Spring boot2+jpa+thymeleaf实现增删改查

时间:2021-05-20

一、pom.xml引入相关模块web、jpa、thymeleaf、oracle:

<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>com.oracle</groupId> <artifactId>ojdbc8</artifactId> <version>12.2.0.1</version> </dependency>

二、application.properties配置

server.port = 9001spring.datasource.driver-class-name = oracle.jdbc.driver.OracleDriverspring.datasource.url = jdbc:oracle:thin:@127.0.0.1:1521:testdbspring.datasource.username = devspring.datasource.password = devspring.jpa.hibernate.ddl-auto = updatespring.jpa.show-sql = truespring.thymeleaf.cache = false

说明:

1、由于本机的8080已经被使用,修改一下端口号为9001。

2、hibernate.hbm2ddl.auto参数有四个值:

create: 每次加载hibernate时都会删除上一次的生成的表,然后根据你的model类再重新来生成新表,哪怕两次没有任何改变也要
这样执行,这就是导致数据库表数据丢失的一个重要原因。

create-drop :每次加载hibernate时根据model类生成表,但是sessionFactory一关闭,表就自动删除。

update:最常用的属性,第一次加载hibernate时根据model类会自动建立起表的结构(前提是先建立好数据库),以后加载
hibernate时根据 model类自动更新表结构,即使表结构改变了但表中的行仍然存在不会删除以前的行。要注意的是当部署到服务器后,表结构是不会被马上建立起来的,是要等 应用第一次运行起来后才会。
validate :每次加载hibernate时,验证创建数据库表结构,只会和数据库中的表进行比较,不会创建新表,但是会插入新值。

3、show-sql 是否打印出自动生产的SQL,方便调试的时候查看

4、propertiesspring.thymeleaf.cache=false是关闭thymeleaf的缓存,不然在开发过程中修改页面不会立刻生效需要重启,生产
可配置为true。

三、启动类需要添加Servlet的支持

package com.example.demo;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.builder.SpringApplicationBuilder;import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;@SpringBootApplicationpublic class DemoApplication extends SpringBootServletInitializer { @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { return application.sources(DemoApplication.class); } public static void main(String[] args) { SpringApplication.run(DemoApplication.class, args); }}

四、数据库层代码

1、实体类映射数据库表

package com.example.demo.entity;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.Table;import javax.validation.constraints.NotEmpty;import org.hibernate.validator.constraints.Length;@Entity@Table(name = "userinfo")public class User { @Id @GeneratedValue private long id; @Column(nullable = false, unique = true) @NotEmpty(message="用户名不能为空") private String userName; @Column(nullable = false) @NotEmpty(message="密码不能为空") @Length(min=6, message="密码长度不能少于6位") private String password; @Column(nullable = false) private int age; //必须有构造 public User() { } public long getId() { return id; } public User setId(long id) { this.id = id; return this; } public String getUserName() { return userName; } public User setUserName(String userName) { this.userName = userName; return this; } public String getPassword() { return password; } public User setPassword(String password) { this.password = password; return this; } public int getAge() { return age; } public User setAge(int age) { this.age = age; return this; }}

2、继承JpaRepository类会自动实现很多内置的方法

package com.example.demo.repository;import org.springframework.data.jpa.repository.JpaRepository;import com.example.demo.entity.User;public interface UserRepository extends JpaRepository<User, Long> { User findById(long id); void deleteById(Long id);}

五、业务层

service调用jpa实现相关的增删改查,实际项目中service层处理具体的业务代码。

1、UserService.java

package com.example.demo.service;import java.util.List;import org.springframework.data.domain.Page;import org.springframework.data.domain.Pageable;import com.example.demo.entity.User;public interface UserService { public Page<User> getUserPage(Pageable pageable); public List<User> getUserList(); public User findUserById(long id); public void save(User user); public void edit(User user); public void delete(long id);}

2、UserServiceImpl.java

package com.example.demo.service.impl;import java.util.List;import java.util.Optional;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.data.domain.Page;import org.springframework.data.domain.Pageable;import org.springframework.stereotype.Service;import com.example.demo.entity.User;import com.example.demo.repository.UserRepository;import com.example.demo.service.UserService;@Servicepublic class UserServiceImpl implements UserService { @Autowired private UserRepository userRepository; @Override public Page<User> getUserPage(Pageable pageable) { return userRepository.findAll(pageable); } @Override public List<User> getUserList() { return userRepository.findAll(); } @Override public User findUserById(long id) { return userRepository.findById(id) ; } @Override public void save(User user) { userRepository.save(user); } @Override public void edit(User user) { userRepository.save(user); } @Override public void delete(long id) { userRepository.deleteById(id); }}

六、控制层

package com.example.demo.web.controller;import java.util.List;import javax.annotation.Resource;import javax.validation.Valid;import org.springframework.data.domain.Page;import org.springframework.data.domain.PageRequest;import org.springframework.data.domain.Pageable;import org.springframework.data.domain.Sort;import org.springframework.data.domain.Sort.Direction;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.validation.BindingResult;import org.springframework.validation.ObjectError;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import com.example.demo.entity.User;import com.example.demo.service.UserService;@Controllerpublic class UserController { @Resource UserService userService; @RequestMapping("/") public String index() { return "redirect:/list"; } @RequestMapping("/list") public String list(Model model) { List<User> users=userService.getUserList(); model.addAttribute("users", users); return "user/list"; } @RequestMapping("/toAdd") public String toAdd() { return "user/userAdd"; } @RequestMapping("/add") public @ResponseBody User add(@Valid User user, BindingResult result) { if (result.hasErrors()) { List<ObjectError> list = result.getAllErrors(); for (ObjectError error : list) { System.out.println(error.getDefaultMessage()); } return null; } userService.save(user); return user; } @RequestMapping("/toEdit") public String toEdit(Model model,Long id) { User user=userService.findUserById(id); model.addAttribute("user", user); return "user/userEdit"; } @RequestMapping("/edit") public String edit(User user) { userService.edit(user); return "redirect:/list"; } @RequestMapping("/delete") public String delete(Long id) { userService.delete(id); return "redirect:/list"; }}

七、页面

1、列表页 list.hmtl

<!DOCTYPE html><html lang="en" xmlns:th="http://www.thymeleaf.org"><head> <meta charset="UTF-8"/> <title>userList</title> <link rel="stylesheet" th:href="@{/css/bootstrap.css}" rel="external nofollow" rel="external nofollow" rel="external nofollow" ></link></head><body class="container"><br/><h1>用户列表</h1><br/><br/><div class="with:80%"> <table class="table table-hover"> <thead> <tr> <th>#</th> <th>User Name</th> <th>Password</th> <th>Age</th> <th>Edit</th> <th>Delete</th> </tr> </thead> <tbody> <tr th:each="user : ${users}"> <th scope="row" th:text="${user.id}">1</th> <td th:text="${user.userName}">neo</td> <td th:text="${user.password}">Otto</td> <td th:text="${user.age}">6</td> <td><a th:href="@{/toEdit(id=${user.id})}" rel="external nofollow" >edit</a></td> <td><a th:href="@{/delete(id=${user.id})}" rel="external nofollow" >delete</a></td> </tr> </tbody> </table></div><div class="form-group"> <div class="col-sm-2 control-label"> <a href="/toAdd" rel="external nofollow" rel="external nofollow" th:href="@{/toAdd}" rel="external nofollow" class="btn btn-info">add</a> </div></div></body></html>

2、新增页 userAdd.html

<!DOCTYPE html><html lang="en" xmlns:th="http://www.thymeleaf.org"><head> <meta charset="UTF-8"/> <title>user</title> <link rel="stylesheet" th:href="@{/css/bootstrap.css}" rel="external nofollow" rel="external nofollow" rel="external nofollow" ></link></head><body class="container"><br/><h1>添加用户</h1><br/><br/><div class="with:80%"> <form class="form-horizontal" th:action="@{/add}" method="post"> <div class="form-group"> <label for="userName" class="col-sm-2 control-label">userName</label> <div class="col-sm-10"> <input type="text" class="form-control" name="userName" id="userName" placeholder="userName"/> </div> </div> <div class="form-group"> <label for="password" class="col-sm-2 control-label" >Password</label> <div class="col-sm-10"> <input type="password" class="form-control" name="password" id="password" placeholder="Password"/> </div> </div> <div class="form-group"> <label for="age" class="col-sm-2 control-label">age</label> <div class="col-sm-10"> <input type="text" class="form-control" name="age" id="age" placeholder="age"/> </div> </div> <div class="form-group"> <div class="col-sm-offset-2 col-sm-10"> <input type="submit" value="Submit" class="btn btn-info" /> &nbsp; &nbsp; &nbsp; <input type="reset" value="Reset" class="btn btn-info" /> </div> </div> </form></div></body></html>

3、修改页 userEdit.html

<!DOCTYPE html><html lang="en" xmlns:th="http://www.thymeleaf.org"><head> <meta charset="UTF-8"/> <title>user</title> <link rel="stylesheet" th:href="@{/css/bootstrap.css}" rel="external nofollow" rel="external nofollow" rel="external nofollow" ></link></head><body class="container"><br/><h1>修改用户</h1><br/><br/><div class="with:80%"> <form class="form-horizontal" th:action="@{/edit}" th:object="${user}" method="post"> <input type="hidden" name="id" th:value="*{id}" /> <div class="form-group"> <label for="userName" class="col-sm-2 control-label">userName</label> <div class="col-sm-10"> <input type="text" class="form-control" name="userName" id="userName" th:value="*{userName}" placeholder="userName"/> </div> </div> <div class="form-group"> <label for="password" class="col-sm-2 control-label" >Password</label> <div class="col-sm-10"> <input type="password" class="form-control" name="password" id="password" th:value="*{password}" placeholder="Password"/> </div> </div> <div class="form-group"> <label for="age" class="col-sm-2 control-label">age</label> <div class="col-sm-10"> <input type="text" class="form-control" name="age" id="age" th:value="*{age}" placeholder="age"/> </div> </div> <div class="form-group"> <div class="col-sm-offset-2 col-sm-10"> <input type="submit" value="Submit" class="btn btn-info" /> &nbsp; &nbsp; &nbsp; <a href="/toAdd" rel="external nofollow" rel="external nofollow" th:href="@{/list}" rel="external nofollow" class="btn btn-info">Back</a> </div> </div> </form></div></body></html>

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。

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