springboot配置数据源
Spring Framework 为 SQL 数据库提供了广泛的支持。从直接使用 JdbcTemplate 进行 JDBC 访问到完全的对象关系映射（object relational mapping）技术，比如 Hibernate。Spring Data 提供了更多级别的功能，直接从接口创建的 Repository 实现，并使用了约定从方法名生成查询。
1、JDBC
1、创建项目，导入需要的依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
2、配置数据源
spring:
datasource:
username: root
password: 123456
url: jdbc:mysql://192.168.85.111:3306/sakila?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
driver-class-name: com.mysql.jdbc.Driver
3、测试类代码
package com.mashibing;
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 DataApplicationTests {
@Autowired
DataSource dataSource;
@Test
void contextLoads() throws SQLException {
System.out.println(dataSource.getClass());
Connection connection = dataSource.getConnection();
System.out.println(connection);
connection.close();
}
}
//可以看到默认配置的数据源为class com.zaxxer.hikari.HikariDataSource，我们没有经过任何配置，说明springboot默认情况下支持的就是这种数据源，可以在DataSourceProperties.java文件中查看具体的属性配置
4、crud操作
1、有了数据源(com.zaxxer.hikari.HikariDataSource)，然后可以拿到数据库连接(java.sql.Connection)，有了连接，就可以使用连接和原生的 JDBC 语句来操作数据库
2、即使不使用第三方第数据库操作框架，如 MyBatis等，Spring 本身也对原生的JDBC 做了轻量级的封装，即 org.springframework.jdbc.core.JdbcTemplate。
3、数据库操作的所有 CRUD 方法都在 JdbcTemplate 中。
4、Spring Boot 不仅提供了默认的数据源，同时默认已经配置好了 JdbcTemplate 放在了容器中，程序员只需自己注入即可使用
5、JdbcTemplate 的自动配置原理是依赖 org.springframework.boot.autoconfigure.jdbc 包下的 org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration 类
package com.mashibing.contoller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
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;
import java.util.Map;
@RestController
public class JDBCController {
@Autowired
JdbcTemplate jdbcTemplate;
@GetMapping("/emplist")
public List<Map<String,Object>> empList(){
String sql = "select * from emp";
List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql);
return maps;
}
@GetMapping("/addEmp")
public String addUser(){
String sql = "insert into emp(empno,ename) values(1111,'zhangsan')";
jdbcTemplate.update(sql);
return "success";
}
@GetMapping("/updateEmp/{id}")
public String updateEmp(@PathVariable("id") Integer id){
String sql = "update emp set ename=? where empno = "+id;
String name = "list";
jdbcTemplate.update(sql,name);
return "update success";
}
@GetMapping("/deleteEmp/{id}")
public String deleteEmp(@PathVariable("id")Integer id){
String sql = "delete from emp where empno = "+id;
jdbcTemplate.update(sql);
return "delete success";
}
}
2、自定义数据源DruidDataSource
通过源码查看DataSourceAutoConfiguration.java
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ DataSource.class, EmbeddedDatabaseType.class })
@EnableConfigurationProperties(DataSourceProperties.class)
@Import({ DataSourcePoolMetadataProvidersConfiguration.class, DataSourceInitializationConfiguration.class })
public class DataSourceAutoConfiguration {
@Configuration(proxyBeanMethods = false)
@Conditional(EmbeddedDatabaseCondition.class)
@ConditionalOnMissingBean({ DataSource.class, XADataSource.class })
@Import(EmbeddedDataSourceConfiguration.class)
protected static class EmbeddedDatabaseConfiguration {
}
@Configuration(proxyBeanMethods = false)
@Conditional(PooledDataSourceCondition.class)
@ConditionalOnMissingBean({ DataSource.class, XADataSource.class })
@Import({ DataSourceConfiguration.Hikari.class, DataSourceConfiguration.Tomcat.class,
DataSourceConfiguration.Dbcp2.class, DataSourceConfiguration.Generic.class,
DataSourceJmxConfiguration.class })
protected static class PooledDataSourceConfiguration {
}
/**
* {@link AnyNestedCondition} that checks that either {@code spring.datasource.type}
* is set or {@link PooledDataSourceAvailableCondition} applies.
*/
static class PooledDataSourceCondition extends AnyNestedCondition {
PooledDataSourceCondition() {
super(ConfigurationPhase.PARSE_CONFIGURATION);
}
@ConditionalOnProperty(prefix = "spring.datasource", name = "type")
static class ExplicitType {
}
@Conditional(PooledDataSourceAvailableCondition.class)
static class PooledDataSourceAvailable {
}
}
1、添加druid的maven配置
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.12</version>
</dependency>
2、添加数据源的配置
spring:
datasource:
username: root
password: 123456
url: jdbc:mysql://192.168.85.111:3306/demo?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
driver-class-name: com.mysql.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource
3、测试发现数据源已经更改
4、druid是数据库连接池，可以添加druid的独有配置
spring:
datasource:
username: root
password: 123456
url: jdbc:mysql://192.168.85.111:3306/demo?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
driver-class-name: com.mysql.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource
#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
测试类，发现配置的参数没有生效
package com.mashibing;
import com.alibaba.druid.pool.DruidDataSource;
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 DataApplicationTests {
@Autowired
DataSource dataSource;
@Test
void contextLoads() throws SQLException {
System.out.println(dataSource.getClass());
Connection connection = dataSource.getConnection();
System.out.println(connection);
DruidDataSource druidDataSource = (DruidDataSource)dataSource;
System.out.println(druidDataSource.getMaxActive());
System.out.println(druidDataSource.getInitialSize());
connection.close();
}
}
需要定义druidDatasource的配置类，绑定参数
package com.mashibing.config;
import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.sql.DataSource;
@Configuration
public class DruidConfig {
@ConfigurationProperties(prefix = "spring.datasource")
@Bean
public DataSource druidDataSource(){
return new DruidDataSource();
}
}
Druid数据源还具有监控的功能，并提供了一个web界面方便用户进行查看。
加入log4j的日志依赖
<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
向DruidConfig中添加代码，配置druid监控管理台的servlet
package com.mashibing.config;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.Servlet;
import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
@Configuration
public class DruidConfig {
@ConfigurationProperties(prefix = "spring.datasource")
@Bean
public DataSource druidDataSource(){
return new DruidDataSource();
}
@Bean
public ServletRegistrationBean druidServletRegistrationBean(){
ServletRegistrationBean<Servlet> servletRegistrationBean = new ServletRegistrationBean<>(new StatViewServlet(),"/druid/*");
Map<String,String> initParams = new HashMap<>();
initParams.put("loginUsername","admin");
initParams.put("loginPassword","123456");
//后台允许谁可以访问
//initParams.put("allow", "localhost")：表示只有本机可以访问
//initParams.put("allow", "")：为空或者为null时，表示允许所有访问
initParams.put("allow","");
//deny：Druid 后台拒绝谁访问
//initParams.put("msb", "192.168.1.20");表示禁止此ip访问
servletRegistrationBean.setInitParameters(initParams);
return servletRegistrationBean;
}
//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
Map<String, String> initParams = new HashMap<>();
initParams.put("exclusions", "*.js,*.css,/druid/*");
bean.setInitParameters(initParams);
//"/*" 表示过滤所有请求
bean.setUrlPatterns(Arrays.asList("/*"));
return bean;
}
}
3、springboot配置多数据源并动态切换
DataSource是和线程绑定的，动态数据源的配置主要是通过继承AbstractRoutingDataSource类实现的，实现在AbstractRoutingDataSource类中的 protected Object determineCurrentLookupKey()方法来获取数据源，所以我们需要先创建一个多线程线程数据隔离的类来存放DataSource，然后在determineCurrentLookupKey()方法中通过这个类获取当前线程的DataSource，在AbstractRoutingDataSource类中，DataSource是通过Key-value的方式保存的，我们可以通过ThreadLocal来保存Key，从而实现数据源的动态切换。
1、修改配置文件类
spring:
datasource:
local:
username: root
password: 123456
driver-class-name: com.mysql.jdbc.Driver
jdbc-url: jdbc:mysql://localhost:3306/demo?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
remote:
username: root
password: 123456
driver-class-name: com.mysql.jdbc.Driver
jdbc-url: jdbc:mysql://192.168.85.111:3306/demo?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
2、创建数据源枚举类
package com.mashibing.mult;
public enum DataSourceType {
REMOTE,
LOCAL
}
3、数据源切换处理
创建一个数据源切换处理类，有对数据源变量的获取、设置和情况的方法，其中threadlocal用于保存某个线程共享变量。
package com.mashibing.mult;
public class DynamicDataSourceContextHolder {
/**
* 使用ThreadLocal维护变量，ThreadLocal为每个使用该变量的线程提供独立的变量副本，
* 所以每一个线程都可以独立地改变自己的副本，而不会影响其它线程所对应的副本。
*/
private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();
/**
* 设置数据源变量
* @param dataSourceType
*/
public static void setDataSourceType(String dataSourceType){
System.out.printf("切换到{%s}数据源", dataSourceType);
CONTEXT_HOLDER.set(dataSourceType);
}
/**
* 获取数据源变量
* @return
*/
public static String getDataSourceType(){
return CONTEXT_HOLDER.get();
}
/**
* 清空数据源变量
*/
public static void clearDataSourceType(){
CONTEXT_HOLDER.remove();
}
}
4、继承AbstractRoutingDataSource
动态切换数据源主要依靠AbstractRoutingDataSource。创建一个AbstractRoutingDataSource的子类，重写determineCurrentLookupKey方法，用于决定使用哪一个数据源。这里主要用到AbstractRoutingDataSource的两个属性defaultTargetDataSource和targetDataSources。defaultTargetDataSource默认目标数据源，targetDataSources（map类型）存放用来切换的数据源。
package com.mashibing.mult;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
import javax.sql.DataSource;
import java.util.Map;
public class DynamicDataSource extends AbstractRoutingDataSource {
public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) {
super.setDefaultTargetDataSource(defaultTargetDataSource);
super.setTargetDataSources(targetDataSources);
// afterPropertiesSet()方法调用时用来将targetDataSources的属性写入resolvedDataSources中的
super.afterPropertiesSet();
}
/**
* 根据Key获取数据源的信息
*
* @return
*/
@Override
protected Object determineCurrentLookupKey() {
return DynamicDataSourceContextHolder.getDataSourceType();
}
}
5、注入数据源
package com.mashibing.mult;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
@Configuration
public class DataSourceConfig {
@Bean
@ConfigurationProperties("spring.datasource.remote")
public DataSource remoteDataSource() {
return DataSourceBuilder.create().build();
}
@Bean
@ConfigurationProperties("spring.datasource.local")
public DataSource localDataSource() {
return DataSourceBuilder.create().build();
}
@Bean(name = "dynamicDataSource")
@Primary
public DynamicDataSource dataSource(DataSource remoteDataSource, DataSource localDataSource) {
Map<Object, Object> targetDataSources = new HashMap<>();
targetDataSources.put(DataSourceType.REMOTE.name(), remoteDataSource);
targetDataSources.put(DataSourceType.LOCAL.name(), localDataSource);
return new DynamicDataSource(remoteDataSource, targetDataSources);
}
}
6、自定义多数据源切换注解
设置拦截数据源的注解，可以设置在具体的类上，或者在具体的方法上
package com.mashibing.mult;
import java.lang.annotation.*;
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataSource {
/**
* 切换数据源名称
*/
DataSourceType value() default DataSourceType.REMOTE;
}
7、AOP拦截类的实现
通过拦截上面的注解，在其执行之前处理设置当前执行SQL的数据源的信息，CONTEXT_HOLDER.set(dataSourceType)这里的数据源信息从我们设置的注解上面获取信息，如果没有设置就是用默认的数据源的信息。
package com.mashibing.mult;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import java.lang.reflect.Method;
@Aspect
@Order(1)
@Component
public class DataSourceAspect {
@Pointcut("@annotation(com.mashibing.mult.DataSource)")
public void dsPointCut() {
}
@Around("dsPointCut()")
public Object around(ProceedingJoinPoint point) throws Throwable {
MethodSignature signature = (MethodSignature) point.getSignature();
Method method = signature.getMethod();
DataSource dataSource = method.getAnnotation(DataSource.class);
if (dataSource != null) {
DynamicDataSourceContextHolder.setDataSourceType(dataSource.value().name());
}
try {
return point.proceed();
} finally {
// 销毁数据源 在执行方法之后
DynamicDataSourceContextHolder.clearDataSourceType();
}
}
}
8、使用切换数据源注解
package com.mashibing.mult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
import java.util.Map;
@RestController
public class EmpController {
@Autowired
JdbcTemplate jdbcTemplate;
@GetMapping("/local")
@DataSource(value = DataSourceType.LOCAL)
public List<Map<String, Object>> local(){
List<Map<String, Object>> maps = jdbcTemplate.queryForList("select * from emp");
return maps;
}
@GetMapping("/remote")
@DataSource(value = DataSourceType.REMOTE)
public List<Map<String, Object>> remote(){
List<Map<String, Object>> maps = jdbcTemplate.queryForList("select * from emp");
return maps;
}
}
9、在启动项目的过程中会发生循环依赖的问题，直接修改启动类即可
package com.mashibing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
public class SpringbootDataApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootDataApplication.class, args);
}
}
4、springboot整合mybatis
1、导入mybatis的依赖
<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.1</version>
</dependency>
2、配置数据源
spring:
datasource:
username: root
password: 123456
url: jdbc:mysql://192.168.85.111:3306/demo?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
driver-class-name: com.mysql.jdbc.Driver
3、测试类
package com.mashibing;
import com.alibaba.druid.pool.DruidDataSource;
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 DataApplicationTests {
@Autowired
DataSource dataSource;
@Test
void contextLoads() throws SQLException {
System.out.println(dataSource.getClass());
Connection connection = dataSource.getConnection();
System.out.println(connection);
System.out.println(connection.getMetaData().getURL());
connection.close();
}
}
4、创建实体类
package com.mashibing.entity;
import java.sql.Date;
import java.util.Objects;
public class Emp {
private Integer empno;
private String ename;
private String job;
private Integer mgr;
private Date hiredate;
private Double sal;
private Double comm;
private Integer deptno;
public Emp() {
}
public Emp(Integer empno, String ename) {
this.empno = empno;
this.ename = ename;
}
public Emp(Integer empno, String ename, String job, Integer mgr, Date hiredate, Double sal, Double comm, Integer deptno) {
this.empno = empno;
this.ename = ename;
this.job = job;
this.mgr = mgr;
this.hiredate = hiredate;
this.sal = sal;
this.comm = comm;
this.deptno = deptno;
}
public Integer getEmpno() {
return empno;
}
public void setEmpno(Integer empno) {
this.empno = empno;
}
public String getEname() {
return ename;
}
public void setEname(String ename) {
this.ename = ename;
}
public String getJob() {
return job;
}
public void setJob(String job) {
this.job = job;
}
public Integer getMgr() {
return mgr;
}
public void setMgr(Integer mgr) {
this.mgr = mgr;
}
public Date getHiredate() {
return hiredate;
}
public void setHiredate(Date hiredate) {
this.hiredate = hiredate;
}
public Double getSal() {
return sal;
}
public void setSal(Double sal) {
this.sal = sal;
}
public Double getComm() {
return comm;
}
public void setComm(Double comm) {
this.comm = comm;
}
public Integer getDeptno() {
return deptno;
}
public void setDeptno(Integer deptno) {
this.deptno = deptno;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof Emp)) return false;
Emp emp = (Emp) o;
return Objects.equals(empno, emp.empno) &&
Objects.equals(ename, emp.ename) &&
Objects.equals(job, emp.job) &&
Objects.equals(mgr, emp.mgr) &&
Objects.equals(hiredate, emp.hiredate) &&
Objects.equals(sal, emp.sal) &&
Objects.equals(comm, emp.comm) &&
Objects.equals(deptno, emp.deptno);
}
@Override
public int hashCode() {
return Objects.hash(empno, ename, job, mgr, hiredate, sal, comm, deptno);
}
@Override
public String toString() {
return "Emp{" +
"empno=" + empno +
", ename='" + ename + '\'' +
", job='" + job + '\'' +
", mgr=" + mgr +
", hiredate=" + hiredate +
", sal=" + sal +
", comm=" + comm +
", deptno=" + deptno +
'}';
}
}
5、配置Mapper接口类
package com.mashibing.mapper;
import com.mashibing.entity.Emp;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper
@Repository
public interface EmpMapper {
List<Emp> selectEmp();
Emp selectEmpById(Integer empno);
Integer addEmp(Emp emp);
Integer updateEmp(Emp emp);
Integer deleteEmp(Integer empno);
}
6、在resources下创建Emp.xml文件
<?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="com.mashibing.mapper.EmpMapper">
<select id="selectEmp" resultType="Emp">
select * from emp
</select>
<select id="selectEmpById" resultType="Emp">
select * from emp where empno = #{empno}
</select>
<insert id="addEmp" parameterType="Emp">
insert into emp (empno,ename) values (#{empno},#{ename})
</insert>
<update id="updateEmp" parameterType="Emp">
update emp set ename=#{ename} where empno = #{empno}
</update>
<delete id="deleteEmp" parameterType="int">
delete from emp where empno = #{empno}
</delete>
</mapper>
7、添加配置文件
spring:
datasource:
username: root
password: 123456
url: jdbc:mysql://192.168.85.111:3306/demo?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
driver-class-name: com.mysql.jdbc.Driver
mybatis:
mapper-locations: classpath:mybatis/mapper/*.xml
type-aliases-package: com.mashibing.entity
8、编写controller
package com.mashibing.contoller;
import com.mashibing.entity.Emp;
import com.mashibing.mapper.EmpMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
public class EmpController {
@Autowired
private EmpMapper empMapper;
//选择全部用户
@GetMapping("/selectEmp")
public String selectEmp(){
List<Emp> emps = empMapper.selectEmp();
for (Emp Emp : emps) {
System.out.println(Emp);
}
return "ok";
}
//根据id选择用户
@GetMapping("/selectEmpById")
public String selectEmpById(){
Emp emp = empMapper.selectEmpById(1234);
System.out.println(emp);
return "ok";
}
//添加一个用户
@GetMapping("/addEmp")
public String addEmp(){
empMapper.addEmp(new Emp(1234,"heheda"));
return "ok";
}
//修改一个用户
@GetMapping("/updateEmp")
public String updateEmp(){
empMapper.updateEmp(new Emp(1234,"heihei"));
return "ok";
}
//根据id删除用户
@GetMapping("/deleteEmp")
public String deleteEmp(){
empMapper.deleteEmp(1234);
return "ok";
}
}
9、测试即可
