mybatisPlus自定义拦截器

一开始数据库的数据是明文存储，后面某些数据需要变成密文保存在数据库，而且密文的字段在很多数据表中都存在。进行select操作时，把密文查询出来并转成明文。
1、使用切面，当接口获取到数据后，遍历数据找到密文字段，把密文解密得到明文
2、使用mybatisPlus自定义拦截器，在sql语句执行前拦截，把 字段 改成 IFNULL(AES_DECRYPT(UNHEX(字段), 密码),字段) AS 字段，sql语句可以解密得到明文。
下面是mybatisPlus自定义拦截器的代码：

@EnableTransactionManagement@Configurationpublic class MybatisPlusConfig {    @Resource    private DataScopeInterceptor dataScopeInterceptor;    @Bean    public MybatisPlusInterceptor mybatisPlusInterceptor() {        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();        // 数据权限过滤        interceptor.addInnerInterceptor(dataScopeInterceptor);        return interceptor;    }}

@Componentpublic class DataScopeInterceptor implements InnerInterceptor {private static Set selectItemSet = new HashSet<>();    @Override    public void beforeQuery(Executor executor, MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) {        String buildSql = boundSql.getSql();        try {            Statement statement = CCjsqlParserUtil.parse(buildSql);            Select select = (Select) statement;            processSelectBody(select.getSelectBody());            PluginUtils.MPBoundSql mpBoundSql = PluginUtils.mpBoundSql(boundSql);            mpBoundSql.sql(select.toString());        } catch (JSQLParserException e) {            throw ExceptionUtils.mpe("Failed to process, Error SQL: %s", e.getCause(), buildSql);        } catch (BaseBusinessException be) {            log.warn(be.getMessage());        }    }    private void processSelectBody(SelectBody selectBody) throws BaseBusinessException, JSQLParserException {        if (selectBody == null) {            throw new BaseBusinessException(ResponseCodeEnum.IGNORE_DATA_SCOPE);            // return;        }        if (selectBody instanceof PlainSelect) {            processPlainSelect((PlainSelect) selectBody);        } else if (selectBody instanceof WithItem) {            WithItem withItem = (WithItem) selectBody;            processSelectBody(withItem.getSelectBody());        } else {            SetOperationList operationList = (SetOperationList) selectBody;            List selectBodys = operationList.getSelects();            if (CollectionUtils.isNotEmpty(selectBodys)) {                for (SelectBody body : selectBodys) {                    processSelectBody(body);                }            }        }    }    private void proprocessPlainSelect(PlainSelect plainSelect) throws JSQLParserException {        if(selectItemSet.size()>0) selectItemSet = new HashSet<>();        FromItem fromItem = plainSelect.getFromItem();        List joins = plainSelect.getJoins();        processSelectColumns(plainSelect, fromItem);        if (CollectionUtils.isNotEmpty(joins)) {            for (Join join : joins) {                if (join.isInner() || join.isFull() || join.isSimple()) {                    FromItem rightItem = join.getRightItem();                    processSelectColumns(plainSelect, rightItem);                } else if (join.isLeft()) {                    FromItem rightItem = join.getRightItem();                    processSelectColumns(plainSelect, rightItem);                } else if (join.isRight()) {                    FromItem rightItem = join.getRightItem();                    processSelectColumns(plainSelect, rightItem);                }            }        }        if (selectItemSet.size() == 0) return;        List filterItem = new ArrayList<>();        List selectItemList=selectItemSet.stream()                .filter(e -> {                    boolean found = !filterItem.contains(e.toString());                    filterItem.add(e.toString());                    return found;                })                .collect(Collectors.toList());        if (selectItemList.size() > 0) {            plainSelect.setSelectItems(selectItemList);        }    }    // select时解密； *号根据具体的表替换成具体的字段    private void processSelectColumns(PlainSelect plainSelect, FromItem fromItem) {    if (! (fromItem instanceof Table)) return;        Table table = (Table) fromItem;        for (SelectItem selectItem : plainSelect.getSelectItems()) {        // 1、做判断，不是需要解密的字段和*号就直接add        // 2、是需要解密的字段，则变成IFNULL(AES_DECRYPT(UNHEX(字段), 密码),字段) AS 字段，再add        // 3、*号则转换成具体的表字段，遍历表字段，是需要解密的字段则转换后add，不是就直接add。add前需要把字段String变成selectItem        // 最后。 sql语句会出现 table b；b.id bid、b.id、id；等情况，根据实际情况判断        selectItemSet.add(selectItem);        }    }

来源地址：https://blog.csdn.net/weixin_43381157/article/details/126764495