每日日报2021 10/18
没有想到，这么一个小小的项目写这么久。今天写插入数据等操作。
public static void addRowData(String tableName, String rowKey,
String columnFamily, String
column, String value) throws IOException{
//创建 HTable 对象
HTable hTable = new HTable(conf, tableName);
//向表中插入数据
Put put = new Put(Bytes.toBytes(rowKey));
//向 Put 对象中组装数据
put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(column),
Bytes.toBytes(value));
hTable.put(put);
hTable.close();
System.out.println("插入数据成功");
}
4.2.6 删除多行数据
public static void deleteMultiRow(String tableName, String... rows)
throws IOException{
HTable hTable = new HTable(conf, tableName);
List<Delete> deleteList = new ArrayList<Delete>();
for(String row : rows){
Delete delete = new Delete(Bytes.toBytes(row));
deleteList.add(delete);
}
hTable.delete(deleteList);
hTable.close();
}
4.2.7 获取所有数据
public static void getAllRows(String tableName) throws IOException{
HTable hTable = new HTable(conf, tableName);
//得到用于扫描 region 的对象
Scan scan = new Scan();
//使用 HTable 得到 resultcanner 实现类的对象
ResultScanner resultScanner = hTable.getScanner(scan);
for(Result result : resultScanner){
Cell[] cells = result.rawCells();
for(Cell cell : cells){
//得到 rowkey
System.out.println("
行 键
:"
+
Bytes.toString(CellUtil.cloneRow(cell)));
//得到列族
System.out.println("
列 族
" +
Bytes.toString(CellUtil.cloneFamily(cell)));
System.out.println("
列
:" +
Bytes.toString(CellUtil.cloneQualifier(cell)));
System.out.println("
值
:" +
Bytes.toString(CellUtil.cloneValue(cell)));
}
}
}
4.2.8 获取某一行数据
public static void getRow(String tableName, String rowKey) throws
IOException{
HTable table = new HTable(conf, tableName);
Get get = new Get(Bytes.toBytes(rowKey));
//get.setMaxVersions();显示所有版本
//get.setTimeStamp();显示指定时间戳的版本
Result result = table.get(get);
for(Cell cell : result.rawCells()){
System.out.println("
行 键
:" +
Bytes.toString(result.getRow()));
System.out.println("
列 族
" +
Bytes.toString(CellUtil.cloneFamily(cell)));
System.out.println("
列
:" +
Bytes.toString(CellUtil.cloneQualifier(cell)));
System.out.println("
值
:" +
Bytes.toString(CellUtil.cloneValue(cell)));
System.out.println("时间戳:" + cell.getTimestamp());
}
}
4.2.9 获取某一行指定“列族:列”的数据
public static void getRowQualifier(String tableName, String rowKey,
String family, String
qualifier) throws IOException{
HTable table = new HTable(conf, tableName);
Get get = new Get(Bytes.toBytes(rowKey));
get.addColumn(Bytes.toBytes(family),
Bytes.toBytes(qualifier));
Result result = table.get(get);
for(Cell cell : result.rawCells()){
System.out.println("
行 键
:" +
Bytes.toString(result.getRow()));
System.out.println("
列 族
" +
Bytes.toString(CellUtil.cloneFamily(cell)));
System.out.println("
列
:" +
Bytes.toString(CellUtil.cloneQualifier(cell)));
System.out.println("
值
:" +
Bytes.toString(CellUtil.cloneValue(cell)));
}
}
