【spring data jpa】【mybatis】通过反射实现 更新/保存 实体的任意字段的操作

代码如下：

//代码示例：例如保存时，传入下面两个字段

String filed;
String content;

//User代表要更新的实体，user即本对象
//filed代表要更改的字段，例如user.name
//content代表要更改字段的值，例如“张三”

import org.springframework.beans.BeanUtils;

　　　　　　　　　　　　
　　　　　　　　　　　　User user = new User();
　　　　　　　　　　　　//反射赋值
                    //反射 + javaBean机制 get set 方法
                    Class<? extends User> clz = user.getClass();
                    PropertyDescriptor propertyDescriptor = BeanUtils.getPropertyDescriptor(clz, filed);

                    //获取当前字段的javabean写方法
                    Method writeMethod = propertyDescriptor.getWriteMethod();
                    if (writeMethod != null) {
                        try {
                            writeMethod.invoke(user, "张三");
                        } catch (Exception e) {
                            syatem.out.println(e);
                        }
                    }

JPA保存即保存对象即可，因为对象的值已经存入user对象。

User newUser = goodsMsgService.insert(oldGoodsMsg);

mybatis保存对象：

@Update("update goods_msg set ${filed} = #{context} where uid = #{uid}")
    public int saveFiled(@Param("filed")String filed, @Param("uid")String uid, @Param("context")String context);

如下，有一个完整的代码示例可以参考：

//将实体字段存入List

public static final List<String> AUTH_FILEDS = Arrays.asList(new String[]{
            "innerFrist",
            "innerNormal",
            "innerDanger",
            "outFrist",
            "outNormal",
            "outDanger",
            "notAct",
            "share",
            "notSub",
            "exceedMaxQueryTime",
            "scanCodeLimit",
            "innerSafetyTime",
            "outerSafetyTime",
            "scanCodeLimitTime"
    }); 

//将实体属性  对应数据库字段存入 map 方便下面mybatis更新单个字段调用

    public static final Map<String,String> AUTH_FILEDS_MAPPING = new HashMap<>();

    static{
        AUTH_FILEDS_MAPPING.put("innerFrist","inner_frist");
        AUTH_FILEDS_MAPPING.put("innerNormal", "inner_normal");
        AUTH_FILEDS_MAPPING.put("innerDanger", "inner_danger");
        AUTH_FILEDS_MAPPING.put("outFrist", "out_frist");
        AUTH_FILEDS_MAPPING.put("outNormal", "out_normal");
        AUTH_FILEDS_MAPPING.put("outDanger", "out_danger");
        AUTH_FILEDS_MAPPING.put("notAct", "not_act");
        AUTH_FILEDS_MAPPING.put("share", "share");
        AUTH_FILEDS_MAPPING.put("notSub","not_sub");
        AUTH_FILEDS_MAPPING.put("exceedMaxQueryTime", "exceed_max_query_time");
        AUTH_FILEDS_MAPPING.put("scanCodeLimit","scan_code_limit");
        AUTH_FILEDS_MAPPING.put("innerSafetyTime","inner_safety_time");
        AUTH_FILEDS_MAPPING.put("outerSafetyTime","outer_safety_time");
        AUTH_FILEDS_MAPPING.put("scanCodeLimitTime","scan_code_limit_time");
    }

    /**
     * 保存或修改(针对单一字段)
     *
     * ===========================非空字段===========================
     * [
     *     要修改的字段 : filed
     *     字段内容 : context
     *     是否全局 : global (1全局  0不是全局)
     *     绑定的商品或分类 : guid(全局为空)
     * ]
     * ===========================保存逻辑===========================
     *         1 检查要修改的字段是否存在
     *         2 判断操作话述是否属于当前租户
     *         3 判断是否是全局,不是全局guid做非空验证
     *         4 如果已经存在记录则修改   如果不存在新增
     *
     * ===========================安全验证===========================
     * guid是否属于当前租户
     *
     *
     */
    @Override
    public AjaxResult<String> saveFiled(@RequestBody SaveFiledRequestBean requestBean) {
        //当前租户
        TenementUser tenementUser = RequestData.TENEMENT_USER.get();

        //非空
        LunaResultBean.checkField(requestBean,"filed","context","global","name");

        // 不是全局的非空
        if (1 != requestBean.getGlobal()) {
            LunaResultBean.checkField(requestBean,"guid");
        }

        String filed = requestBean.getFiled();
        String guid = requestBean.getGuid();
        String context = requestBean.getContext();

        AjaxResult<String> res = new AjaxResult<String>();

        boolean isAdd = true;
        boolean success = true;
        GoodsMsg oldGoodsMsg = null;
        if(AUTH_FILEDS.contains(filed)){

            if (StringUtils.isNotBlank(guid)) {

                boolean check = goodsConfigUtils.check(GoodsConfigUtils.CHECK_GUID, guid);
                if (check) {

                    // 是否需要新增
                    oldGoodsMsg = goodsMsgService.findByGuid(guid);

                    if (oldGoodsMsg != null) {
                        isAdd = false;

                    }

                } else {
                    success = false;
                }

            } else {
                // 判断全局是否已经存在
                oldGoodsMsg = goodsMsgService.findByGlobalMsg(tenementUser.getTenementId());
                if (oldGoodsMsg != null) {

                    isAdd = false;
                }

            }

            //判断参数验证是否通过
            if (success) {
                if (isAdd) {
                    // 添加
                    oldGoodsMsg = new GoodsMsg();
                    oldGoodsMsg.initInsertData();
                    oldGoodsMsg.setUid(UUID.randomUUID().toString().replaceAll("-", ""));
                    oldGoodsMsg.setGuid(guid);
                    oldGoodsMsg.setGlobal(requestBean.getGlobal());

                    //反射赋值
                    //反射 + javaBean机制 get set 方法
                    Class<? extends GoodsMsg> clz = oldGoodsMsg.getClass();
                    PropertyDescriptor propertyDescriptor = BeanUtils.getPropertyDescriptor(clz, filed);

                    //获取当前字段的javabean写方法
                    Method writeMethod = propertyDescriptor.getWriteMethod();
                    if (writeMethod != null) {
                        try {
                            writeMethod.invoke(oldGoodsMsg, requestBean.getContext());
                        } catch (Exception e) {
                            throw new LunaException("方法 "+ writeMethod.getName() +"无法执行",AjaxResult.ERROR_SYS_EXCPTION);
                        }
                    }

                    //新增
                    GoodsMsg insert = goodsMsgService.insert(oldGoodsMsg);
                    if (insert != null) {
                        res.initTrue("操作成功");
                    } else {
                        res.initFalse("操作失败", LunaResultBean.ERROR_BUSINESS);
                    }

                } else {
                    //修改
                    //调用mybatis   update 字段 by uid
                    int saveFiled = goodsMsgService.saveFiled(AUTH_FILEDS_MAPPING.get(filed), oldGoodsMsg.getUid(), context);

                    if(saveFiled > 0){
                        res.initTrue("操作成功");
                    } else {
                        res.initFalse("操作失败", LunaResultBean.ERROR_BUSINESS);
                    }
                }

            } else {
                res.initFalse("请选择正确的商品或商品类型", LunaResultBean.ERROR_BUSINESS);
            }

        }else{
            res.initFalse("无效字段 ["+ filed +"]", LunaResultBean.ERROR_BUSINESS);
        }

        return res;
    }