初尝试-前端layui后端ssm 管理后台

遇到问题记录

1.查看所有文章  前端layui自动发起请求

Request URL: http://localhost:8080/content/findAll.do?page=1&limit=10

后端 Controller 接收请求，调Service层，Service调Dao层

@Controller
@RequestMapping("content")
public class ContentController {
    private static final Logger logger = org.apache.log4j.Logger.getLogger(ContentController.class);
    @Autowired
    private ContentService contentService;
     /*查看所有文章*/
    @RequestMapping("/findAll.do")
    @ResponseBody
    public LayuiData findAll(Integer page,Integer limit){

        Limit lt = new Limit(page,limit);

        List<Content> all = contentService.findAll(lt);
        Integer many = contentService.findMany(page,limit);
        logger.info("page============>"+page);
        logger.info("limit============>"+limit);
        logger.info("many============>"+many);

        LayuiData ld = new LayuiData(0,"成功了",many,all);
        return ld;
    }
}

Dao层 有个小坑 开始没有封装Limit类，传了两个参数给findAll，结果一直报错 

"Parameter 'XXX' not found. Available parameters are [arg1, arg0, param1,..."

后查资料参考 得知 传多个参数要加注解 @Param("xxx")

https://blog.csdn.net/xuanbabyliu/article/details/84374872

 //public List<Content> findAll(@Param("page") Integer page, @Param("limit") Integer limit);
    public List<Content> findAll(Limit lt);

于是封装了一个类，专门接收分页，虽然感觉没必要 不过就当试验练习了

public class Limit {
    private Integer page;
    private Integer limit;
    public Integer getPage() {
        return page;
    }
    public void setPage(Integer page) {
        this.page = page;
    }
    public Integer getLimit() {
        return limit;
    }
    public void setLimit(Integer limit) {
        this.limit = limit;
    }
    public Limit(Integer page, Integer limit) {
        this.page = page;
        this.limit = limit;
    }
    public Limit() {
    }
}

2.删除+批量删除（说是删除 实际只是修改了数据库del字段）   前端ajax发起请求  

//发送ajax请求
                var url = "/content/delByid.do";
                var params = {"id" : data.id};
                $.ajax({
                    url:url,
                    data:JSON.stringify(params),
                    //data:'{"username":"liangge", "password":"123", "age":18}',或者这样写也可以，不用序列化，直接写的规范一点
                    type:"post",
                    success:function (resultData) {
                        //成功后的回调函数
                        console.log(resultData);
                            tableIns.reload();
                            layer.close(index);
                    },
                    dataType:"json",
                    contentType: 'application/json;charset=UTF-8'
                });

因为是单个删除，后端要接受传过来的一个id，不知道有什么简单的方法接收只有一个键值对的json,最后还是用的封装的实体类（开始想用HttpServletRequest的getParameter方法，但是没有接收到，参考文章 https://blog.csdn.net/shuangmulin45/article/details/78083992）

https://blog.csdn.net/weixin_39220472/article/details/80725574

  /*    逻辑删除*/
    @RequestMapping(path = "/delByid.do")
    @ResponseBody
    public LayuiData delById(@RequestBody Content content){
        Integer id = content.getId();
        logger.info("id============>"+id);
        Integer rs = contentService.delByid(id);
        LayuiData ld = new LayuiData();
        if (rs == 1){
            ld.setCode(1);
            ld.setMsg("成功了");
            return ld;
        }else {
            ld.setCode(0);
            ld.setMsg("失败了");
            return ld;
        }
    }

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批量删除 layui前端ajax发起请求

//批量删除 

 var newsId = [];
        if(data.length > 0) {
            for (var i in data) {
                newsId.push(data[i].id);
            }

$.ajax({
                    type:"post",
                    url:"/content/delByids.do",
                    contentType:"application/json",
                    data:JSON.stringify(newsId),
                    success:function (rs) {
                        console.log(rs);
                        tableIns.reload();
                        layer.close(index);
                    }
                })

因为是个数组 所以后端接收有个小细节  后端接收 接收json数组 

查资料参考的 https://blog.csdn.net/u012838207/article/details/80519375

 /*    批量逻辑删除*/
    @RequestMapping("/delByids.do")
    @ResponseBody
    public LayuiData delByids(@RequestBody String[] array){
        List al = new ArrayList();
        LayuiData ld = new LayuiData();
        for (String a:array
             ) {
            logger.info("a============>"+a);

            Integer i = contentService.delByid(Integer.parseInt(a));
            al.add(i);
        }
        if (al.size() >=1 ){
            ld.setCode(1);
            ld.setMsg("成功了");
        }else{
            ld.setCode(0);
            ld.setMsg("失败了");
        }

        return ld;
    }