接着上一节的
第一步：在pom文件中加入以下代码：
<!--JPA-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency> <!-- MySql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
第二步：在application.yml文件中加入以下代码
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
#useUnicode=true&characterEncoding=utf-8:这个代表允许用户自己设定数据库编码，而且设置成UTF-8
#&useSSL=false:
url: jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf-8&useSSL=false
username: root
password: root jpa:
hibernate:
ddl-auto: update
#ddl-auto:有五个值可选，create：是每次都是先检查表是否存在，如果存在删除再新建；update：不会新建只是更新；
# create-drop：新建但是一旦sessionFactory停止就自动销毁；none：什么都不做；validate：验证表结构 show-sql: true
#show-sql：是否显示sql语句
第三步：在bean包选新建User类
package com.oda.springboot.bean; import org.springframework.stereotype.Component; import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id; //@Component
@Entity
//@Entity说明这个class是实体类，并且使用默认的orm规则，即class名即数据库表中表名，class字段名即表中的字段名
//如果想改变这种默认的orm规则，就要使用@Table来改变class名与数据库中表名的映射规则，@Column来改变class中字段名与db中表的字段名的映射规则
public class User {
@Id
@GeneratedValue
private int id;
private String name;
private int age; public User() {
} public User(int id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
} public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
}
}
第四步：新建dao包，在其下面新建UserMapper接口
package com.oda.springboot.dao; import com.oda.springboot.bean.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository; public interface UserMapper extends JpaRepository<User,Integer> {
}
第五步：新建service包，在其下面新建Userservice类
package com.oda.springboot.service; import com.oda.springboot.bean.User;
import com.oda.springboot.dao.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service; import javax.annotation.Resource;
import java.util.List; @Service
public class UserService {
@Autowired
private UserMapper userMapper; public List<User> users() {
return userMapper.findAll();
}
}
第六步：在controller包下新建UserController
package com.oda.springboot.controller; import com.oda.springboot.bean.User;
import com.oda.springboot.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping; import javax.annotation.Resource;
import java.util.List; @Controller
public class UserController { @Resource
private UserService userService; @RequestMapping("/users")
public String uses(){
return "redirect:/select";
} @RequestMapping("/select")
public String select(Model model){
List<User> users = userService.users();
model.addAttribute("users",users);
return "users/index";
}
}
第七步：在templates包下，新建users包，在其下新建index.html
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org"><!--这里引入thymeleaf命名空间-->
<head>
<meta charset="UTF-8">
<title>thymeleaf模板的应用</title>
</head>
<body>
<table>
<tr>
<td>序号</td>
<td>名字</td>
<td>年龄</td>
</tr>
<tr th:each="user,count:${users}">
<td th:text="${count.count}"></td>
<td th:text="${user.name}"></td>
<td th:text="${user.age}"></td>
</tr>
</table> </body>
</html>
然后启动，访问http://localhost:8080/zm/users
项目结构：
注意：application.yml文件中的
url: jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf-8&useSSL=false