Springboot+thymeleaf简单整合

Springboot+thymeleaf整合

简单功能实现（增删改查）

功能分析方法参考

https://www.cnblogs.com/djhzzl/p/14087746.html

源码：https://github.com/345404748/Demo-Employee

访问，代码运行实现效果：

http://localhost:8080/admin

 点击查询

 换部门查询

 

 

 

 

 添加操作

 

 删除操作

点击即进行删除

 

 

 

 编辑操作

 

 

 代码部分：

 

 

开发工具：IDEA 2019.2

数据库：Mysql 5.7

在Mysql中创建表

  • employee表

CREATE TABLE `employee` (
  `employee_id` int(11) NOT NULL AUTO_INCREMENT,
  `employee_name` varchar(255) DEFAULT NULL,
  `employee_age` int(11) DEFAULT NULL,
  `department_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`employee_id`)
) ENGINE=InnoDB AUTO_INCREMENT=38 DEFAULT CHARSET=utf8;
employee表

  • department表

CREATE TABLE `department` (
  `department_id` int(11) NOT NULL AUTO_INCREMENT,
  `department_name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`department_id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
department表

demo项目：

  • 配置yml文件

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/employee?serverTimezone=UTC
    username: root
    password: admin

mybatis:
  mapper-locations: mapper/*.xml
  type-aliases-package: com.djh.demo.bean
application.yml

  • 配置pom文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.djh</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

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

</project>
pom.xm

实体类（pojo）：

生成get\set方法、重写toString方法

  • Employee.class

package com.djh.demo.bean;

/**
 * @author HP
 * @data 2020-12-04
 */

public class Employee {
    private Integer employee_id;
    private String employee_name;
    private Integer employee_age;

    private Department department;

    public Integer getEmployee_id() {
        return employee_id;
    }

    public void setEmployee_id(Integer employee_id) {
        this.employee_id = employee_id;
    }

    public String getEmployee_name() {
        return employee_name;
    }

    public void setEmployee_name(String employee_name) {
        this.employee_name = employee_name;
    }

    public Integer getEmployee_age() {
        return employee_age;
    }

    public void setEmployee_age(Integer employee_age) {
        this.employee_age = employee_age;
    }

    public Department getDepartment() {
        return department;
    }

    public void setDepartment(Department department) {
        this.department = department;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "employee_id=" + employee_id +
                ", employee_name='" + employee_name + '\'' +
                ", employee_age=" + employee_age +
                '}';
    }
}
Employee

  • Department.class

package com.djh.demo.bean;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */
public class Department {
    private Integer department_id;
    private String department_name;
    private List<Employee> employees;

    public Integer getDepartment_id() {
        return department_id;
    }

    public void setDepartment_id(Integer department_id) {
        this.department_id = department_id;
    }

    public String getDepartment_name() {
        return department_name;
    }

    public void setDepartment_name(String department_name) {
        this.department_name = department_name;
    }

    public List<Employee> getEmployees() {
        return employees;
    }

    public void setEmployees(List<Employee> employees) {
        this.employees = employees;
    }

    @Override
    public String toString() {
        return "Department{" +
                "department_id=" + department_id +
                ", department_name='" + department_name + '\'' +
                ", employees=" + employees +
                '}';
    }

}
Department

resources/mapper(Mapper.xml)

编写sql语句，实现增删改查操作

  • Employee1Mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.djh.demo.dao.EmployeeDao">

    <resultMap id="employeeMap" type="com.djh.demo.bean.Employee">
        <id property="employee_id" column ="employee_id" />
        <result property="employee_name" column = "employee_name"/>
        <result property="employee_age" column = "employee_age"/>
        <association property="department" javaType="com.djh.demo.bean.Department">
            <id property="department_id" column ="department_id" />
            <result property="department_name" column="department_name"/>
        </association>
    </resultMap>

    <select id="selectid" resultMap="employeeMap">
    SELECT
    e.employee_id,
    e.employee_name,
    e.employee_age,
    d.department_name,
    d.department_id
    FROM
    employee AS e
    INNER JOIN
    department AS d
    ON
    e.department_id = d.department_id
    WHERE
    e.employee_id = #{id}
    </select>

    <select id="selectById" resultType="com.djh.demo.bean.Employee">
        select * from employee where department_id = #{id}
    </select>

    <insert id="saveEmployee">
        insert into
        employee (employee_name, employee_age, department_id)
        value (#{employee_name},#{employee_age},#{department_id})
    </insert>

    <delete id="deleteEmployee">
        delete
        from employee
        where employee_id = #{employee_id}

    </delete>

    <update id="updateEmployee">
        update employee set
        employee_name = #{employee_name},
        employee_age = #{employee_age},
        department_id = #{department_id}
        where
        employee_id = #{employee_id}
    </update>
</mapper>
EmployeeMapper.xml

  • DepartmentMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.djh.demo.dao.DepartmentDao">

    <select id="getall" resultType="com.djh.demo.bean.Department">
        select * from department
    </select>
</mapper>
DepartmentMapper.xml

Dao层（Mapper）

接口

数据库操作

  • EmployeeDao

package com.djh.demo.dao;

import com.djh.demo.bean.Employee;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */
@Mapper
public interface EmployeeDao {
    Employee selectid(Integer id);

    List<Employee> selectById( Integer id);

    void saveEmployee(@Param("employee_name") String employee_name,@Param("employee_age") String employee_age,@Param("department_id") Integer department_id);

    void deleteEmployee(Integer employee_id);

    void updateEmployee(@Param("employee_id") Integer employee_id,@Param("employee_name") String employee_name,@Param("employee_age") Integer employee_age,@Param("department_id") Integer department_id );
}
EmployeeDao

  • DepartmentDao

package com.djh.demo.dao;

import com.djh.demo.bean.Department;
import org.apache.ibatis.annotations.Mapper;


import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */
@Mapper
public interface DepartmentDao {

    List<Department> getall ();

}
DepartmentDao

Service层（Service）

  1. Service(实现业务逻辑)，面向接口编程 ：接口类(多数面向dao)调用Dao方法、 实现类。

  2. 注解要写在实现类上 不能写到接口上，将这个类给spring管理。

Service接口

  • EmployeeService

package com.djh.demo.service;
import com.djh.demo.bean.Employee;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */

public interface EmployeeService {

    List<Employee> selectById( Integer id);

    void saveEmployee ( String employee_name,String employee_age,Integer department_id);

    void deleteEmployee(Integer employee_id);

    void updateEmployee( Integer employee_id,  String employee_name,  Integer employee_age,Integer department_id );
}
EmployeeService

  • DepartmentService

package com.djh.demo.service;

import com.djh.demo.bean.Department;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */
public interface DepartmentService {
    List<Department> getall ();
}
DepartmentService

实现对应Service接口（lmpl）

  • EmployeeServicelmpl

package com.djh.demo.service.impl;

import com.djh.demo.bean.Employee;
import com.djh.demo.dao.EmployeeDao;
import com.djh.demo.service.EmployeeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 * 实现类
 *
 */
@Service
public class EmployeeServiceImpl implements EmployeeService {
    @Autowired
    private EmployeeDao employeeDao;

    @Override
    public List<Employee> selectById(Integer id) {
        return this.employeeDao.selectById(id);
}

    @Override
    public void saveEmployee(String employee_name, String employee_age, Integer department_id) {
            employeeDao.saveEmployee(employee_name,employee_age,department_id);
    }

    @Override
    public void deleteEmployee(Integer employee_id) {
        employeeDao.deleteEmployee(employee_id);
    }

    @Override
    public void updateEmployee(Integer employee_id, String employee_name, Integer employee_age ,Integer department_id ) {
            employeeDao.updateEmployee(employee_id,employee_name,employee_age,department_id );
    }

}
EmployeeServicelmpl

  • DepartmentServicelmpl

package com.djh.demo.service.impl;

import com.djh.demo.bean.Department;
import com.djh.demo.dao.DepartmentDao;
import com.djh.demo.service.DepartmentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */
@Service("DepartmentService")
public class DepartmentServicelmpl implements DepartmentService{
    @Autowired
    DepartmentDao departmentDao;


    @Override
    public List<Department> getall() {
        return departmentDao.getall();
    }
}
DepartmentServicelmpl

Controller层

绑定数据、跳转页面、接受用户请求->将数据传到页面

  • EmployeeController

package com.djh.demo.controller;

import com.djh.demo.bean.Department;
import com.djh.demo.bean.Employee;
import com.djh.demo.service.DepartmentService;
import com.djh.demo.service.EmployeeService;
import org.apache.ibatis.annotations.Param;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */
@Controller
public class EmployeeController {
    @Autowired
    private EmployeeService employeeService;

    @Autowired
    private DepartmentService departmentService;

    @GetMapping("/queryEmpByDept")
    public String queryEmpByDept (ModelMap modelMap,Integer department_id){
        List<Employee> employees = employeeService.selectById(department_id);

        modelMap.put("employees",employees);
        modelMap.put("department_id",department_id);

        List<Department> departments = departmentService.getall();
        modelMap.put("departments",departments);

        return "admin";
    }
    @GetMapping("/saveEmployee")
    public String saveEmployee(ModelMap modelMap ,String employee_name , String employee_age , Integer department_id){
        employeeService.saveEmployee(employee_name,employee_age,department_id);

        List<Department> departments = departmentService.getall();

        modelMap.put("departments",departments);

        return "admin";
    }
    
    @GetMapping("/deleteEmployee")
    public String deleteEmployee(Integer employee_id){

        employeeService.deleteEmployee(employee_id);

        return "/admin";
    }
    @GetMapping("/updateEmployee")
    public String updateEmployee(ModelMap modelMap,Integer employee_id , String employee_name , Integer employee_age ,Integer department_id ){
        employeeService.updateEmployee(employee_id,employee_name,employee_age,department_id );
        List<Department> departments = departmentService.getall();
        modelMap.put("departments",departments);
        return "/admin";
    }
}
EmployeeController

  • DepartmentController

package com.djh.demo.service.impl;

import com.djh.demo.bean.Department;
import com.djh.demo.dao.DepartmentDao;
import com.djh.demo.service.DepartmentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author HP
 * @data 2020-12-04
 */
@Service("DepartmentService")
public class DepartmentServicelmpl implements DepartmentService{
    @Autowired
    DepartmentDao departmentDao;


    @Override
    public List<Department> getall() {
        return departmentDao.getall();
    }
}
DepartmentController

 

前端HTML界面

admin（后台界面）

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="queryEmpByDept">
    <select name="department_id">
        <!--/*@thymesVar id="department_id" type=""*/-->
        <option th:each="department: ${departments}"
                th:text="${department.department_name}"
                th:value="${department.department_id}"
                th:selected="${department.department_id}==${department_id}?true:false"></option>
    </select>
    <input type="submit" value="查询">
    <a href="/toadd">添加</a>
    <a href="/toupdate">编辑</a>
</form>

<table border="1" cellpadding="0" cellspacing="0" width="500">
    <thead>
    <tr>
        <th>ID</th>
        <th>姓名</th>
        <th>年龄</th>
        <th>操作</th>
    </tr>
    </thead>
    <tbody>
    <tr th:each="employee : ${employees}">
        <td th:text="${employee .employee_id}"></td>
        <td th:text="${employee .employee_name}"></td>
        <td th:text="${employee .employee_age}"></td>
        <td>
            <a th:href="@{'deleteEmployee'+'?employee_id='+${employee.employee_id}}">删除</a>
            <a th:href="@{'updateEmployee'+'?employee_id='+${employee.employee_id}}"></a>
        </td>
    </tr>
    </tbody>
</table>
</body>
</html>
admin.html

add（增加界面）

<!DOCTYPE html>
<html lang="en"  xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="saveEmployee">
    姓名：<input type="text" name="employee_name" id="employee_name"> <br/>
    年龄：<input type="number" name="employee_age" id="employee_age"> <br/>
    部门：
    <select name="department_id">
        <option th:each="department : ${departments}"
                th:value="${department.department_id}"
                th:text="${department.department_name}"></option>
    </select><br/>
    <input type="submit" value="添加">
</form>
</body>
</html>
add.html

update（编辑界面）

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="updateEmployee">
    职员编号  ：<input type="text" name="employee_id" id="employee_id"> <br/>
    修改姓名  ：<input type="text" name="employee_name" id="employee_name"> <br/>
    修改年龄  ：<input type="text" name="employee_age" id="employee_age"> <br/>
    修改部门  ：
    <select name="department_id">
        <option th:each="department : ${departments}"
                th:value="${department.department_id}"
                th:text="${department.department_name}"></option>
    </select><br/>
    <input type="submit" value="修改">
</form>
</body>
</html>
update.html

 

项目中遇到的问题

1.问题：出现空指针问题，java空指针异常：java.lang.NullPointException

解决方法：实现类或其他类缺少标注@Autowired，接口不需要标注

@Autowired 注释，它可以对类成员变量、方法及构造函数进行标注，完成自动装配的工作。 通过 @Autowired的使用来消除 set ，get方法。

2.问题：进行delete操作时，无法将前页的id数据，导入对应的方法（待完善）

解决办法：试了很多方法都不能解决，前后端数据交接过程存在问题，只能使用拼接url方法将id放入方法中，进行delete操作，使用拼接url可以完成删除操作。

<a th:href="@{'deleteEmployee'+'?employee_id='+${employee.employee_id}}">删除</a>

'deleteEmployee'为指定访问的控制器域名，employee.employee_id为传入的参数id，使用+拼接

3.让部门的下拉列表显示所查询的内容。保持不变

th:selected="${department.department_id}==${department_id}?true:false"

效果：

 若不加，则会显示第一个部门名

项目问题解决及完善办法更新：https://www.cnblogs.com/djhzzl/p/14096824.html

 

posted @ 2020-12-06 14:56  秃头不用洗发水  阅读(298)  评论(0)  编辑  收藏  举报