Spring Boot
Spring Boot 是一个快速开发框架，可以迅速搭建出一套基于 Spring 框架体系的应用，是 Spring Cloud 的基础。
Spring Boot 开启了各种自动装配，从而简化代码的开发，不需要编写各种配置文件，只需要引入相关依赖就可以迅速搭建一个应用。
- 特点
1、不需要 web.xml
2、不需要 springmvc.xml
3、不需要 tomcat，Spring Boot 内嵌了 tomcat
4、不需要配置 JSON 解析，支持 REST 架构
5、个性化配置非常简单
- 如何使用
1、创建 Maven 工程，导入相关依赖。
org.springframework.boot
spring-boot-starter-parent
2.0.7.RELEASE
org.springframework.boot
spring-boot-starter-web
org.projectlombok
lombok
1.18.6
provided
2、创建 Student 实体类
package com.southwind.entity;
import lombok.Data;
@Data
public class Student {
private long id;
private String name;
private int age;
}
3、StudentRepository
package com.southwind.repository;
import com.southwind.entity.Student;
import java.util.Collection;
public interface StudentRepository {
public Collection findAll();
public Student findById(long id);
public void saveOrUpdate(Student student);
public void deleteById(long id);
}
4、StudentRepositoryImpl
package com.southwind.repository.impl;
import com.southwind.entity.Student;
import com.southwind.repository.StudentRepository;
import org.springframework.stereotype.Repository;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
@Repository
public class StudentRepositoryImpl implements StudentRepository {
private static Map studentMap;
static{
studentMap = new HashMap<>();
studentMap.put(1L,new Student(1L,"张三",22));
studentMap.put(2L,new Student(2L,"李四",23));
studentMap.put(3L,new Student(3L,"王五",24));
}
@Override
public Collection findAll() {
return studentMap.values();
}
@Override
public Student findById(long id) {
return studentMap.get(id);
}
@Override
public void saveOrUpdate(Student student) {
studentMap.put(student.getId(),student);
}
@Override
public void deleteById(long id) {
studentMap.remove(id);
}
}
5、StudentHandler
package com.southwind.controller;
import com.southwind.entity.Student;
import com.southwind.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.Collection;
@RestController
@RequestMapping("/student")
public class StudentHandler {
@Autowired
private StudentRepository studentRepository;
@GetMapping("/findAll")
public Collection findAll(){
return studentRepository.findAll();
}
@GetMapping("/findById/{id}")
public Student findById(@PathVariable("id") long id){
return studentRepository.findById(id);
}
@PostMapping("/save")
public void save(@RequestBody Student student){
studentRepository.saveOrUpdate(student);
}
@PutMapping("/update")
public void update(@RequestBody Student student){
studentRepository.saveOrUpdate(student);
}
@DeleteMapping("/deleteById/{id}")
public void deleteById(@PathVariable("id") long id){
studentRepository.deleteById(id);
}
}
6、application.yml
server:
port: 9090
7、启动类
package com.southwind;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class,args);
}
}
@SpringBootApplication 表示当前类是 Spring Boot 的入口，Application 类的存放位置必须是其他相关业务类的存放位置的父级。
Spring Boot 整合 JSP
- pom.xml
org.springframework.boot
spring-boot-starter-parent
2.0.7.RELEASE
org.springframework.boot
spring-boot-starter-web
org.springframework.boot
spring-boot-starter-tomcat
org.apache.tomcat.embed
tomcat-embed-jasper
jstl
jstl
1.2
org.projectlombok
lombok
1.18.6
provided
- 创建配置文件 application.yml
server:
port: 8181
spring:
mvc:
view:
prefix: /
suffix: .jsp
- 创建 Handler
package com.southwind.controller;
import com.southwind.entity.Student;
import com.southwind.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
@RequestMapping("/hello")
public class HelloHandler {
@Autowired
private StudentRepository studentRepository;
@GetMapping("/index")
public ModelAndView index(){
ModelAndView modelAndView = new ModelAndView();
modelAndView.setViewName("index");
modelAndView.addObject("list",studentRepository.findAll());
return modelAndView;
}
@GetMapping("/deleteById/{id}")
public String deleteById(@PathVariable("id") long id){
studentRepository.deleteById(id);
return "redirect:/hello/index";
}
@PostMapping("/save")
public String save(Student student){
studentRepository.saveOrUpdate(student);
return "redirect:/hello/index";
}
@PostMapping("/update")
public String update(Student student){
studentRepository.saveOrUpdate(student);
return "redirect:/hello/index";
}
@GetMapping("/findById/{id}")
public ModelAndView findById(@PathVariable("id") long id){
ModelAndView modelAndView = new ModelAndView();
modelAndView.setViewName("update");
modelAndView.addObject("student",studentRepository.findById(id));
return modelAndView;
}
}
- JSP
<%--
Created by IntelliJ IDEA.
User: southwind
Date: 2019-03-21
Time: 12:02
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored="false" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
Title
学生信息
学生编号
学生姓名
学生年龄
操作
${student.id}
${student.name}
${student.age}
修改
删除
添加学生
<%--
Created by IntelliJ IDEA.
User: southwind
Date: 2019-03-21
Time: 12:09
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
Title
<%--
Created by IntelliJ IDEA.
User: southwind
Date: 2019-03-21
Time: 12:09
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
Title
Spring Boot HTML
Spring Boot 可以结合 Thymeleaf 模版来整合 HTML，使用原生的 HTML 作为视图。
Thymeleaf 模版是面向 Web 和独立环境的 Java 模版引擎，能够处理 HTML、XML、JavaScript、CSS 等。
- pom.xml
org.springframework.boot
spring-boot-starter-parent
2.0.7.RELEASE
org.springframework.boot
spring-boot-starter-web
org.projectlombok
lombok
1.18.6
provided
org.springframework.boot
spring-boot-starter-thymeleaf
- appliction.yml
server:
port: 9090
spring:
thymeleaf:
prefix: classpath:/templates/
suffix: .html
mode: HTML5
encoding: UTF-8
- Handler
package com.southwind.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
@RequestMapping("/index")
public class IndexHandler {
@GetMapping("/index")
public String index(){
System.out.println("index...");
return "index";
}
}
- HTML
Title
Hello World
如果希望客户端可以直接访问 HTML 资源，将这些资源放置在 static 路径下即可，否则必须通过 Handler 的后台映射才可以访问静态资源。
Thymeleaf 常用语法
- 赋值、拼接
@GetMapping("/index2")
public String index2(Map map){
map.put("name","张三");
return "index";
}
- 条件判断：if/unless
th:if 表示条件成立时显示内容，th:unless 表示条件不成立时显示内容
@GetMapping("/if")
public String index3(Map map){
map.put("flag",true);
return "index";
}
- 循环
@GetMapping("/index")
public String index(Model model){
System.out.println("index...");
List list = new ArrayList<>();
list.add(new Student(1L,"张三",22));
list.add(new Student(2L,"李四",23));
list.add(new Student(3L,"王五",24));
model.addAttribute("list",list);
return "index";
}
index
count
学生ID
学生姓名
学生年龄
stat 是状态变量，属性：
- index 集合中元素的index（从0开始）
- count 集合中元素的count（从1开始）
- size 集合的大小
- current 当前迭代变量
- even/odd 当前迭代是否为偶数/奇数（从0开始计算）
- first 当前迭代的元素是否是第一个
- last 当前迭代的元素是否是最后一个
- URL
Thymeleaf 对于 URL 的处理是通过 @{...} 进行处理，结合 th:href 、th:src
Hello World
跳转
跳转2
![]()
- 三元运算
@GetMapping("/eq")
public String eq(Model model){
model.addAttribute("age",30);
return "test";
}
- gt great than 大于
- ge great equal 大于等于
- eq equal 等于
- lt less than 小于
- le less equal 小于等于
- ne not equal 不等于
- switch
@GetMapping("/switch")
public String switchTest(Model model){
model.addAttribute("gender","女");
return "test";
}
女
男
未知
- 基本对象
-
#ctx：上下文对象 -
#vars：上下文变量 -
#locale：区域对象 -
#request：HttpServletRequest 对象 -
#response：HttpServletResponse 对象 -
#session：HttpSession 对象 -
#servletContext：ServletContext 对象
-
@GetMapping("/object")
public String object(HttpServletRequest request){
request.setAttribute("request","request对象");
request.getSession().setAttribute("session","session对象");
return "test";
}
- 内嵌对象
可以直接通过 # 访问。
1、dates：java.util.Date 的功能方法
2、calendars：java.util.Calendar 的功能方法
3、numbers：格式化数字
4、strings：java.lang.String 的功能方法
5、objects：Object 的功能方法
6、bools：对布尔求值的方法
7、arrays：操作数组的功能方法
8、lists：操作集合的功能方法
9、sets：操作集合的功能方法
10、maps：操作集合的功能方法
@GetMapping("/util")
public String util(Model model){
model.addAttribute("name","zhangsan");
model.addAttribute("users",new ArrayList<>());
model.addAttribute("count",22);
model.addAttribute("date",new Date());
return "test";
}
Spring Boot 数据校验
package com.southwind.entity;
import lombok.Data;
import org.hibernate.validator.constraints.Length;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
@Data
public class User {
@NotNull(message = "id不能为空")
private Long id;
@NotEmpty(message = "姓名不能为空")
@Length(min = 2,message = "姓名长度不能小于2位")
private String name;
@Min(value = 16,message = "年龄必须大于16岁")
private int age;
}
@GetMapping("/validator")
public void validatorUser(@Valid User user,BindingResult bindingResult){
System.out.println(user);
if(bindingResult.hasErrors()){
List list = bindingResult.getAllErrors();
for(ObjectError objectError:list){
System.out.println(objectError.getCode()+"-"+objectError.getDefaultMessage());
}
}
}
Spring Boot 整合 JDBC
- pom.xml
org.springframework.boot
spring-boot-starter-jdbc
mysql
mysql-connector-java
8.0.11
- application.yml
server:
port: 9090
spring:
thymeleaf:
prefix: classpath:/templates/
suffix: .html
mode: HTML5
encoding: UTF-8
datasource:
url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8
username: root
password: root
driver-class-name: com.mysql.cj.jdbc.Driver
- User
package com.southwind.entity;
import lombok.Data;
import org.hibernate.validator.constraints.Length;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
@Data
public class User {
@NotNull(message = "id不能为空")
private Long id;
@NotEmpty(message = "姓名不能为空")
@Length(min = 2,message = "姓名长度不能小于2位")
private String name;
@Min(value = 60,message = "成绩必须大于60分")
private double score;
}
- UserRepository
package com.southwind.repository;
import com.southwind.entity.User;
import java.util.List;
public interface UserRepository {
public List findAll();
public User findById(long id);
public void save(User user);
public void update(User user);
public void deleteById(long id);
}
- UserRepositoryImpl
package com.southwind.repository.impl;
import com.southwind.entity.User;
import com.southwind.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository
public class UserRepositoryImpl implements UserRepository {
@Autowired
private JdbcTemplate jdbcTemplate;
@Override
public List findAll() {
return jdbcTemplate.query("select * from user",new BeanPropertyRowMapper<>(User.class));
}
@Override
public User findById(long id) {
return jdbcTemplate.queryForObject("select * from user where id = ?",new Object[]{id},new BeanPropertyRowMapper<>(User.class));
}
@Override
public void save(User user) {
jdbcTemplate.update("insert into user(name,score) values(?,?)",user.getName(),user.getScore());
}
@Override
public void update(User user) {
jdbcTemplate.update("update user set name = ?,score = ? where id = ?",user.getName(),user.getScore(),user.getId());
}
@Override
public void deleteById(long id) {
jdbcTemplate.update("delete from user where id = ?",id);
}
}
- Handler
package com.southwind.controller;
import com.southwind.entity.User;
import com.southwind.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RestController
@RequestMapping("/user")
public class UserHandler {
@Autowired
private UserRepository userRepository;
@GetMapping("/findAll")
public List findAll(){
return userRepository.findAll();
}
@GetMapping("/findById/{id}")
public User findById(@PathVariable("id") long id){
return userRepository.findById(id);
}
@PostMapping("/save")
public void save(@RequestBody User user){
userRepository.save(user);
}
@PutMapping("/update")
public void update(@RequestBody User user){
userRepository.update(user);
}
@DeleteMapping("/deleteById/{id}")
public void deleteById(@PathVariable("id") long id){
userRepository.deleteById(id);
}
}
Spring Boot 整合 MyBatis
- pom.xml
org.mybatis.spring.boot
mybatis-spring-boot-starter
1.3.1
- application.yml
server:
port: 9090
spring:
thymeleaf:
prefix: classpath:/templates/
suffix: .html
mode: HTML5
encoding: UTF-8
datasource:
url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8
username: root
password: root
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
mapper-locations: classpath:/mapping/*.xml
type-aliases-package: com.southwind.entity
- UserRepository
package com.southwind.mapper;
import com.southwind.entity.User;
import java.util.List;
public interface UserRepository {
public List findAll(int index,int limit);
public User findById(long id);
public void save(User user);
public void update(User user);
public void deleteById(long id);
public int count();
}
- UserRepository.xml
insert into user(name,score) values(#{name},#{score})
update user set name = #{name},score = #{score} where id = #{id}
delete from user where id = #{id}
- User
package com.southwind.entity;
import lombok.Data;
import org.hibernate.validator.constraints.Length;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
@Data
public class User {
@NotNull(message = "id不能为空")
private Long id;
@NotEmpty(message = "姓名不能为空")
@Length(min = 2,message = "姓名长度不能小于2位")
private String name;
@Min(value = 60,message = "成绩必须大于60分")
private double score;
}
- Handler
package com.southwind.controller;
import com.southwind.entity.User;
import com.southwind.mapper.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
@Controller
@RequestMapping("/mapper")
public class UserMapperHandler {
@Autowired
private UserRepository userRepository;
private int limit = 10;
@GetMapping("/findAll/{page}")
public ModelAndView findAll(@PathVariable("page") int page){
ModelAndView modelAndView = new ModelAndView();
int index = (page-1)*limit;
modelAndView.setViewName("show");
modelAndView.addObject("list",userRepository.findAll(index,limit));
modelAndView.addObject("page",page);
//计算总页数
int count = userRepository.count();
int pages = 0;
if(count%limit == 0){
pages = count/limit;
}else{
pages = count/limit+1;
}
modelAndView.addObject("pages",pages);
return modelAndView;
}
@GetMapping("/deleteById/{id}")
public String deleteById(@PathVariable("id") long id){
userRepository.deleteById(id);
return "redirect:/mapper/findAll/1";
}
@GetMapping("/findById")
public ModelAndView findById(@RequestParam("id") long id){
ModelAndView modelAndView = new ModelAndView();
modelAndView.addObject("user",userRepository.findById(id));
modelAndView.setViewName("update");
return modelAndView;
}
@PostMapping("/update")
public String update(User user){
userRepository.update(user);
return "redirect:/mapper/findAll/1";
}
@PostMapping("/save")
public String save(User user){
userRepository.save(user);
return "redirect:/mapper/findAll/1";
}
@GetMapping("/redirect/{name}")
public String redirect(@PathVariable("name") String name){
return name;
}
}
- HTML
Title
Title
Title
用户信息
用户ID
用户名
成绩
操作
删除
修改
首页
上一页
/
下一页
尾页
添加用户