项目7-音乐播放器6+评论区

1.准备前端界面

前端小白：怎么为你的网页增加评论功能？（一）_为网页添加评论区怎么弄-CSDN博客

参考的上述文章的前端代码

我们从上述前端图片知道，我们数据库需要准备的字段：

id,commentuserName,coomentmusicId,comment,time

2.数据库的准备

DROP TABLE IF EXISTS `commentmusic`;
CREATE TABLE `commentmusic` (
`id` int PRIMARY KEY AUTO_INCREMENT,
`commentuser_name` varchar(20) NOT NULL,
`commentmusic_id` int(11) NOT NULL,
`commenttime` DATETIME DEFAULT now(),
`comment` varchar(100) NOT NULL
);

3.提交评论数据

路径："/comment/upload"

3.1 后端代码书写

1.MAPPER

@Mapper
public interface CommentMapper {
    @Insert("insert into commentmusic(commentmusic_id,commentuser_name,comment) values " +
            "(#{commentmusicId},#{commentuserName},#{comment})")
    Integer insertComment(Integer commentmusicId,String commentuserName,String comment);
}

2.SERVICE

@Service
@Slf4j
public class CommentService {
    @Autowired
    private CommentMapper commentMapper;
    @Autowired
    private MusicMapper musicMapper;
    public Result insertComment(Integer commentmusicId, String commentuserName, String comment){
        Comment commentable=new Comment();
        if(!StringUtils.hasLength(comment)){
            return Result.fail(Constant.RESULT_CODE_NO_CHOICE,"评论不能为空");
        }else if(musicMapper.selectByMusicId(commentmusicId)==null){
            return Result.fail(Constant.RESULT_CODE_NOTMP3_DELETEFAIL,"没有该音乐");
        }
        Integer factor=commentMapper.insertComment(commentmusicId,commentuserName,comment);
        if(factor<1){
            return Result.fail(Constant.RESULT_CODE_FAIL_SQL,"数据库插入失败");
        }
        commentable.setComment(comment);
        commentable.setCommentmusicId(commentmusicId);
        commentable.setCommentuserName(commentuserName);
        return Result.success(true);
    }
}

3.Controller

@RestController
@RequestMapping("/comment")
public class CommentController {
    @Autowired
    private CommentService commentService;
    @RequestMapping("/upload")
    public Result insertComment(Integer commentmusicId, String comment, HttpSession httpSession){
        //获得当前的用户名
        User user= (User) httpSession.getAttribute(Constant.USERINFO_SESSION_KEY);
        String commentuserName=user.getUsername();
        return commentService.insertComment(commentmusicId, commentuserName, comment);
    }
}

3.2 后端测试

4.评论页面展示

4.1 后端代码书写

MAPPER

@Select("select * from commentmusic where commentmusic_id=#{commentmusicId}")
List<Comment> selectAllComment(Integer commentmusicId);

SERVICE

public Result selectAllComment(Integer commentmusicId){
    return Result.success(commentMapper.selectAllComment(commentmusicId));
}

CONTROLLER

@RequestMapping("/list")
public Result selectAllComment(Integer commentmusicId){
    return Result.success(commentService.selectAllComment(commentmusicId));
}

4.2 后端测试

成功！！！

5.SECTION3和SECTION4的前端代码书写

前端测试成功！！！

想加入删除评论的功能

这时候我们要让前端获取一些值，后端增加方法

@RequestMapping("/view")
public Result InsertUserInfo(HttpSession httpSession){
    User user=(User) httpSession.getAttribute(Constant.USERINFO_SESSION_KEY);
    return Result.success(user.getUsername());
}

前端的书写

$(function(){

$.ajax({

type: "get",

url: "/user/view",

success: function(result){

if(result.status==200){

var userName=result.data;

load(userName);

}

}

})

});

function load(userName){

$.ajax({

type: "get",

url: "/comment/list"+location.search,

success: function(result){

if(result!=null&&result.status==200){

var data=result.data;

for(var i = 0; i < data.length;i++) {

var deleteflag='<td> <button class = "btn btn-primary" οnclick="deleteInfo('+data[i].id+')"> 删除 </button>';

var value= data[i].comment+" ";

var p= document.createElement("p");

if(data[i].commentuserName==userName){

p.innerHTML="用户："+data[i].commentuserName+'<hr>'+value+'<hr>'+data[i].commenttime+' '+deleteflag;

}else{

p.innerHTML="用户："+data[i].commentuserName+'<hr>'+value+'<hr>'+data[i].commenttime;

}

document.getElementById("commend").prepend(p);

}

}

},

error: function(error){

if(error!=null&&error.status==401){

alert("请登录用户");

location.href = "login.html";

}

}

});

}

function send(){

$.ajax({

type: "get",

url: "/comment/upload"+location.search,

data:{

comment: $("#typing").val()

},

error: function(error){

if(error!=null&&error.status==401){

alert("请登录用户");

location.href = "login.html";

}

},

success: function(result){

location.reload();

}

});

}

此时，自己写的评论可以看到删除按钮

5.1 完成删除评论的功能

@RequestMapping("/delete")
public Result deleteComment(Integer id){
    return commentService.deleteComment(id);
}

function deleteInfo(id){

$.ajax({

type: "get",

url: "/comment/delete",

data:{

id: id,

},

success: function(result){

if(result.status==200){

alert("删除评论成功");

location.reload();

}

}

});

}