从数据库获取数据转成json格式-java后端

先上代码

private JSONArray getJsonArray(){
        QueryWrapper<KltSoftExamineEntity> kltSoftExamineQueryWrapper=new QueryWrapper<>();
        kltSoftExamineQueryWrapper.select("platform").groupBy("platform");
        List<KltSoftExamineEntity> platForms=kltSoftExamineMapper.selectList(kltSoftExamineQueryWrapper);
        JSONArray jsonArray=new JSONArray();
        JSONObject jsonPlatObject =new JSONObject();
        platForms.forEach(platForm->{
            jsonPlatObject.put("plateformCode",platForm.getPlatform());//1
            jsonPlatObject.put("plateformName","platformName");//2
            //获取serverList
            JSONArray jsonServerListArray=new JSONArray();
            QueryWrapper<KltSoftExamineEntity> kltSoftExamineQueryWrapper1=new QueryWrapper<>();
            kltSoftExamineQueryWrapper1.select("server_ip").groupBy("server_ip").eq("platform",platForm.getPlatform());
            List<KltSoftExamineEntity> serverIps=kltSoftExamineMapper.selectList(kltSoftExamineQueryWrapper1);
            JSONObject jsonServerObject =new JSONObject();
            AtomicInteger i= new AtomicInteger();
            serverIps.forEach(serverIp->{
                jsonServerObject.put("serverName","licens-server"+i);//2.1
                i.getAndIncrement();
                jsonServerObject.put("serverIp",serverIp.getServerIp());//2.2

                //获取softList
                JSONArray jsonSoftListArray=new JSONArray();
                QueryWrapper<KltSoftExamineEntity> kltSoftExamineQueryWrapper2=new QueryWrapper<>();
                kltSoftExamineQueryWrapper2.select("soft_name").groupBy("soft_name").eq("server_ip",serverIp.getServerIp());
                List<KltSoftExamineEntity> softNames=kltSoftExamineMapper.selectList(kltSoftExamineQueryWrapper2);
                JSONObject jsonSoftObject =new JSONObject();
                softNames.forEach(softName->{
                    jsonSoftObject.put("softName",softName.getSoftName());//3.1

                    //获取featureList
                    JSONArray jsonFeatureListArray=new JSONArray();
                    QueryWrapper<KltSoftExamineEntity> kltSoftExamineQueryWrapper3=new QueryWrapper<>();
                    kltSoftExamineQueryWrapper3.select("feature_name").groupBy("feature_name").eq("soft_name",softName.getSoftName());
                    List<KltSoftExamineEntity> featureNames=kltSoftExamineMapper.selectList(kltSoftExamineQueryWrapper3);
                    featureNames.forEach(featureName->{
                        JSONObject jsonFeatureObject =new JSONObject();
                        jsonFeatureObject.put("featureName",featureName.getFeatureName());//4.1
                        jsonFeatureListArray.add(jsonFeatureObject);
                    });
                    jsonSoftObject.put("featureList",jsonFeatureListArray);//3.2
                    jsonSoftListArray.add(jsonSoftObject);
                });
                jsonServerObject.put("softList",jsonSoftListArray);//2.3
                jsonServerListArray.add(jsonServerObject);

            });
            //serverList是JSONArray
            jsonPlatObject.put("serverList",jsonServerListArray);//3
            jsonArray.add(jsonPlatObject);
        });
        return jsonArray;
    }

上述对数据库的操作都是在一张表上面取的

思路

1. 根据查询的字段再回表查询
2. 为了防止查询的数据重复，用到了groupby()函数

全部都是自己手写的，虽然多层嵌套，方法笨笨的，但是好有成就感！