HBase0.89常用API接口使用

HTable：这个是table对象，通过他来完成对hbase表的各种操作，删除，更新，创建，查询

RowFilter：对rowkey过滤查询的类

QualifierFilter：对子列做过滤查询的类

FilterList：复合filter的实现类

Get：rowkey定位器

Scan：查询扫描器

ResultScanner：查询结果扫描器

Result：单个查询结果

KeyValue：查询结果中的keyvalue原子项

//场景一，通过rowkey，列族，子列直接定位value

Configuration conf = Configuration.create(); HTable table = new HTable(conf,”mytable”); Get get = new Get(“rowkey1”.getBytes()); get.addFamily(“myfamily”.getBytes()); Result rs = table.get(get); If(rs.isEmpty()){ System.out.println(“no record”); }else{ List<KeyValue> kvList = rs.list(); for(KeyValue kv : kvList){ System.out.println(new String(kv.getRow(),”UTF-8”) + “->”); System.out.println(new String(kv.getQualifier (),”UTF-8”) + “:”); System.out.println(new String(kv.getValue(),”UTF-8”) ); } }

//场景二，使用rowkey的模糊匹配来查询

Configuration conf = Configuration.create(); HTable table = new HTable(conf,”mytable”); Scan sc = new Scan(“somewords”) sc.addFamily(“myfamily”.getBytes()); ResultScanner rsan = table.getScanner(sc); Resullt rs = rsan.next(); If(rs==null){ System.out.println(“no record”); }else{ While(rs!=null){ List<KeyValue> kvList = rs.list(); for(KeyValue kv : kvList){ System.out.println(new String(kv.getRow(),”UTF-8”) + “->”); System.out.println(new String(kv.getQualifier (),”UTF-8”) + “:”); System.out.println(new String(kv.getValue(),”UTF-8”) ); } rs = rsan.next(); } }

//场景三，使用rowkey和子列的filter进行条件查询

Configuration conf = Configuration.create(); HTable table = new HTable(conf,”mytable”); Scan sc = new Scan() sc.addFamily(“myfamily”.getBytes()); RowFilter filter1 = new RowFilter(CompareOp.EQUAL, new RegexStringComparator(“^”+accountlike+”~(.*)”));//利用正则表达式来查找rowkey QualifierFilter filter2 = new QualifierFilter(CompareOp.LESS_OR_EQUAL,new BinaryComparator(“stop”.getBytes())); QualifierFilter filter3 = new QualifierFilter(CompareOp.GREATER_OR_EQUAL,new BinaryComparator(“start”.getBytes())); FilterList flist = new FilterList(FilterList.Operator.MUST_PASS_ALL); flist.addFilter(filter1); flist.addFilter(filter2); flist.addFilter(filter3); sc.addFilter(flist); ResultScanner rsan = table.getScanner(sc); Resullt rs = rsan.next(); If(rs==null){ System.out.println(“no record”); }else{ While(rs!=null){ List<KeyValue> kvList = rs.list(); for(KeyValue kv : kvList){ System.out.println(new String(kv.getRow(),”UTF-8”) + “->”); System.out.println(new String(kv.getQualifier (),”UTF-8”) + “:”); System.out.println(new String(kv.getValue(),”UTF-8”) ); } rs = rsan.next(); } }

未完待续。。。