IPage外部原理也是基于拦截器，然而这个拦挡的是办法以及办法中的参数，这个也会判断是否是查问操作。 如果是查问操作，才会进入分页的解决逻辑。 进入分页逻辑解决后，拦截器会通过反射获取该办法的参数 进行判断是否存在IPage对象的实现类。如果不存在则不进行分页，存在则将该参数赋值给IPage对象。 而后进行拼接sql的解决实现分页操作。 然而应用IPage须要注入一个bean拦截器交给spring进行治理。如下。否则不会进行拦挡

  1. 注入paginationInterceptor 分页bean
@Bean
public PaginationInterceptor paginationInterceptor() {
return new PaginationInterceptor();
}
  1. 拦挡源码
public Object intercept(Invocation invocation) throws Throwable {        StatementHandler statementHandler = PluginUtils.realTarget(invocation.getTarget());     MetaObject metaObject = SystemMetaObject.forObject(statementHandler);     // SQL 解析     this.sqlParser(metaObject);     // 先判断是不是SELECT操作  (2019-04-10 00:37:31 跳过存储过程)     MappedStatement mappedStatement = (MappedStatement) metaObject.getValue("delegate.mappedStatement");     if (SqlCommandType.SELECT != mappedStatement.getSqlCommandType()            || StatementType.CALLABLE == mappedStatement.getStatementType()) {            return invocation.proceed();     }        // 针对定义了rowBounds，做为mapper接口办法的参数     BoundSql boundSql = (BoundSql) metaObject.getValue("delegate.boundSql");     Object paramObj = boundSql.getParameterObject();     // 判断参数里是否有page对象     IPage<?> page = null;     if (paramObj instanceof IPage) {            page = (IPage<?>) paramObj;     } else if (paramObj instanceof Map) {            for (Object arg : ((Map<?, ?>) paramObj).values()) {                if (arg instanceof IPage) {                    page = (IPage<?>) arg;     break; }            }        }        /*     * 不须要分页的场合，如果 size 小于 0 返回后果集 */ if (null == page || page.getSize() < 0) {            return invocation.proceed();     }        if (this.limit > 0 && this.limit <= page.getSize()) {            //解决单页条数限度     handlerLimit(page);     }        String originalSql = boundSql.getSql();     Connection connection = (Connection) invocation.getArgs()[0];     if (page.isSearchCount() && !page.isHitCount()) {            SqlInfo sqlInfo = SqlParserUtils.getOptimizeCountSql(page.optimizeCountSql(), countSqlParser, originalSql);     this.queryTotal(sqlInfo.getSql(), mappedStatement, boundSql, page, connection);     if (page.getTotal() <= 0) {                return null;     }        }        DbType dbType = Optional.ofNullable(this.dbType).orElse(JdbcUtils.getDbType(connection.getMetaData().getURL()));     IDialect dialect = Optional.ofNullable(this.dialect).orElse(DialectFactory.getDialect(dbType));     String buildSql = concatOrderBy(originalSql, page);    //执行物理分页    DialectModel model = dialect.buildPaginationSql(buildSql, page.offset(), page.getSize());     Configuration configuration = mappedStatement.getConfiguration();     List<ParameterMapping> mappings = new ArrayList<>(boundSql.getParameterMappings());     Map<String, Object> additionalParameters = (Map<String, Object>) metaObject.getValue("delegate.boundSql.additionalParameters");     model.consumers(mappings, configuration, additionalParameters);     metaObject.setValue("delegate.boundSql.sql", model.getDialectSql());     metaObject.setValue("delegate.boundSql.parameterMappings", mappings);     return invocation.proceed();    }

参考博客
`https://blog.csdn.net/xiaolegeaizy/article/details/108461284