Springboot让Java开发更加美好,本节主要讲的是使用Hikari数据库连接池,如果需要使用druid连接池的请看我另外一篇博客,springboot Mybatis 整合(这篇文章有详细搭建springboot项目的过程,对于刚接触springboot的新手有帮助)。
在Springboot2.X版本,数据库的连接池官方推荐使用HikariCP,官方的原话:
Production database connections can also be auto-configured by using a pooling
DataSource
. Spring Boot uses the following algorithm for choosing a specific implementation:
We preferHikariCPfor its performance and concurrency. If HikariCP is available, we always choose it.
Otherwise, if the Tomcat pooling
DataSource
is available, we use it.If neither HikariCP nor the Tomcat pooling datasource are available and ifCommons DBCP2is available, we use it.
意思是说:
我们更喜欢HikariCP的性能和并发性。如果有HikariCP,我们总是选择它
否则,如果Tomcat池数据源可用,我们将使用它。
如果HikariCP和Tomcat池数据源都不可用,如果Commons DBCP2可用,我们将使用它。
那么如何使用HikariCP呢?
如果你的springboot版本是2.X,当你使用spring-boot-starter-jdbc
或者spring-boot-starter-data-jpa
依赖,springboot就会自动引入HikariCP的依赖了。
如果你需要使用指定的数据库连接池,那么你需要在application.properties
中配置:spring.datasource.type
JDK: 1.8
Maven: 3.3.9
SpringBoot: 2.0.3.RELEASE
开发工具:Intellij IDEA 2017.1.3
本次的配置中我们持久层使用mybatis,使用HikariCP作为数据库连接池。
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-jdbcartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
<exclusions>
<exclusion>
<groupId>org.apache.tomcatgroupId>
<artifactId>tomcat-jdbcartifactId>
exclusion>
exclusions>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.46version>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
<version>1.3.2version>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
dependency>
以上的依赖就足够了,前面介绍过,只需要导入spring-boot-starter-jdbc
依赖springboot就默认使用Hikari作为数据库连接池了。
CREATE DATABASE mytest;
CREATE TABLE t_user(
userId INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
userName VARCHAR(255) NOT NULL ,
password VARCHAR(255) NOT NULL ,
phone VARCHAR(255) NOT NULL
) ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8;
package com.winterchen.model;
/**
* Created by Donghua.Chen on 2018/7/25.
*/
public class UserDomain {
private Integer userId;
private String userName;
private String password;
private String phone;
// @TODO 省略get/set
}
创建一个dao的包,并且在这个包下创建一个UserDao
package com.winterchen.dao;
import com.winterchen.model.UserDomain;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;
/**
* Created by Donghua.Chen on 2018/7/25.
*/
@Mapper
public interface UserDao {
int insert(UserDomain record);
void deleteUserById(@Param("userId") Integer userId);
void updateUser(UserDomain userDomain);
List selectUsers();
}
注意:一定不要忘了使用@Mapper
注解,如果没有这个注解,spring就无法扫描到这个类,导致项目启动报错。
上一步我们创建dao数据库持久层类,由于本文使用的是xml映射的方式,所以我们需要创建一个xml映射文件。
在resources
文件夹下新建一个文件夹mapper
:
<mapper namespace="com.winterchen.dao.UserDao" >
<sql id="BASE_TABLE">
t_user
sql>
<sql id="BASE_COLUMN">
userId,userName,password,phone
sql>
<insert id="insert" parameterType="com.winterchen.model.UserDomain">
INSERT INTO
<include refid="BASE_TABLE"/>
<trim prefix="(" suffix=")" suffixOverrides=",">
userName,password,
<if test="phone != null">
phone,
if>
trim>
<trim prefix="VALUES(" suffix=")" suffixOverrides=",">
#{userName, jdbcType=VARCHAR},#{password, jdbcType=VARCHAR},
<if test="phone != null">
#{phone, jdbcType=VARCHAR},
if>
trim>
insert>
<delete id="deleteUserById">
DELETE FROM
<include refid="BASE_TABLE"/>
WHERE
userId = #{userId, jdbcType=INTEGER}
delete>
<update id="updateUser" parameterType="com.winterchen.model.UserDomain">
UPDATE
<include refid="BASE_TABLE"/>
<set>
<if test="userName != null">
userName = #{userName, jdbcType=VARCHAR},
if>
<if test="password != null">
password = #{password, jdbcType=VARCHAR},
if>
<if test="phone != null">
phone = #{phone, jdbcType=VARCHAR},
if>
set>
<where>
userId = #{userId, jdbcType=INTEGER}
where>
update>
<select id="selectUsers" resultType="com.winterchen.model.UserDomain">
SELECT
<include refid="BASE_COLUMN"/>
FROM
<include refid="BASE_TABLE"/>
select>
mapper>
注意点: 请将namespace="com.winterchen.dao.UserDao"
改为你自己项目Dao的路径,以及下面方法的一些路径都要改为你自己项目的相关路径。
server.port=8080
#### 数据库连接池属性
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/mytest?useSSL=false&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true
spring.datasource.username=root
spring.datasource.password=root
#自动提交
spring.datasource.default-auto-commit=true
#指定updates是否自动提交
spring.datasource.auto-commit=true
spring.datasource.maximum-pool-size=100
spring.datasource.max-idle=10
spring.datasource.max-wait=10000
spring.datasource.min-idle=5
spring.datasource.initial-size=5
spring.datasource.validation-query=SELECT 1
spring.datasource.test-on-borrow=false
spring.datasource.test-while-idle=true
# 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒
spring.datasource.time-between-eviction-runs-millis=18800
# 配置一个连接在池中最小生存的时间,单位是毫秒
spring.datasource.minEvictableIdleTimeMillis=300000
# mybatis对应的映射文件路径
mybatis.mapper-locations=classpath:mapper/*.xml
# mybatis对应的实体类
mybatis.type-aliases-package=com.winterchen.model
package com.winterchen.service;
import com.winterchen.model.UserDomain;
import java.util.List;
/**
* Created by Donghua.Chen on 2018/7/25.
*/
public interface UserService {
int insert(UserDomain record);
void deleteUserById(Integer userId);
void updateUser(UserDomain userDomain);
List selectUsers();
}
package com.winterchen.service.impl;
import com.winterchen.dao.UserDao;
import com.winterchen.model.UserDomain;
import com.winterchen.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
/**
* Created by Donghua.Chen on 2018/7/25.
*/
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserDao userDao;//这里会爆红,请忽略
@Override
public int insert(UserDomain record) {
return userDao.insert(record);
}
@Override
public void deleteUserById(Integer userId) {
userDao.deleteUserById(userId);
}
@Override
public void updateUser(UserDomain userDomain) {
userDao.updateUser(userDomain);
}
@Override
public List selectUsers() {
return userDao.selectUsers();
}
}
package com.winterchen.controller;
import com.winterchen.model.UserDomain;
import com.winterchen.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
/**
* Created by Donghua.Chen on 2018/7/25.
*/
@RestController
@RequestMapping("/user")
public class UserController {
@Autowired
private UserService userService;
@PostMapping("")
public ResponseEntity addUser(
@RequestParam(value = "userName", required = true)
String userName,
@RequestParam(value = "password", required = true)
String password,
@RequestParam(value = "phone", required = false)
String phone
){
UserDomain userDomain = new UserDomain();
userDomain.setUserName(userName);
userDomain.setPassword(password);
userDomain.setPhone(phone);
userService.insert(userDomain);
return ResponseEntity.ok("添加成功");
}
@DeleteMapping("")
public ResponseEntity deleteUser(@RequestParam(value = "userId", required = true) Integer userId){
userService.deleteUserById(userId);
return ResponseEntity.ok("删除成功");
}
@PutMapping("")
public ResponseEntity updateUser(
@RequestParam(value = "userId", required = true)
Integer userId,
@RequestParam(value = "userName", required = false)
String userName,
@RequestParam(value = "password", required = false)
String password,
@RequestParam(value = "phone", required = false)
String phone
){
UserDomain userDomain = new UserDomain();
userDomain.setUserId(userId);
userDomain.setUserName(userName);
userDomain.setPassword(password);
userDomain.setPhone(phone);
userService.updateUser(userDomain);
return ResponseEntity.ok("更新成功");
}
@GetMapping("")
public ResponseEntity getUsers(){
return ResponseEntity.ok(userService.selectUsers());
}
}
强行科普一下:
@RequestParam
用于将请求参数区数据映射到功能处理方法的参数上,value
:参数名字,即入参的请求参数名字,如userName表示请求的参数区中的名字为userName的参数的值将传入,required
:是否必须,默认是true,表示请求中一定要有相应的参数,否则将报404错误码;
@Controller和@RestController的区别?
package com.winterchen;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringBootMybatisHikaricpApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootMybatisHikaricpApplication.class, args);
}
}
启动项目启动类
2018-07-25 15:25:42.970 INFO 22602 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-07-25 15:25:43.380 INFO 22602 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-07-25 15:25:43.382 INFO 22602 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Bean with name 'dataSource' has been autodetected for JMX exposure
2018-07-25 15:25:43.389 INFO 22602 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Located MBean 'dataSource': registering with JMX server as MBean [com.zaxxer.hikari:name=dataSource,type=HikariDataSource]
2018-07-25 15:25:43.450 INFO 22602 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2018-07-25 15:25:43.456 INFO 22602 --- [ main] c.w.SpringBootMybatisHikaricpApplication : Started SpringBootMybatisHikaricpApplication in 6.267 seconds (JVM running for 7.784)
这样的输出表示项目启动成功了!!如果遇到报错启动不了,请回头看看是不是有些地方没有注意到。
项目成功启动了,那么可以开始测试了
推荐使用一个强大的http请求工具:Postman
在编程的路上肯定会遇到很多的bug,程序员就是要不断的和bug作斗争,加油,愿你成为真正的大牛。有机会讲讲Hikari如何使用多数据源。
源码地址:戳这里
springboot技术交流群:681513531
个人博客:https://winterchen.com