams = new HashMap<>();
initParams.put("exclusions","*.js,*.css,/druid/*,/jdbc/*");
bean.setInitParameters(initParams);
// "/*" 表示过滤所有请求
bean.setUrlPatterns(Arrays.asList("/*"));
return bean;
}
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
<version>2.2.2version>
dependency>
spring:
datasource:
username: root
password: 1234
url: jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=utf8
driver-class-name: com.mysql.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource # 自定义数据源
#数据源
#Spring Boot 默认是不注入这些属性值的,需要自己绑定
#druid 数据源专有配置
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
#配置监控统计拦截的filters,stat:监控统计、log4j:日志记录、wall:防御sql注入
#如果允许时报错 java.lang.ClassNotFoundException: org.apache.log4j.Priority
#则导入 log4j 依赖即可,Maven 地址:https://mvnrepository.com/artifact/log4j/log4j
filters: stat,wall,log4j
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
package com.springboot07mybatis.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
/**
* @author BoBooY
* @date 2022/9/17 21:07
*/
@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
private int id;
private String name;
private String pwd;
}
package com.springboot07mybatis.mapper;
import com.springboot07mybatis.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import java.util.List;
/**
* @author BoBooY
* @date 2022/9/17 21:08
*/
@Repository
@Mapper
public interface UserMapper {
List<User> getUserList();
User getUserById(int id);
int addUser(User user);
int updateUser(User user);
int deleteUser(int id);
}
DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.springboot07mybatis.mapper.UserMapper">
<select id="getUserList" resultType="User">
select * from user
select>
<select id="getUserById" resultType="User" parameterType="int">
select * from user where id = #{id}
select>
<insert id="addUser" parameterType="User">
insert into user(`name`,`pwd`) values(#{name},#{pwd})
insert>
<update id="updateUser" parameterType="User">
update user set `name`=#{name},`pwd`=#{pwd} where `id`=#{id}
update>
<delete id="deleteUser" parameterType="int">
delete from user where `id`=#{id}
delete>
mapper>
#配置Mybatis
mybatis:
# 指定myBatis的核心配置文件与Mapper映射文件
mapper-locations: classpath:mybatis/mapper/*.xml
# 注意:对应实体类的路径
type-aliases-package: com.springboot07mybatis.pojo
<build>
<resources>
<resource>
<directory>src/main/javadirectory>
<includes>
<include>**/*.propertiesinclude>
<include>**/*.xmlinclude>
<include>**/*.ymlinclude>
<include>**/*.yamlinclude>
includes>
<filtering>falsefiltering>
resource>
<resource>
<directory>src/main/resourcesdirectory>
<includes>
<include>**/*.propertiesinclude>
<include>**/*.xmlinclude>
<include>**/*.ymlinclude>
<include>**/*.yamlinclude>
includes>
<filtering>falsefiltering>
resource>
resources>
build>
package com.springboot07mybatis.controller;
import com.springboot07mybatis.mapper.UserMapper;
import com.springboot07mybatis.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
/**
* @author BoBooY
* @date 2022/9/17 21:25
*/
@RestController
public class UserController {
@Autowired
UserMapper userMapper;
@GetMapping("/getUsers")
public List<User> getUsers() {
List<User> users = userMapper.getUserList();
for (User user : users) {
System.out.println(user);
}
return users;
}
@GetMapping("/getUser/{id}")
public User getUser(@PathVariable("id") int id) {
User user = userMapper.getUserById(id);
return user;
}
@GetMapping("/updateUser")
public String updateUser() {
User user = getUser(4);
user.setName("laosi");
user.setPwd("1234");
int i = userMapper.updateUser(user);
if(i > 0) {
return "修改成功";
} else {
return "修改失败";
}
}
@GetMapping("/addUser")
public String addUser() {
User user = new User();
user.setName("老五");
user.setPwd("123");
int i = userMapper.addUser(user);
if(i > 0) {
return "添加成功";
} else {
return "添加失败";
}
}
@GetMapping("/deleteUser/{id}")
public String deleteUser(@PathVariable("id") int id) {
int i = userMapper.deleteUser(id);
if(i > 0) {
return "删除成功";
} else {
return "删除失败";
}
}
}