1,POM

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>

   <groupId>
 
com.hipad</groupId>
   <artifactId>data-jpa</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>data-jpa</name>
   <description>spring-data-jpa</description>

   <parent>
      <groupId>org.springframework.boot</
 
groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.0.2.RELEASE</version>
      <relativePath/> <!-- lookup parent from repository -->
</parent>

   <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding
 
>
      <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
      <java.version>1.8</java.version>
   </properties>

   <dependencies>
      <!-- Web 依賴 -->
<dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
      <!-- 測試依賴 -->
<dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-data-jpa</artifactId>
         <version>RELEASE</version>
      </dependency>
      <!-- 模板引擎 Thymeleaf 依賴 -->
<dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-thymeleaf</artifactId>
      </dependency>

      <dependency>
         <groupId>com.h2database</groupId>
         <artifactId>h2</artifactId>
         <scope>runtime</scope>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
      </plugins>
   </build>


</project>

2，resources

spring.jpa.show-sql=true

3,springboot入口

package com.hipad;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class DataJpaApplication {

   public static void main(String[] args) {
      SpringApplication.run(DataJpaApplication.class, args);
   }
}

4，Contorller

package com.hipad.controller;

import com.hipad.domain.Book;
import com.hipad.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

/**
 * @author: create by libin
 * @version: v1.0
 * @description: com.hipad.controller
 * @date:2018/5/12
*/
@Controller
@RequestMapping(value = "book")
public class UserController {
    @Autowired
UserService userService;
    @RequestMapping(method = RequestMethod.GET)
    public String findPage(ModelMap map){
        map.addAttribute("bookList",userService.findAll());
        return "bookList";
    }
    @RequestMapping(value = "create",method = RequestMethod.GET)
    public String createPage(ModelMap map){
        Book book = new Book();
        book.setName("java從入門到放棄");
        book.setWriter("名字");
        book.setIntroduction("這是講述學習java的心酸歷程");
        map.addAttribute("book",book);
        map.addAttribute("action","create");
        return "bookForm";
    }
    @RequestMapping(value = "create",method = RequestMethod.POST)
    public String addPage(@ModelAttribute Book book){
      Book save=  userService.addAll(book);
      if(save!=null){
          return "redirect:/book";// 這裡注意寫redirect:/book，不然拿不到值
}
        return "bookForm";
    }
    @RequestMapping(value = "delete/{id}",method = RequestMethod.GET)
    public String delete(@PathVariable Long id){
        userService.delete(id);
        return "redirect:/book";
    }
    @RequestMapping(value = "update/{id}",method = RequestMethod.GET)
    public String update(ModelMap map,@PathVariable Long id){
        Book book = userService.findById(id);
        map.addAttribute("book",book);
        map.addAttribute("action","update");
        return "bookForm";
    }
    @RequestMapping(value = "update",method = RequestMethod.POST)
    public String updateById(@ModelAttribute Book book){
        userService.updateById(book);
        return "redirect:/book";
    }
}

5，service

package com.hipad.service;

import com.hipad.domain.Book;

import java.util.List;

/**
 * @author: create by libin
 * @version: v1.0
 * @description: com.hipad.service
 * @date:2018/5/12
*/
public interface UserService {
    List<Book> findAll();

    Book  addAll(Book book);

    void delete(Long id);

    Book findById(Long id);

    void updateById(Book book);
}

package com.hipad.service.impl;

import com.hipad.domain.Book;
import com.hipad.domain.UserRepository;
import com.hipad.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author: create by libin
 * @version: v1.0
 * @description: com.hipad.service.impl
 * @date:2018/5/12
*/
@Service
public class UserServiceImpl implements UserService {
    @Autowired
UserRepository userRepository;
    @Override
public List<Book> findAll() {
        return userRepository.findAll();
    }

    @Override
public Book addAll(Book book) {
        Book save = userRepository.save(book);
        return save;
    }

    @Override
public void delete(Long id) {
        userRepository.deleteById(id);
    }

    @Override
public Book findById(Long id) {
        return userRepository.findById(id).get();
    }

    @Override
public void updateById(Book book) {
        userRepository.save(book);
    }


}

6，domain

package com.hipad.domain;

import org.springframework.data.jpa.repository.JpaRepository;

/**
 * @author: create by libin
 * @version: v1.0
 * @description: com.hipad.domain
 * @date:2018/5/12
*/
public interface UserRepository extends JpaRepository<Book,Long>{

}

package com.hipad.domain;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import java.io.Serializable;

/**
 * @author: create by libin
 * @version: v1.0
 * @description: com.hipad.domain
 * @date:2018/5/12
*/
@Entity
public class Book  implements Serializable {
    @Id
    @GeneratedValue
private Long id;
    private String name;
    private String writer;
    private String introduction;
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getWriter() {
        return writer;
    }

    public void setWriter(String writer) {
        this.writer = writer;
    }

    public String getIntroduction() {
        return introduction;
    }

    public void setIntroduction(String introduction) {
        this.introduction = introduction;
    }
    @Override
public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", writer='" + writer + '\'' +
                ", introduction='" + introduction + '\'' +
                '}';
    }
}

th:action="@{/book/{action}(action=${action})}"