spring boot2+jpa+thymeleaf增删改查例子

参考这遍文章做了一个例子，稍微不同之处，原文是spring boot、mysql，这里改成了spring boot 2、Oracle。

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 = 9001

spring.datasource.driver-class-name = oracle.jdbc.driver.OracleDriver
spring.datasource.url = jdbc:oracle:thin:@127.0.0.1:1521:testdb
spring.datasource.username = dev
spring.datasource.password = dev

spring.jpa.hibernate.ddl-auto = update
spring.jpa.show-sql = true

spring.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;

@SpringBootApplication
public 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;

@Service
public 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;

@Controller
public 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);

        /*int page=1,size=2;
        Sort sort = new Sort(Direction.DESC, "id");
        Pageable pageable = PageRequest.of(page, size, sort);
        model.addAttribute("users", pageable);*/

        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}"></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})}">edit</a></td>
            <td><a th:href="@{/delete(id=${user.id})}">delete</a></td>
        </tr>
        </tbody>
    </table>
</div>
<div class="form-group">
    <div class="col-sm-2 control-label">
        <a href="/toAdd" th:href="@{/toAdd}" 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}"></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}"></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" th:href="@{/list}" class="btn btn-info">Back</a>
            </div>

        </div>
    </form>
</div>
</body>
</html>