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SpringBoot
什么是SpringBoot
快速启动一个生产级的项目,简化开发流程
回顾SSM
- 复杂、大量的配置文件
- 大量的依赖,没有人管理(容易造成依赖冲突,高低版本不兼容)
SpringBoot能解决上述问题
-
只需要一个配置文件,配置文件的名称必须是 application-.properties或者是 application-.yml这种形式命名
application-dev.properties
application-pro.properties
jdbc.driverClassName = com.mysql.jdbc.Driver jdbc.url = jdbc:mysql://localhost:3306/java2demo?useUnicode=true&characterEncoding=utf8 jdbc.username = root jdbc.password = root
但是SpringBoot更推荐使用.yml文件去作为配置文件
application-dev.yml:开发环境
application-pro.yml:生产环境
application-dev.yaml
application-pro.yaml
jdbc:
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/java2demo?useUnicode=true&characterEncoding=utf8
username: root
password: root
- SpringBoot项目有一个“依赖”的父工程,可以引入其他启动器依赖完成依赖管理
创建SpringBoot项目
- 1.创建maven项目有
-
2.在pom.xml中引入父工程
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.neuedu</groupId> <artifactId>springbootdemo1</artifactId> <version>1.0-SNAPSHOT</version> <!-- 引入父工程,当前最新版本2.1.5 --> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.5.RELEASE</version> </parent> </project>
-
3.web项目,需要引入web启动器依赖,版本由父工程管理
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies>
如何启动SpringBoot项目
1560136198438.pngpackage com.neuedu;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class BootApplication {
public static void main(String[] args) {
SpringApplication.run(BootApplication.class);
}
}
在application.yml中指定启动端口(默认8080)
# 指定启动端口
server:
port: 8888
启动启动类
1560137037487.png这个启动类要想生效,它的路径必须在所有子包的父级路径中
SpringBoot中有自动扫描,是以启动类@SpringBootApplication
为起点向下扫描所有子包,所以直接就可以写web层,愉快的开发了
package com.neuedu.web;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class HelloController {
@RequestMapping("hello")
@ResponseBody
public String hello(){
return "hello,StringBoot!";
}
}
1560137180169.png
简单测试,效果完美!
整合数据库连接池,mybatis,和事务
引入mybatis启动器和mysql依赖
<dependencies>
<!--web启动器-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.4</version>
</dependency>
<!--mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.39</version>
</dependency>
<!-- mybatis启动器 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
</dependencies>
application.yml
# 数据库连接参数
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/java2demo?useUnicode=true&characterEncoding=utf8
username: root
password: root
# 数据库连接池
hikari:
maximum-pool-size: 30 # 最大连接数
minimum-idle: 10 # 最小连接数
idle-timeout: 60000 # 超时时间
# 指定mapper文件路径 , 配置包中类别名
mybatis:
mapper-locations: classpath:mappers/*.xml
type-aliases-package: com.neuedu.pojo
# 指定日志打印级别,输出SQL语句
logging:
level:
com.neuedu.mapper: debug
需要注意的是,mapper层要想被正确装配,需要在mapper层接口上添加@Mapper
注解或者在启动上添加@MapperScan
注解完成扫描
@SpringBootApplication
@MapperScan("com.neuedu.mapper") // 指定mapper包
public class BootApplication {
public static void main(String[] args) {
SpringApplication.run(BootApplication.class);
}
}
完整展示
pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.zpwd</groupId>
<artifactId>springBootDemo1</artifactId>
<version>1.0-SNAPSHOT</version>
<!-- 引入父工程,当前最新版本2.1.5 -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.5.RELEASE</version>
</parent>
<dependencies>
<!--web启动器-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.4</version>
</dependency>
<!--mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.39</version>
</dependency>
<!-- mybatis启动器 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<!--redis-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!--fastjson-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.47</version>
</dependency>
</dependencies>
</project>
application.yml
# 指定启动端口
server:
port: 8080
# 数据库连接参数
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/zpwd?useUnicode=true&characterEncoding=utf8
username : root
password : root
# 数据库连接池
hikari:
idle-timeout: 6000
minimum-idle: 1
maximum-pool-size: 30
#集成redis
redis:
host: 127.0.0.1
port: 6379
password: 123456
jedis:
pool:
max-idle: 300
max-wait: 1000
max-active: 8
min-idle: 10
#指定mapper文件路径
mybatis:
mapper-locations: classpath:mappers/*.xml
type-aliases-package: com.zpwd.pojo
#指定日志打印级别
logging:
level:
com.zpwd.mapper: debug
BootApplication
package com.zpwd;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication // 快速启动
@MapperScan("com.zpwd.mapper") // 扫描mapper文件
public class BootApplication {
public static void main(String[] args) {
SpringApplication.run( BootApplication.class );
}
}
Controller
@CrossOrigin // 前后端分离
@Controller // 托管
@RequestMapping("user") // 类映射
public class UserController {
@Autowired // 自动装配
UserinfoService userinfoService;
@RequestMapping("findById") // 方法映射
@ResponseBody // 响应ajax
public Userinfo findById(@RequestParam("id") Long id){
return userinfoService.findById( id );
}
}
serviceImpl
@Service
public class UserinfoServiceImpl implements UserinfoService {
@Autowired // 装配redis
StringRedisTemplate stringRedisTemplate;
@Autowired
UserinfoMapper userinfoMapper;
@Override
public Userinfo findById(Long id) {
stringRedisTemplate.opsForValue().set("userinfo","hello");
return userinfoMapper.findById( id );
}
}
注意
mapper.xml文件在resources文件夹下创建
SpringBoot脚手架
1560153689533.png下一步后选择对应的依赖,自动生成下图。
image.png
还记得静态资源放行吗
resources下只要是static、resources、templates文件夹下的文件,springboot自动会对其放行。不过目前流行的前后端分离项目,该处用处不大。
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