SpringBoot--页面显示列表功能

水深无声 2023-09-27 08:53 132阅读 0赞

**功能介绍：** 用于在table中渲染出数据库中的数据。

**1、IDEA进行相关的配置，并且创建SpringBoot项目，目录如下：**  
![在这里插入图片描述][899f0d151d054bb88e3e7777d13d9cc4.png]  
**2、domain中创建实体类，用于和数据库中的数据表关联起来，User。**

package com.example.demo.domain;
    
    public class User {
        
        // 对应数据表user中的各字段
        private String uuid;
        private String username;
        private String gender;
        private int age;
        private String phone;
        private String address;
        private String email;
        private float salary;
    
        // 鼠标右键选择generate，接着选择setter and getter，选中所有字段，然后点击Ok，便会自动为我们自动生成get和set方法。
        public String getUuid() {
        
            return uuid;
        }
        public void setUuid(String uuid) {
        
            this.uuid = uuid;
        }
    
        public String getUsername() {
        
            return username;
        }
        public void setUsername(String username) {
        
            this.username = username;
        }
    
        public String getGender() {
        
            return gender;
        }
        public void setGender(String gender) {
        
            this.gender = gender;
        }
    
        public int getAge() {
        
            return age;
        }
        public void setAge(int age) {
        
            this.age = age;
        }
    
        public String getPhone() {
        
            return phone;
        }
        public void setPhone(String phone) {
        
            this.phone = phone;
        }
    
        public String getAddress() {
        
            return address;
        }
        public void setAddress(String address) {
        
            this.address = address;
        }
    
        public String getEmail() {
        
            return email;
        }
        public void setEmail(String email) {
        
            this.email = email;
        }
    
        public float getSalary() {
        
            return salary;
        }
        public void setSalary(float salary) {
        
            this.salary = salary;
        }
    }

**3、mapper中创建接口（interface），如：UserMapper。**

package com.example.demo.mapper;
    
    import com.example.demo.domain.User;
    import org.apache.ibatis.annotations.*;
    import java.util.List;
    
    public interface UserMapper {
        
        // 与数据库相关的操作，通过注解来实现
        // 查询所有数据在列表中
        @Select("select * from user")
        @Results({
        @Result(column = "username",property = "username")})  // MyBatis中使用@Results注解来映射查询结果集到实体类属性，column为数据库字段名，porperty为实体类属性名。
        public List<User> findAll();  // 创建一个findAllUser（）方法，返回类型是list，list元素类型是User。
    }

**4、service中创建服务（对应着mapper中的接口），如：UserService。**

package com.example.demo.service;
    
    import com.example.demo.domain.User;
    import com.github.pagehelper.PageInfo;
    import java.util.List;
    
    public interface UserService {
        
        // 简单分页查询
        PageInfo<User>findAllSimplePage(int page,int size);
    }

**5、service-impl中创建接口服务的实现（对应着service中的接口），如：UserServiceImpl。**

package com.example.demo.service.impl;
    
    import com.example.demo.domain.User;
    import com.example.demo.mapper.UserMapper;
    import com.example.demo.service.UserService;
    import com.github.pagehelper.PageHelper;
    import com.github.pagehelper.PageInfo;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import javax.annotation.Resource;
    import java.util.List;
    
    @Service("UserService")
    public class UserServiceImpl implements UserService {
        
        @Resource  // 接口只能有一个实现类（@Resource是JDK提供的，通过name名字查找；而Autowired是Spring提供的，通过type类型查找。）
        private UserMapper userMapper;
    
        // 鼠标放在public class UserServiceImpl implements UserService的红线处，点击implement methods，全部选中，则创建好了所有的方法
        // 简单的分页查询
        @Override
        public PageInfo<User> findAllSimplePage(int page, int size) {
        
            // 利用PageHelper插件做分页查询.page是从1开始
            PageHelper.startPage(page,size);
            List<User> users = userMapper.findAll();
            PageInfo<User> pageInfo = new PageInfo<>(users);
            return pageInfo;
        }
    }

**6、controller中创建控制器，如：UserController。**

package com.example.demo.controller;
    
    import com.alibaba.fastjson.JSONObject;
    import com.example.demo.domain.User;
    import com.example.demo.service.UserService;
    import com.github.pagehelper.PageInfo;
    import netscape.javascript.JSObject;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.*;
    import javax.annotation.Resource;
    import java.util.*;
    
    @Controller  // ①返回JSON或XML数据；②页面模板
    @RequestMapping("/user")  // 这个类的路径，定义为/user
    public class UserController {
        
        @Resource(name = "UserService")
        private UserService csi;
    
        @RequestMapping("findAllSimplePage")
        @ResponseBody
        // @RequestBody(required=false) 表示map对象可以不传入
        // @RequestBody(required = false) Map<String,Object> 客户端的可以不传入这段参数，也可以正常的运行
        public String findAllSimplePage(@RequestParam(value = "page", defaultValue = "3") Integer page,
                                        @RequestParam(value = "size", defaultValue = "5") Integer size){
        
            Map<String, Object> requestMap  = new HashMap<String, Object>();
            requestMap .put("page", page);
            requestMap .put("size", size);
    
            if (requestMap != null){
        
                if (requestMap.get("page").toString() != null){
        
                    page = Integer.parseInt(requestMap.get("page").toString());  // Integer.parseInt是Integer类中提供的一个静态方法,用于将传入的string类型字符串根据要求转为相应进制的int值, 如果没有要求进制则按10进制计算
                    page = page-1; // 为了使页面从第一页开始查询
                }
                if (requestMap.get("size").toString() != null){
        
                    size = Integer.parseInt(requestMap.get("size").toString());
                }
            }
    
            PageInfo<User> pageInfo = csi.findAllSimplePage(page,size);
            List<User> users = pageInfo.getList();   // 等待dump
            long total = pageInfo.getTotal();        // 一共多少条数据
            JSONObject result = new JSONObject();    // JSONObject-lib包是一个beans,collections,maps,java arrays和xml和JSON互相转换的包,将实体对象转换成Json字符串。
            result.put("rows",users);                // rows表示每一条数据的详细记录
            result.put("total",(int)total);          // 一共多少条数据
            return result.toJSONString();  // toJSONString()默认忽略值为null的属性，本返回值中并未返回page和size分页的结果，而是将所有的数据一把抓地传送到前端，具体的分页效果还是根据前端设置。
        }
    
    }

**效果展示：**  
![在这里插入图片描述][fdfed50d42124086b7809887fbd1e744.png]

**相关链接：**  
[IntelliJ IDEA中构建Spring Boot的项目][IntelliJ IDEA_Spring Boot]  
[Spring Boot中的配置文件（application.properties、application.yml与pom.xml）][Spring Boot_application.properties_application.yml_pom.xml]  
[ORM、JPA、Spring Data JPA和常用的五种访问数据库方式][ORM_JPA_Spring Data JPA]

[SpringBoot–页面显示列表功能][SpringBoot]  
[SpringBoot–列表添加详情功能][SpringBoot 1]  
[SpringBoot–列表添加新增功能][SpringBoot 2]  
[SpringBoot–列表更新功能][SpringBoot 3]  
[SpringBoot–列表删除功能][SpringBoot 4]

[SpringBoot的控制层注解(@Controller与@RestController)][SpringBoot_Controller_RestController]  
[SpringBoot的业务层注解(@Resource、@Autowired与@Qualifier)][SpringBoot_Resource_Autowired_Qualifier]  
[SpringBoot的映射（@RequestMapping、@GetMapping与@PostMapping）][SpringBoot_RequestMapping_GetMapping_PostMapping]  
[SpringBoot的函数参数（JavaBean对象、@RequestParam与@RequestBody）][SpringBoot_JavaBean_RequestParam_RequestBody]  
[SpringBoot的返回数据（@ResponseBody、返回templates下的网页 与 返回公共网页）][SpringBoot_ResponseBody_templates_ _]

[利用postman完成JSON串的发送功能（springboot）][postman_JSON_springboot]  
[利用postman完成数据的分页查询功能（springboot）][postman_springboot]  
[利用postman完成向数据库中添加数据的功能（springboot）][postman_springboot 1]

[Please refer to dump files (if any exist) \[date\].dump, \[date\]-jvmRun\[N\].dump and \[date\].dumpstream.][Please refer to dump files _if any exist_ _date_.dump_ _date_-jvmRun_N_.dump and _date_.dumpstream.]  
[Preparing: insert into user(uuid,username,gender,age,phone,address) values(?,?,?,?,?,?,?)][Preparing_ insert into user_uuid_username_gender_age_phone_address_ values]  
[Could not autowire. No beans of ‘UserMapper‘ type found.][Could not autowire. No beans of _UserMapper_ type found.]  
[Error starting ApplicationContext. To display the conditions report re-run your application with][]  
[Loading class `com.mysql.jdbc.Driver‘. This is deprecated. The new driver class is`com.mysql.cj.jdb][Loading class _com.mysql.jdbc.Driver_. This is deprecated. The new driver class is_com.mysql.cj.jdb]  
[Plugin ‘org.springframework.boot:spring-boot-maven-plugin:‘ not found][Plugin _org.springframework.boot_spring-boot-maven-plugin_ not found]  
[Failed to configure a DataSource: ‘url‘ attribute is not specified and no embedded datasource could][Failed to configure a DataSource_ _url_ attribute is not specified and no embedded datasource could]  
[This application has no explicit mapping for /error, so you are seeing this as a fallback.][This application has no explicit mapping for _error_ so you are seeing this as a fallback.]  
[BootStrap-SpringBoot的使用过程中前端table表格无法加载出数据。][BootStrap-SpringBoot_table]

[899f0d151d054bb88e3e7777d13d9cc4.png]: https://img-blog.csdnimg.cn/899f0d151d054bb88e3e7777d13d9cc4.png
[fdfed50d42124086b7809887fbd1e744.png]: https://img-blog.csdnimg.cn/fdfed50d42124086b7809887fbd1e744.png
[IntelliJ IDEA_Spring Boot]: https://blog.csdn.net/blbyu/article/details/126745392
[Spring Boot_application.properties_application.yml_pom.xml]: https://blog.csdn.net/blbyu/article/details/126747098
[ORM_JPA_Spring Data JPA]: https://blog.csdn.net/blbyu/article/details/126739840
[SpringBoot]: https://blog.csdn.net/blbyu/article/details/126749514
[SpringBoot 1]: https://blog.csdn.net/blbyu/article/details/126749700
[SpringBoot 2]: https://blog.csdn.net/blbyu/article/details/126749722
[SpringBoot 3]: https://blog.csdn.net/blbyu/article/details/126749745
[SpringBoot 4]: https://blog.csdn.net/blbyu/article/details/126760296
[SpringBoot_Controller_RestController]: https://blog.csdn.net/blbyu/article/details/126744746
[SpringBoot_Resource_Autowired_Qualifier]: https://blog.csdn.net/blbyu/article/details/126744825
[SpringBoot_RequestMapping_GetMapping_PostMapping]: https://blog.csdn.net/blbyu/article/details/126744866
[SpringBoot_JavaBean_RequestParam_RequestBody]: https://blog.csdn.net/blbyu/article/details/126744903
[SpringBoot_ResponseBody_templates_ _]: https://blog.csdn.net/blbyu/article/details/126744442
[postman_JSON_springboot]: https://blog.csdn.net/blbyu/article/details/126533207
[postman_springboot]: https://blog.csdn.net/blbyu/article/details/126533491
[postman_springboot 1]: https://blog.csdn.net/blbyu/article/details/126532840
[Please refer to dump files _if any exist_ _date_.dump_ _date_-jvmRun_N_.dump and _date_.dumpstream.]: https://blog.csdn.net/blbyu/article/details/126497411
[Preparing_ insert into user_uuid_username_gender_age_phone_address_ values]: https://blog.csdn.net/blbyu/article/details/126532138
[Could not autowire. No beans of _UserMapper_ type found.]: https://blog.csdn.net/blbyu/article/details/126532911
[Error starting ApplicationContext. To display the conditions report re-run your application with]: https://blog.csdn.net/blbyu/article/details/126468130
[Loading class _com.mysql.jdbc.Driver_. This is deprecated. The new driver class is_com.mysql.cj.jdb]: https://blog.csdn.net/blbyu/article/details/126588912
[Plugin _org.springframework.boot_spring-boot-maven-plugin_ not found]: https://blog.csdn.net/blbyu/article/details/126589582
[Failed to configure a DataSource_ _url_ attribute is not specified and no embedded datasource could]: https://blog.csdn.net/blbyu/article/details/126595381
[This application has no explicit mapping for _error_ so you are seeing this as a fallback.]: https://blog.csdn.net/blbyu/article/details/126595503
[BootStrap-SpringBoot_table]: https://blog.csdn.net/blbyu/article/details/126624043