hbase2.1.x java SingleColumnValueFilter 列不存在时，无法过滤，满足所有过滤条件 作者：马育民 • 2021-11-29 19:04 • 阅读：10233 # 描述问题 ### 添加测试数据 清空表： ``` truncate 'book' ``` 添加数据： ``` put 'book','1001','c1:title','htlm从入门到放弃' put 'book','1001','c1:author','lucy' put 'book','1002','c1:title','css从入门到放弃' put 'book','1002','c1:author','lili' put 'book','1002','c1:price','099.90' put 'book','1003','c1:title','hadoop从入门到放弃' put 'book','1003','c1:author','韩梅梅' put 'book','1003','c1:price','190.00' put 'book','1003','c1:title','hbase从入门到精通' put 'book','1003','c1:author','李雷' put 'book','1003','c1:price','029.50' ``` **注意：** `rowkey` 是 `1001` 的记录，没有 `price` ### 代码 上接：[hbase2.1.x java SingleColumnValueFilter 过滤](https://www.malaoshi.top/show_1IX1x6mGCLUf.html "hbase2.1.x java SingleColumnValueFilter 过滤") ### 测试1： ``` hu.filter("book", "c1", "price", CompareOperator.EQUAL, "099.90"); ``` **查询结果：** ``` 1001 c1:author:lucy c1:title:htlm从入门到放弃 ------------------ 1002 c1:author:lili c1:price:099.90 c1:title:css从入门到放弃 ``` **原因：**因为 `rowkey 是 1001` 的记录 没有 `age` ，在 hbase 中，默认 **满足所有过滤条件** ### 测试2： 列名写错了，写成大写的 `PRICE` ``` hu.filter("book", "c1", "PRICE", CompareOperator.EQUAL, "099.90"); ``` **查询出所有结果** **原因：**在 hbase 中，默认 **满足所有过滤条件** # 解决 ### 关键代码 ``` filter.setFilterIfMissing(true); ``` **解释：**当 过滤条件的列 的 **值为空** 时，不满足条件，即：**不包含该条记录** ### 完整代码 ``` /** * 没有列值，认为不满足查询条件 * @param tableName * @param columnFamily * @param column * @param op * @param value * @return * @throws IOException */ public List<CellData[]> filter(String tableName, String columnFamily, String column, String op, String value) throws IOException { return filter(tableName, columnFamily, column, op, value,true); } ``` ``` /** * * @param tableName 表名 * @param columnFamily 列族名 * @param column 列名 * @param op 操作，=，>，>=，<，<=，!= * @param value 值 * @param filterIfMissing 设置为true，没有列值，认为不满足条件；false，没有列值，也满足条件 * @throws IOException */ public List<CellData[]> filter(String tableName, String columnFamily, String column, String op, String value,boolean filterIfMissing) throws IOException { Table table = conn.getTable(TableName.valueOf(tableName)); //创建Scan Scan scan=new Scan(); SingleColumnValueFilter filter=new SingleColumnValueFilter( Bytes.toBytes(columnFamily), Bytes.toBytes(column), getCompareOperator(op), new BinaryComparator(Bytes.toBytes(value))); // 注意是字符串 filter.setFilterIfMissing(filterIfMissing); //传入filter scan.setFilter(filter); //执行scan ResultScanner resultScanner = table.getScanner(scan); Iterator<Result> iterator = resultScanner.iterator(); List<CellData[]> retList = new ArrayList<>(); //迭代，在迭代时，ResultScanner会发送get请求 while(iterator.hasNext()){ Result result=iterator.next(); //获取rowkey String rowkey=Bytes.toString(result.getRow()); // System.out.print(rowkey+"\t"); //获取所有单元格 List<Cell> list=result.listCells(); CellData[] arr = new CellData[list.size()]; int i = 0; for(Cell item:list){ String family=Bytes.toString(CellUtil.cloneFamily(item)); String qualifier=Bytes.toString(CellUtil.cloneQualifier(item)); String valueDb=Bytes.toString(CellUtil.cloneValue(item)); CellData cellData = new CellData(family,qualifier,rowkey,item.getTimestamp(),valueDb); arr[i] = cellData ; i ++ ; } retList.add(arr); } //用完要及时关闭，在迭代时，ResultScanner会发送get请求 resultScanner.close(); table.close(); return retList; } ``` ``` // 传入 =，>，>=，<，<=，!=，返回相对应的 CompareOperator CompareOperator getCompareOperator(String op){ CompareOperator co = null; switch (op) { case "=": co = CompareOperator.EQUAL; break; case ">": co = CompareOperator.GREATER; break; case ">=": co = CompareOperator.GREATER_OR_EQUAL; break; case "<": co = CompareOperator.LESS; break; case "<=": co = CompareOperator.LESS_OR_EQUAL; break; case "!=": co = CompareOperator.NOT_EQUAL; break; default: co = CompareOperator.NO_OP; } return co; } ``` ### 测试1 ``` public static void main(String[] args) throws IOException { HbaseUtils2_filter_ok utils=new HbaseUtils2_filter_ok(); utils.connect(); // 查询 price 小于等于 099.90的数据 List<CellData[]> resList = utils.filter("book", "c1", "price", "<=", "099.90"); // List<CellData[]> resList = utils.filter("book", "c1", "price", "<=", "099.90",false); for(CellData[] arr : resList){ for(CellData item : arr){ // System.out.println(item.getFamily()+":"+item.getQualifier()+"-"+item.getTimestamp()+" == "+item.getValue()); System.out.print(item.getFamily()+":"+item.getRowkey()+":"+item.getQualifier() +" == "+item.getValue()+"\t\t"); } System.out.println("----------"); } utils.close(); } ``` 正确 原文出处：http://malaoshi.top/show_1IX2JiGBMM4G.html