2.1创建spring boot项目项目
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2.2pom.xml文件介绍
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<!-- 描述这个POM文件是遵从哪个版本的项目描述符-->
<modelVersion>4.0.0</modelVersion>
<!--指向当前工程的父工程的gav坐标-->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<!--当前工程的gav坐标-->
<!--一般是项目的java文件所在的包名,其确定了在项目install的时候的打包路径-->
<groupId>com.bjpowernode.springboot</groupId>
<artifactId>001-springboot-fist</artifactId>
<!--配和groupId,artifactId使用,其确定了被打jar包的所属版本文件夹名,同时也会加在jar包文件名上-->
<version>1.0.0</version>
<!--jar包的名称和version共同组成包名-->
<name>001-springboot-fist</name>
<!--项目包的简单描述-->
<description>Demo project for Spring Boot</description>
<!--指定java编译的版本-->
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!--SpringBoot框架web项目起步依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--SpringBoot框架测试起步依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vinteage</groupId>
<artifactId>junit-vinteage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<!--SpringBoot项目打包编译的插件-->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2.3目录结构介绍
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注意:SpringBoot项目代码必须放在Application类所在的同级目录或下级目录中
2.4使用SpringBoot框架继承SpringMVC
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即只要创建了SpringBoot框架,则就集成了SpringMVC
验证:
编写代码:
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运行:
启动项目入口类访问工程:
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@Controller(用在控制器的类上面的)
放在控制器(处理器)类的上面,创建控制器对象的,能够接受用户提交的参数,显示请求的处理结果。
@RequestMapping
在Spring MVC 中使用 @RequestMapping 来映射请求,也就是通过它来指定控制器可以处理哪些URL请求,相当于Servlet中在web.xml中配置的映射作用一致。
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Mapping
public @interface RequestMapping {
String name() default "";
@AliasFor("path")
String[] value() default {};
@AliasFor("value")
String[] path() default {};
RequestMethod[] method() default {};
String[] params() default {};
String[] headers() default {};
String[] consumes() default {};
String[] produces() default {};
}
@RequestMapping 中的 value 和 path 属性(这两个属性作用相同,可以互换,如果仅有这一个属性,则可以省略)
@RequestMapping 中的 method 主要用来定义接收浏览器发来的何种请求。
@RequestMapping 的 params 属性表示请求参数,也就是追加在URL上的键值对,多个请求参数以&隔开。
@RequestMapping 的 headers 属性,该属性表示请求头
学习资料:https://blog.csdn.net/renanrenan/article/details/84654362/
@ResponseBody
@ResponseBody的作用其实是将java对象转为json格式的数据。
第一种用法,方法头部;第二种用法,方法修饰符后。效果一样。
学习资料:https://jingyan.baidu.com/article/a24b33cd3c841319fe002b8a.html
2.5使用SpringBoot的核心配置文件application.properties
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在application.properties设置内嵌Tomcat端口号和上下文根
#设置内嵌Tomcat端口号
server.port=8081
#设置上下文跟根
server.servlet.context-path=/springboot
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2.6SpringBoot框架的核心配置文件application.properties和application.yml(或者application.yaml)同时存在时
//程序代码
@Controller
public class IndexController {
@RequestMapping(value = "/say")
public @ResponseBody Object say(String message){
return "Say Hello"+message;
}
}
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#设置端口号与上下文根
server:
port: 8082
servlet:
context-path: /
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2.7SpringBoot的核心配置文件application.yml或者application.yaml
//程序代码
@Controller
public class IndexController {
@RequestMapping(value = "/say")
public @ResponseBody String say(){
return "Hello SpringBoot";
}
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小结:application.properties和application.yml文件都存在时,优先执行application.properties文件
maven编译找依赖时:
->本地仓库->找到->使用
->本地仓库->镜像仓库->找到->本地仓库->使用
->本地仓库->中央仓库(在国外)->找到->本地仓库->使用<mirrors> //镜像仓库阿里云 <mirror> <id> nexus-aliyum</id> <mirrorof>*</mirrorof> <name>Nexus aliyun</name> <url> http://maven.aliyun.com/nexus/content/groups/public</url> </mirror> </mirrors>
2.8多环境下核心配置文件(.properties)的使用
工作中开发的化境有哪些:开发环境、测试环境、准生产环境、生产环境
//程序代码
@Controller
public class IndexController {
@RequestMapping(value = "/say")
public @ResponseBody String say(){
return "Hello SpringBoot!";
}
}
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2.9多环境下核心配置文件(.yml或.yaml)的使用
//程序代码
@Controller
public class IndexController {
@RequestMapping(value = "/say")
public @ResponseBody String say(){
return "Hello SpringBoot!";
}
}
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2.10SpringBoot在核心配置文件application.properties自定义配置
//程序代码
@Controller
public class IndexController {
@Value("${school.name}")
private String schoolName;
@Value("${websit}")
private String websit;
@RequestMapping(value = "/say")
public @ResponseBody String say(){
return "Hello World!"+schoolName+":"+websit;
}
}
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运行结果:
Tomcat started on port(s): 8081 (http) with context path ''
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@Value:简单类型的属性赋值(需要先创建对象注解)
属性:value是String类型的,表示简单类型的属性值
位置:1.在属性定义的上面,无需set方法(推荐使用)
@Value给对象赋值.png
2.在set方法的上面
@Value给对象赋值2.png
2.11SpringBoot在核心配置文件将自定义配置映射到对象
要求:前缀必须是统一的
appllication.properties文件👇
#上下文根和端口号 server.port=8080 server.servlet.context-path=/ school.name=bjpowernode school.websit=http://www.bjpowernode.com abc.name=abc abc.websit=http://www.abc.com
School对象👇
package com.bjpowernode.springboot.config; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component; //将类定义为一个bean的注解,将此类交给spring容器进行管理 @Component //表示使用配置文件中前缀为school的属性的值初始化该bean定义产生的bean实例的同名属性 @ConfigurationProperties(prefix = "school") public class School { private String name; private String websit; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getWebsit() { return websit; } public void setWebsit(String websit) { this.websit = websit; } }
Controller控制器👇
package com.bjpowernode.springboot.web; import com.bjpowernode.springboot.config.School; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; @Controller public class IndexController { @Autowired private School school; @RequestMapping(value = "/say") public @ResponseBody String say(){ return "school.name="+school.getName()+",school.websit="+school.getWebsit(); } }
运行结果:
Tomcat started on port(s): 8080 (http) with context path '
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@Autowired引用类型的属性赋值(需要先创建对象注解)
spring框架提供的注解,实现引用类型的赋值,使用的是自动注入原理,支持byName,byType
@Autowired的required属性
required是一个Boolean类型的,默认true
required=true:表示引用类型赋值失败,程序报错,终止执行。
required=false:表示引用类型赋值失败,程序正常执行,引用类型为null。默认使用byType自动注入:
位置:
1)在属性定义的上面,无需set方法(推荐使用)
@Autowired在属性定义上.png
2)在set方法的上面
@Autowired在set方法上.png
使用byName方式:
1)在属性上面加入@Autowired2)在属性上面加入@Qualifier(value="bean的id"):
表示使用指定名称的bean完成赋值。![]()
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@Component表示将类定义为一个bean的注解,将此类交给spring容器进行管理
@ConfigurationProperties(配置属性注解)表示使用配置文件中前缀为school的属性的值初始化该bean定义产生的bean实例的同名属性@Component @ConfigurationProperties(prefix = "school") public class School { private String name; private String websit; //省略getter/setter方法 }
<dependencies>
<!--解决使用@ConfigurationProperties注解出现的警告-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
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2.12SpringBoot集成jsp
①创建文件夹存放jsp
:创建一个普通文件夹webapp
②设置web资源文件夹
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③添加依赖
<dependencies>
<!--引用SpringBoot内嵌Tomcat队jsp的解析依赖,不添加解析不了-->
<!--仅仅只是展示jsp页面,只添加以下一个依赖-->
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
</dependency>
</dependencies>
④指定编译jsp的路径
<build>
<!--
SpringBoot项目默认推荐使用的前端引擎是thymeleaf
现在我们要使用SpringBoot集成jsp,手动指定jsp最后编译的路径
而且SpringBoot集成jsp编译jsp的路径是SpringBoot规定好的位置
META-INF/resources
-->
<resources>
<resource>
<!--源文件夹-->
<directory>src/main/webapp</directory>
<!--指定编译到META-INF/resources-->
<targetPath>META-INF/resources</targetPath>
<!--指定源文件夹中的哪个资源要进行编译-->
<includes>
<include>*.*</include>
</includes>
</resource>
</resources>
</build>
⑤在application.properties中配置视图解析器
#配置视图解析器
spring.mvc.view.prefix=/
spring.mvc.view.suffix=.jsp
⑥编写代码
控制器👇
package com.bjpowernode.springboot.web; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.servlet.ModelAndView; @Controller public class IndexController { @RequestMapping("/say") public ModelAndView say(){ ModelAndView modelAndView=new ModelAndView(); >modelAndView.addObject("message","Hello,SpringBoot"); modelAndView.setViewName("say"); return modelAndView; } }
jsp页面(web资源文件夹内)👇
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <h1>${message}</h1> </body> </html>
运行结果:
Tomcat started on port(s): 8080 (http) with context path ''
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ModelAndView
使用ModelAndView类用来存储处理完后的结果数据,以及显示该数据的视图。业务处理器调用模型层处理完用户请求后,把结果数据存储在该类的model属性中,把要返回的视图信息存储在该类的view属性中,然后让该ModelAndView返回该Spring MVC框架。框架通过调用配置文件中定义的视图解析器,对该对象进行解析,最后把结果数据显示在指定的页面上。
具体作用:
1. 设置转向地址(返回指定页面)
ModelAndView构造方法可以指定返回的页面名称,ModelAndView view = new ModelAndView("path:ok");
也可以通过setViewName()方法跳转到指定的页面 。2.返回所需数值
用于传递控制方法处理结果数据到结果页面,也就是说我们把结果页面上需要的数据放到ModelAndView对象中即可。
addObject()设置需要返回的值。
addAttribute(String key,Object value);
2.13手动创建SpringBoot工程
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项目实例
pom.xml👇
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.12-SNAPSHOT</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
resources-application.yml👇
spring:
profiles:
active: dev
resources-application-dev-yml👇
server:
port: 8081
spring:
datasource:
username: root
password: abc1234.
url: jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
mapper-locations: classpath:mappring/*Mapper.xml
type-aliases-package: com.example.entity
#showSql
logging:
level:
com:
example:
mapper : debug
entity-Admin👇
package com.example.entity;
public class Admin {
private Integer adminId;
private String adminPwd;
public Integer getAdminId() {
return adminId;
}
public void setAdminId(Integer adminId) {
this.adminId = adminId;
}
public String getAdminPwd() {
return adminPwd;
}
public void setAdminPwd(String adminPwd) {
this.adminPwd = adminPwd;
}
@Override
public String toString() {
return "Admin{" +
"adminId=" + adminId +
", adminPwd='" + adminPwd + '\'' +
'}';
}
}
mapper-AdminMapper👇
package com.example.mapper;
import com.example.entity.Admin;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository
public interface AdminMapper {
/*根据adminId查询数据*/
public Admin selectById(@Param("adminId") int adminId);
/*查询所有数据*/
public List<Admin> selectAll();
/*添加数据*/
public int insertAdmin(@Param("adminId") int adminId,@Param("adminPwd") String adminPwd);
/*根据adminId删除数据*/
public int deleteById(@Param("adminId") int adminId);
/*根据adminId修改密码*/
public int updateById(@Param("adminId") int adminId,@Param("adminPwd") String adminPwd);
}
resources-mapping-AdminMapper.xml👇
<?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.example.mapper.AdminMapper">
<resultMap id="BaseResultMap" type="com.example.entity.Admin">
<result column="admin_id" jdbcType="INTEGER" property="adminId" />
<result column="admin_pwd" jdbcType="VARCHAR" property="adminPwd" />
</resultMap>
<select id="selectById" resultMap="BaseResultMap">
select * from admin where admin_id = #{adminId}
</select>
<select id="selectAll" resultMap="BaseResultMap">
select * from admin
</select>
<insert id="insertAdmin">
insert into admin values (#{adminId},#{adminPwd});
</insert>
<delete id="deleteById">
delete from admin where admin_id = #{adminId}
</delete>
<update id="updateById">
update admin set admin_pwd = #{adminPwd} where admin_id = #{adminId}
</update>
</mapper>
service-AdminService👇
package com.example.service;
import com.example.entity.Admin;
import com.example.mapper.AdminMapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class AdminService {
@Autowired
AdminMapper adminMapper;
/*查询所有数据*/
public Admin selectById(int adminId){
return adminMapper.selectById(adminId);
}
/*public int selectByIdPwd(String username,String password){
return adminMapper.selectByIdPwd(username,password);
}*/
/*添加数据*/
public List<Admin> selectAll(){
return adminMapper.selectAll();
}
/*public int insertUser(){
return adminMapper.insertUser();
}*/
/*添加数据*/
public int insertAdmin(int adminId,String adminPwd){
return adminMapper.insertAdmin(adminId,adminPwd);
}
/*根据adminId删除数据*/
public int deleteById(int adminId){
return adminMapper.deleteById(adminId);
}
/*根据adminId修改密码*/
public int updateById(int adminId,String adminPwd){
return adminMapper.updateById(adminId,adminPwd);
}
}
controller-AdminController👇
package com.example.controller;
import com.example.entity.Admin;
import com.example.service.AdminService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
@RequestMapping("/adminController")
public class AdminController {
@Autowired
private AdminService adminService;
/*根据adminId查询数据*/
@RequestMapping("/selectById/{adminId}")
public @ResponseBody Admin selectById(@PathVariable int adminId){
Admin sel = adminService.selectById(adminId);
System.out.println(sel);
return sel;
}
/*查询所有数据*/
@RequestMapping("/selectAll")
public @ResponseBody List<Admin> selectAll(){
List<Admin> sel = adminService.selectAll();
System.out.println(sel);
return sel;
}
/*添加数据*/
@RequestMapping("/insertAdmin/{adminId}&{adminPwd}")
public @ResponseBody int insertAdmin(@PathVariable int adminId,@PathVariable String adminPwd){
int i = adminService.insertAdmin(adminId, adminPwd);
System.out.println("成功添加"+i+"条编号为"+adminId+"的数据");
return adminId;
}
/*根据adminId删除数据*/
@RequestMapping("/deleteById/{adminId}")
public @ResponseBody int deleteById(@PathVariable int adminId){
int i = adminService.deleteById(adminId);
System.out.println("成功删除"+i+"条编号为"+adminId+"的数据");
return adminId;
}
/*根据adminId修改密码*/
@RequestMapping("/updateById/{adminId},{adminPwd}")
public @ResponseBody int updateById(@PathVariable int adminId,@PathVariable String adminPwd){
adminService.updateById(adminId, adminPwd);
System.out.println("成功修改编号为"+adminId+"的数据");
return adminId;
}
}
启动入口类:java.com.exampl.DemoApplication👇
package com.example;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("com.example.mapper")//扫描的mapper
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
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