Question

我正在尝试学习如何使用springboot和thymeleaf创建一个Web应用程序。作为练习，我想在一个简单的html表中用mysql（人物）创建的随机数据库表中显示两列。

我已经使用了几个教程并编写了下面的代码但是我的html不显示数据库的内容只有表头。我完全不知道我错在哪里。我在这里查了其他问题，他们都在使用一种名为jpa的东西。这比我的做法好吗？如果是这样，我在哪里可以找到初学者的教程。

代码

应用类

package ro.database.jdbcTest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableAsync;
import ro.database.jdbcTest.controllers.UsersController;

@SpringBootApplication
@EnableAsync
public class App
{
    @Autowired
    UsersController service;

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

}

控制器

package ro.database.jdbcTest.controllers;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import ro.database.jdbcTest.model.Users;
import ro.database.jdbcTest.services.UserService;

import java.util.List;
import java.util.Map;


@Controller
public class UsersController {

    @Autowired
    UserService service;

    @RequestMapping(value = "/user", method = RequestMethod.GET)
    public String index(Model md){
        md.addAttribute("user", service.findAll());

        return "user";
    }
}

服务类

package ro.database.jdbcTest.services;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Service;
import ro.database.jdbcTest.model.Users;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@Service
public class UserService {

    @Autowired
    JdbcTemplate template;

    public List<Users> findAll() {
        String sql = "select * from people";
        RowMapper<Users> rm = new RowMapper<Users>() {
            @Override
            public Users mapRow(ResultSet resultSet, int i) throws SQLException {
                Users user = new Users(resultSet.getInt("id"),
                        resultSet.getString("name"),
                        resultSet.getInt("age"));
                String email = resultSet.getString("email");
                if (email != null) {
                    user.setEmail(email);
                }

                return user;
            }
        };

        return template.query(sql, rm);
    }

模型类

package ro.database.jdbcTest.model;

public class Users {

        private int id;
        private String name;
        private int age;
        private String email;

        public Users(int id, String name, int age){
            this.id=id;
            this.name=name;
            this.age=age;
        }

        public void setEmail(String email){
            this.email=email;
        }
}

HTML

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h2>Users</h2>
<table border="1">
    <tr>
        <th>name</th>
        <th>age</th>
    </tr>
    <tr th:each = "user: ${users}">
        <td th:text="${user.name}">vasile</td>
        <td th:text="${user.age}">45</td>
    </tr>
</table>
</body>
</html>

Answer 1

您已在user中的变量modelAttribute中绑定用户。尝试在您使用users作为列表

的HTML中绑定为users原因

md.addAttribute("users", service.findAll());
return "user";

Springboot + thymeleaf在html表中显示数据库内容

1 个答案: