• SpringBoot笔记


    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 SpringCloud 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。
    <!-- 继承⽗包 -->
    <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.7.RELEASE</version>
    </parent>
    <dependencies>
    <!-- web启动jar -->
    <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.6</version>
    <scope>provided</scope>
    </dependency>
    </dependencies>
    2、创建 Student 实体类
    package com.val.entity;
    import lombok.Data;
    @Data
    public class Student {
    private long id;
    private String name;
    private int age;
    }
    3、StudentRepository
    package com.val.repository;
    import com.val.entity.Student;
    import java.util.Collection;
    public interface StudentRepository {
    public Collection<Student> findAll();
    public Student findById(long id);
    public void saveOrUpdate(Student student);
    public void deleteById(long id);
    }
    4、StudentRepositoryImpl
    package com.val.repository.impl;
    import com.val.entity.Student;
    import com.val.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<Long,Student> 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<Student> 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.val.controller;
    import com.val.entity.Student;
    import com.val.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<Student> findAll(){
    return studentRepository.findAll();
    }
    @GetMapping("/findById/{id}")
    public Student findById(@PathVariable("id") long id){
    return studentRepository.findById(id);
    6、application.yml
    server:
    port: 9090
    7、启动类
    package com.val;
    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
    <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.7.RELEASE</version></parent>
    <dependencies>
    <!-- web -->
    <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!-- 整合JSP -->
    <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    </dependency>
    <dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
    </dependency>
    <!-- JSTL -->
    <dependency>
    <groupId>jstl</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
    </dependency>
    <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.6</version>
    <scope>provided</scope>
    </dependency>
    </dependencies>
     
    • 创建配置⽂件 application.yml  
     
     
    • 创建 Handler
    package com.val.controller;import com.southwind.entity.Student;
    import com.val.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.
    Date: 2020-06-12
    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" %>
    <html>
    <head>
      <title>Title</title>
    </head>
    <body>
      <h1>学⽣信息</h1>
      <table>
        <tr>
    <th>学⽣编号</th>
    <th>学⽣姓名</th>
    <th>学⽣年龄</th>
    <th>操作</th>
        </tr>
        <c:forEach items="${list}" var="student">
          <tr>
    <td>${student.id}</td>
    <td>${student.name}</td>
    <td>${student.age}</td>
              <td>
    <a href="/hello/findById/${student.id}">修改</a>
    <a href="/hello/deleteById/${student.id}">删除</a>
             </td>
           </tr>
          </c:forEach>
        </table>
        <a href="/save.jsp">添加学⽣</a>
    </body>
    </html>
    <%--
    Created by IntelliJ IDEA.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。
    User: val
    Date: 2020-06-12
    Time: 12:09
    To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
    <title>Title</title>
    </head>
    <body>
    <form action="/hello/save" method="post">
    ID:<input type="text" name="id"/><br/>
    name:<input type="text" name="name"/><br/>
    age:<input type="text" name="age"/><br/>
    <input type="submit" value="提交"/>
    </form>
    </body>
    </html>
     
    <%--
    Created by IntelliJ IDEA.
    User: val
    Date: 2020-06-12
    Time: 12:09
    To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
    <title>Title</title>
    </head>
    <body>
    <form action="/hello/update" method="post">
    ID:<input type="text" name="id" value="${student.id}" readonly/><br/>
    name:<input type="text" name="name" value="${student.name}"/><br/>
    age:<input type="text" name="age" value="${student.age}"/><br/>
    <input type="submit" value="提交"/>
    </form>
    </body>
    </html>
     
    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。
    <p th:text="${message}"></p>
    • pom.xml
    <!-- 继承⽗包 -->
    <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.7.RELEASE</version>
    </parent>
    <dependencies>
    <!-- web启动jar -->
    <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.6</version>
    <scope>provided</scope>
    </dependency>
    <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
    </dependencies>
    • appliction.yml
    server:
    port: 9090
    spring:
    thymeleaf:
    prefix: classpath:/templates/
    suffix: .html
    mode: HTML5
    encoding: UTF-8
    • Handler
    package com.val.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
    <!DOCTYPE html>
    <html lang="en">
    <head>
    <meta charset="UTF-8">
    <title>Title</title>
    </head>
    <body>
    <h1>Hello World</h1>
    </body>
    </html>
    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<String,String> map){
    map.put("name","张三");
    return "index";
    }
    <p th:text="${name}"></p>
    <p th:text="'学⽣姓名是'+${name}+2"></p>
    <p th:text="|学⽣姓名是,${name}|"></p>
    • 条件判断:if/unless
    th:if 表示条件成⽴时显示内容,th:unless 表示条件不成⽴时显示内容
    @GetMapping("/if")
    public String index3(Map<String,Boolean> map){
    map.put("flag",true);
    return "index";
    }
    <p th:if="${flag == true}" th:text="if判断成⽴"></p>
    <p th:unless="${flag != true}" th:text="unless判断成⽴"></p>
    • 循环
    @GetMapping("/index")
    public String index(Model model){
    System.out.println("index...");
    List<Student> list = new ArrayList<>();
    list.add(new Student(1L,"张三",22));
    list.add(new Student(2L,"李四",23));
    list.add(new Student(3L,"王五",24));
    model.addAttribute("list",list);
    return "index";
    }
    <table>
    <tr>
    <th>index</th>
    <th>count</th>
    <th>学⽣ID</th>
    <th>学⽣姓名</th>
    <th>学⽣年龄</th>
    </tr>
    <tr th:each="student,stat:${list}" th:style="'background
    color:'+@{${stat.odd}?'#F2F2F2'}">
    <td th:text="${stat.index}"></td>
    <td th:text="${stat.count}"></td>
    <td th:text="${student.id}"></td>
    <td th:text="${student.name}"></td>
    <td th:text="${student.age}"></td>
    </tr>
    </table>
    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)
    • fifirst 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
    <h1>Hello World</h1>
    <a th:href="@{http://www.baidu.com}">跳转</a>
    <a th:href="@{http://localhost:9090/index/url/{na}(na=${name})}">跳转2</a>
    <img th:src="${src}">
    <div th:style="'background:url('+ @{${src}} +');'">
    <br/>
    <br/>
    <br/>
    </div>
    • 三元运算
    @GetMapping("/eq")
    public String eq(Model model){
    model.addAttribute("age",30);
    return "test";
    }
    <input th:value="${age gt 30?'中年':'⻘年'}"/>
    • 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";}
     
    <div th:switch="${gender}">
    <p th:case="⼥">⼥</p>
    <p th:case="男">男</p>
    <p th:case="*">未知</p>
    </div>
    • 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";
    }
     
    <p th:text="${#request.getAttribute('request')}"></p>
    <p th:text="${#session.getAttribute('session')}"></p>
    <p th:text="${#locale.country}"></p>
    • 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
    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";
    }
     
    <!-- 格式化时间 -->
    <p th:text="${#dates.format(date,'yyyy-MM-dd HH:mm:sss')}"></p>
    <!-- 创建当前时间,精确到天 -->
    <p th:text="${#dates.createToday()}"></p>
    <!-- 创建当前时间,精确到秒 -->
    <p th:text="${#dates.createNow()}"></p>
    <!-- 判断是否为空 -->
    <p th:text="${#strings.isEmpty(name)}"></p>
    <!-- 判断List是否为空 -->
    <p th:text="${#lists.isEmpty(users)}"></p>
    <!-- 输出字符串⻓度 -->
    <p th:text="${#strings.length(name)}"></p>
    <!-- 拼接字符串 -->
    <p th:text="${#strings.concat(name,name,name)}"></p>
    <!-- 创建⾃定义字符串 -->
    <p th:text="${#strings.randomAlphanumeric(count)}"></p>
    Spring Boot 数据校验
    package com.vl.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 = "姓名⻓度不能⼩于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<ObjectError> list = bindingResult.getAllErrors();
    for(ObjectError objectError:list){
    System.out.println(objectError.getCode()+"-
    "+objectError.getDefaultMessage());
    }
    }
    }
    Spring Boot 整合 JDBC
    • pom.xml
    <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.11</version>
    </dependency>
    • 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.vl.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 = "姓名⻓度不能⼩于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<User> 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<User> 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<User> 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
    <dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.1</version>
    </dependency>
     
    • 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.val.entity
    • UserRepository
    package com.southwind.mapper;
    import com.southwind.entity.User;import java.util.List;
    public interface UserRepository {
    public List<User> 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
    <?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.southwind.mapper.UserRepository">
    <select id="findAll" resultType="User">
    select * from user limit #{param1},#{param2}
    </select>
    <select id="count" resultType="int">
    select count(id) from user
    </select>
    <select id="findById" parameterType="long" resultType="User">
    select * from user where id = #{id}
    </select>
    <insert id="save" parameterType="User">
    insert into user(name,score) values(#{name},#{score})
    </insert>
    <update id="update" parameterType="User">
    update user set name = #{name},score = #{score} where id = #{id}
    </update>
    <delete id="deleteById" parameterType="long">
    delete from user where id = #{id}
    </delete>
    </mapper>
    • 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 = "姓名⻓度不能⼩于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);
    //计算总⻚数
    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
    <!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <html lang="en">
    <head>
    <meta charset="UTF-8">
    <title>Title</title>
    </head>
    <body>
    <form action="/mapper/save" method="post">
    ⽤户姓名:<input type="text" name="name" /><br/> ⽤户成绩:<input type="text" name="score" /><br/>
    <input type="submit" value="提交"/>
    </form>
    </body>
    </html>
    <!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <html lang="en">
    <head>
    <meta charset="UTF-8">
    <title>Title</title>
    </head>
    <body>
    <form action="/mapper/update" method="post">
    ⽤户ID:<input type="text" name="id" th:value="${user.id}" readonly/>
    <br/>
    ⽤户姓名:<input type="text" name="name" th:value="${user.name}" /><br/>
    ⽤户成绩:<input type="text" name="score" th:value="${user.score}" /><br/>
    <input type="submit" value="提交"/>
    </form>
    </body>
    </html>
     
    <!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <html lang="en">
    <head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript" th:src="@{/jquery-3.3.1.min.js}"></script>
    <script type="text/javascript">
    $(function(){
    $("#first").click(function(){
    var page = $("#page").text();
    page = parseInt(page);
    if(page == 1){
    return false;
    }
    window.location.href="/mapper/findAll/1";
    });
    $("#previous").click(function(){
    var page = $("#page").text();
    page = parseInt(page); if(page == 1){
    return false;
    }
    page = page-1;
    window.location.href="/mapper/findAll/"+page;
    });
    $("#next").click(function(){
    var page = $("#page").text();
    var pages = $("#pages").text();
    if(page == pages){
    return false;
    }
    page = parseInt(page);
    page = page+1;
    window.location.href="/mapper/findAll/"+page;
    });
    $("#last").click(function(){
    var page = $("#page").text();
    var pages = $("#pages").text();
    if(page == pages){
    return false;
    }
    window.location.href="/mapper/findAll/"+pages;
    });
    });
    </script>
    </head>
    <body>
    <h1>⽤户信息</h1>
    <table>
    <tr>
    <th>⽤户ID</th>
    <th>⽤户名</th>
    <th>成绩</th>
    <th>操作</th>
    </tr>
    <tr th:each="user:${list}">
    <td th:text="${user.id}"></td>
    <td th:text="${user.name}"></td>
    <td th:text="${user.score}"></td>
    <td>
    <a th:href="@{/mapper/deleteById/{id}(id=${user.id})}">删除</a>
    <a th:href="@{/mapper/findById(id=${user.id})}">修改</a>
    </td>
    </tr>
    </table>
    <a id="first" href="javascript:void(0)">⾸⻚</a>
    <a id="previous" href="javascript:void(0)">上⼀⻚</a>
    <span id="page" th:text="${page}"></span>/<span id="pages"th:text="${pages}"></span>
    <a id="next" href="javascript:void(0)">下⼀⻚</a>
    <a id="last" href="javascript:void(0)">尾⻚</a><br/>
    <a href="/mapper/redirect/save">添加⽤户</a>
    </body>
    </html>
     
     
     
     
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  • 原文地址:https://www.cnblogs.com/val-record/p/13098292.html
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