文章目录
概述
springBoot是Spring项目中的一个子工程,与我们所熟知的Spring-framework 同属于spring的产品,使用springboot,可以让我们快速的构建庞大的spring项目(包括web 持久化),并且尽可能的减少一切xml配置,做到开箱即用,迅速上手,让我们关注业务而非配置
为什么要使用SpringBoot?
它的出现解决了传统spring项目以下的问题:
- 配置负责繁多
每一个组件集成spring都需要编写对应配置文件,比如appplicationContext-xxx.xml
- 混乱的依赖管理
在spirng中想集成对应组件时,需要导入N多的pom,并且还有考虑版本。
我们使用SpringBoot创建java应用,只需填写很少配置和依赖就能快速搭建,并使用java –jar 启动它,就能得到一个生产级别的web工程。非常方便
入门
首先创建好一个maven项目,然后在pom.xml中加入依赖
<!-- 指定SpringBoot的版本 -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.5.RELEASE</version>
</parent>
<!-- 导入SpringBoot的Jar包-->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
然后编写一个Controller类
package com.ifueen.hello;
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 SpringBoot";
}
}
最后编写一个配置类来启动
package com.ifueen.hello;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
* SpingBoot的引导类
*/
@SpringBootApplication
public class HelloSpringBoot {
public static void main(String[] args){
//加载这个控制器
SpringApplication.run(HelloSpringBoot.class);
}
}
启动这个配置类,然后在浏览器中输入localhost:8080/hello就可以看到效果了
项目结构
一个SpingBoot的基本项目结构如下
src
--main
--java
--resources
--static //静态资源目录
--templates //模板页面目录,如:jsp ,ftl
--application.properties/application.yml //默认配置文件
打包
pom.xml中导入打包插件
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
打包完成后在cmd中运行命令
java -jar xxx.jar
SpringBoot读取配置
使用@Value标签
配置文件
# 设置端口
server.port=5050
绑定配置的对象
//读取端口
@Value("${server.port}")
private String port;
使用@ConfigurationProperties
配置文件
#配置数据库
db.driverClassName=com.mysql.jdbc.Driver
db.url=jdbc:mysql:///rpms?useUnicode=true&characterEncoding=utf-8
db.username=root
db.password=123456
新建一个类来存放读取的配置
package com.ifueen.hello.read_properties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
/**
* 读取配置文件的类
*/
@Component
@ConfigurationProperties(prefix = "db")
public class DbProperties {
private String driverClassName;
private String url;
private String username;
private String password;
@Override
public String toString() {
return "DbProperties{" +
"driverClassName='" + driverClassName + '\'' +
", url='" + url + '\'' +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
public String getDriverClassName() {
return driverClassName;
}
public void setDriverClassName(String driverClassName) {
this.driverClassName = driverClassName;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
多环境切换
方式一
spring:
profiles:
active: test #激活(选择)环境test
---
spring:
profiles: dev #指定环境名字dev
server:
port: 9999
---
spring:
profiles: test #指定环境名字test
server:
port: 8888
方式二
通过配置文件的名字来识别环境
application-dev.yml
server:
port: 9999
application-test.yml
server:
port: 8888
application.yml
spring:
profiles:
active: test
#根据文件名字配置 application-dev.properties
日志使用
基本使用
//日志
private static Logger log = LoggerFactory.getLogger(HelloController.class);
log.debug(connection.toString());
log.error("错误信息s");
log.warn("警告信息");
log.info("详细信息");
配置日志
# 配置日志
logging.level.root=info
logging.level.com.ifueen.hello=trace
logging.file=mylog.log
logging.pattern.console=%white(%d{yyyy-MM-dd HH:mm:ss}) %highlight(%lsn) %green([%thread]) %highlight(%-5level) %boldMagenta(%logger{10}) - %cyan(%msg%n)
logging.pattern.file=%white(%d{yyyy-MM-dd HH:mm:ss}) %highlight(%lsn) %green([%thread]) %highlight(%-5level) %boldMagenta(%logger{10}) - %cyan(%msg%n)
指定配置文件配置logback-spring.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="5 seconds" debug="false">
<!-- 定义输出日志的格式和位置 -->
<property name="SpringBoot_Log" value="%d{HH:mm:ss.SSS} %contextName [%thread] %-5level %logger{36} - %msg%n" />
<!--输出到控制台-->
<appender name="console" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>${SpringBoot_Log}</pattern>
<charset>UTF-8</charset>
</encoder>
</appender>
<!--输出到文件-->
<appender name="file" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>logs/springboot.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
<fileNamePattern>logs/springboot-%d{yyyyMMdd}-%i.log.gz</fileNamePattern>
<!-- 单个文件最大值 -->
<maxFileSize>5KB</maxFileSize>
<!-- 保留历史 -->
<maxHistory>30</maxHistory>
<!-- 总文件大小 -->
<totalSizeCap>1GB</totalSizeCap>
</rollingPolicy>
<encoder>
<pattern>${SpringBoot_Log}</pattern>
<charset>UTF-8</charset>
</encoder>
</appender>
<!-- 输出级别 -->
<root level="info">
<appender-ref ref="console" />
<appender-ref ref="file" />
</root>
<logger name="com.ifueen" level="trace" additivity="false">
<appender-ref ref="console"/>
<appender-ref ref="file"/>
</logger>
</configuration>
SpringBoot集成Thymeleaf
导入依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
创建模板 resources/templates/hello.html
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>欢迎奥</title>
<script src="webjars/jquery/3.4.1/jquery.js"></script>
</head>
<script>
alert($)
</script>
<body>
<h1>让我康康</h1>
<div th:text="${msg}"></div>
</body>
</html>
Controller配置
@RequestMapping("/hello")
public String home(Model model){
model.addAttribute("msg","我们不能失去信仰");
return "hello";
}
Thymeleaf的自动配置原理
@EnableAutoConfiguration 开启自动配置功能,通过一个AutoConfigurationImportSelector导入选择器去扫描 spring-boot-autoconfigure-2.0.5.RELEASE.jar 自动配置包下面的 spring.factories 文件中的很多很多的自动配置的类
而:ThymeleafAutoConfiguration 是的Thymeleaf的自动配置 ,在这个自动配置类里面通过一个ThymeleafProperties去读取配置文件中的配置(也有默认配置) ,来自动配置Thymeleaf,比如Thymeleaf的视图解析器的自动配置如下:
@Bean
@ConditionalOnMissingBean(name = "thymeleafViewResolver")
public ThymeleafViewResolver thymeleafViewResolver() {
ThymeleafViewResolver resolver = new ThymeleafViewResolver();
...
return resolver;
}
静态资源
1.静态资源目录
resource/static
2.webjars
导入jquery依赖 ( http://www.webjars.org/)
<dependency>
<groupId>org.webjars</groupId>
<artifactId>jquery</artifactId>
<version>3.4.1</version>
</dependency>
导入jquery的js
<script src="/webjars/jquery/3.4.1/jquery.js"></script>
SpringBoot中的MVC配置
1.配置拦截器
定义拦截器
package com.ifueen.hello;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 拦截器
*/
@Component
public class LoginCheckInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("拦截");
return true;
}
}
注册拦截器
package com.ifueen.hello;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
/**
* SpringMVC的配置
*/
@Configuration
public class MyMvcConfig implements WebMvcConfigurer {
@Autowired
private LoginCheckInterceptor loginCheckInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
//拦截所有
registry.addInterceptor(loginCheckInterceptor).addPathPatterns("/**");
}
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/xx").setViewName("xx.html");
}
}
2.添加视图控制器
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/xx").setViewName("hello2.html");
}
当访问/xx 定位到 templates/hello2.html
集成DataSource(连接池)
1.导入依赖
<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.20</version>
</dependency>
<!-- mysql 数据库驱动. -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
手动配置方式
手动配置四个属性
db.driverClassName=com.mysql.jdbc.Driver
db.url=jdbc:mysql:///rpms?useUnicode=true&characterEncoding=utf-8
db.username=root
db.password=123456
@Bean
@ConfigurationProperties(prefix = "db")
public DataSource dataSource(){
DruidDataSource dataSource = new DruidDataSource();
return dataSource ;
}
自动配置方式 (重点)
# 配置datasource -- 自动配置
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql:///rpms?useUnicode=true&characterEncoding=utf-8
spring.datasource.username=root
spring.datasource.password=123456