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hbase开发实例
1、put/checkAndPut
1 package com.testdata; 2 3 import java.io.IOException; 4 import org.apache.hadoop.conf.Configuration; 5 import org.apache.hadoop.hbase.HBaseConfiguration; 6 import org.apache.hadoop.hbase.client.HConnection; 7 import org.apache.hadoop.hbase.client.HConnectionManager; 8 import org.apache.hadoop.hbase.client.HTableInterface; 9 import org.apache.hadoop.hbase.client.Put; 10 import org.apache.hadoop.hbase.util.Bytes; 11 12 public class TestPut { 13 14 public static void main(String[] args) throws IOException { 15 16 Configuration conf = HBaseConfiguration.create(); 17 conf.set("hbase.zookeeper.quorum","localhost"); 18 conf.set("hbase.zookeeper.property.clientPort","2181"); 19 HConnection conn = HConnectionManager.createConnection(conf); 20 21 HTableInterface table = conn.getTable("testdata"); 22 Put testput = new Put(Bytes.toBytes("row1")); 23 testput.add(Bytes.toBytes("cf"),Bytes.toBytes("col1"),Bytes.toBytes("E")); 24 table.put(testput); 25 //使用checkAndPut 26 table.checkAndPut(Bytes.toBytes("row1"), Bytes.toBytes("cf"),Bytes.toBytes("col5"),Bytes.toBytes("E"),testput); 27 table.close(); 28 conn.close(); 29 30 } 31 32 }
使用checkAndPut，需要先对数据进行验证，上面的例子中，向row1中的cf:col1写入数据"E"，而验证的是row1中的cf:col5的值是否为"E"，注意这一点，相当于加了条件。
2、使用get读取数据
1 package com.testdata; 2 3 import java.io.IOException; 4 import java.util.List; 5 6 import org.apache.hadoop.conf.Configuration; 7 import org.apache.hadoop.hbase.Cell; 8 import org.apache.hadoop.hbase.CellUtil; 9 import org.apache.hadoop.hbase.HBaseConfiguration; 10 import org.apache.hadoop.hbase.client.Get; 11 import org.apache.hadoop.hbase.client.HConnection; 12 import org.apache.hadoop.hbase.client.HConnectionManager; 13 import org.apache.hadoop.hbase.client.HTableInterface; 14 import org.apache.hadoop.hbase.client.Result; 15 16 17 import org.apache.hadoop.hbase.util.Bytes; 18 19 public class TestGet { 20 21 public static void main(String[] args) throws IOException { 22 Configuration conf = HBaseConfiguration.create(); 23 conf.set("hbase.zookeeper.quorum","localhost"); 24 conf.set("hbase.zookeeper.property.clientPort","2181"); 25 HConnection conn = HConnectionManager.createConnection(conf); 26 HTableInterface table = conn.getTable("testdata"); 27 28 Get testget = new Get(Bytes.toBytes("row1")); 29 Result row1 = table.get(testget); 30 String value = http://www.mamicode.com/new String(row1.getValue(Bytes.toBytes("cf"), Bytes.toBytes("col1"))); 31 System.out.println(value); 32 //下面限定到具体的列 33 testget.addColumn(Bytes.toBytes("cf"), Bytes.toBytes("col2")); 34 Result result = table.get(testget); 35 if(result.getValue(Bytes.toBytes("cf"), Bytes.toBytes("col2")) != null){ 36 String value2 = new String(result.getValue(Bytes.toBytes("cf"), Bytes.toBytes("col2"))); 37 System.out.println(value2); 38 } 39 //另外一种读取方式 40 List<Cell> cells = row1.listCells(); 41 for(Cell cell : cells){ 42 String rowkey = new String(CellUtil.cloneRow(cell)); 43 String family = new String(CellUtil.cloneFamily(cell)); 44 String collumn = new String(CellUtil.cloneQualifier(cell)); 45 String cvalue = http://www.mamicode.com/new String(CellUtil.cloneValue(cell)); 46 System.out.println("rowkey:" + rowkey + " family:" + family + " column:" + collumn +" value:" + cvalue); 47 48 } 49 50 //注意要关闭 51 table.close(); 52 conn.close(); 53 54 } 55 56 }
参考结果：
3、使用scan获取数据
1 package com.testdata; 2 3 import java.io.IOException; 4 import java.util.List; 5 import org.apache.hadoop.conf.Configuration; 6 import org.apache.hadoop.hbase.Cell; 7 import org.apache.hadoop.hbase.CellUtil; 8 import org.apache.hadoop.hbase.HBaseConfiguration; 9 import org.apache.hadoop.hbase.client.HConnection; 10 import org.apache.hadoop.hbase.client.HConnectionManager; 11 import org.apache.hadoop.hbase.client.HTableInterface; 12 import org.apache.hadoop.hbase.client.Result; 13 import org.apache.hadoop.hbase.client.ResultScanner; 14 import org.apache.hadoop.hbase.client.Scan; 15 16 public class TestScan { 17 18 public static void main(String[] args) throws IOException { 19 Configuration conf = HBaseConfiguration.create(); 20 conf.set("hbase.zookeeper.quorum","localhost"); 21 conf.set("hbase.zookeeper.property.clientPort","2181"); 22 HConnection conn = HConnectionManager.createConnection(conf); 23 HTableInterface table = conn.getTable("testdata"); 24 25 Scan testscan =new Scan(); 26 ResultScanner rs = table.getScanner(testscan); 27 for(Result r : rs ){ 28 List<Cell> cells = r.listCells(); 29 for(Cell cell : cells){ 30 String rowkey = new String(CellUtil.cloneRow(cell)); 31 String family = new String(CellUtil.cloneFamily(cell)); 32 String collumn = new String(CellUtil.cloneQualifier(cell)); 33 String cvalue = http://www.mamicode.com/new String(CellUtil.cloneValue(cell)); 34 System.out.println("rowkey:" + rowkey + " family:" + family + " column:" + collumn +" value:" + cvalue); 35 36 } 37 } 38 rs.close(); 39 table.close(); 40 conn.close(); 41 42 } 43 44 }
4、delete/checkAndDelete
1 package com.testdata; 2 3 import org.apache.hadoop.conf.Configuration; 4 import org.apache.hadoop.hbase.HBaseConfiguration; 5 import org.apache.hadoop.hbase.client.Delete; 6 import org.apache.hadoop.hbase.client.HConnection; 7 import org.apache.hadoop.hbase.client.HConnectionManager; 8 import org.apache.hadoop.hbase.client.HTableInterface; 9 import java.io.IOException; 10 11 import org.apache.hadoop.hbase.util.Bytes; 12 13 public class TestDelete { 14 15 public static void main(String[] args) throws IOException { 16 Configuration conf = HBaseConfiguration.create(); 17 conf.set("hbase.zookeeper.quorum","localhost"); 18 conf.set("hbase.zookeeper.property.clientPort","2181"); 19 HConnection conn = HConnectionManager.createConnection(conf); 20 HTableInterface table = conn.getTable("testdata"); 21 22 Delete testdelete = new Delete(Bytes.toBytes("row1")); 23 testdelete.deleteColumns(Bytes.toBytes("cf"), Bytes.toBytes("col1")); 24 //区别只是checkAndDelete需要进行验证，相当于加了前提条件 25 //table.delete(testdelete); 26 table.checkAndDelete(Bytes.toBytes("row1"), Bytes.toBytes("cf"), Bytes.toBytes("col2"),Bytes.toBytes("BC"), testdelete); 27 table.close(); 28 conn.close(); 29 30 } 31 32 }
5、append
1 package com.testdata; 2 3 import java.io.IOException; 4 import org.apache.hadoop.conf.Configuration; 5 import org.apache.hadoop.hbase.HBaseConfiguration; 6 import org.apache.hadoop.hbase.client.Append; 7 import org.apache.hadoop.hbase.client.HConnection; 8 import org.apache.hadoop.hbase.client.HConnectionManager; 9 import org.apache.hadoop.hbase.client.HTableInterface; 10 import org.apache.hadoop.hbase.util.Bytes; 11 12 public class TestAppend { 13 14 public static void main(String[] args) throws IOException { 15 Configuration conf = HBaseConfiguration.create(); 16 conf.set("hbase.zookeeper.quorum","localhost"); 17 conf.set("hbase.zookeeper.property.clientPort","2181"); 18 HConnection conn = HConnectionManager.createConnection(conf); 19 HTableInterface table = conn.getTable("testdata"); 20 21 Append testappend = new Append(Bytes.toBytes("row1")); 22 testappend.add(Bytes.toBytes("cf"),Bytes.toBytes("col1"),Bytes.toBytes("F")); 23 table.append(testappend); 24 table.close(); 25 conn.close(); 26 } 27 28 }
下面是结果，注意append是在原有的值之上附加，先前的值为"E"，现在变为"EF"
6、计数器
计数器可以用于统计用户数，点击量等信息
1 package com.testdata; 2 3 import java.io.IOException; 4 import org.apache.hadoop.conf.Configuration; 5 import org.apache.hadoop.hbase.HBaseConfiguration; 6 import org.apache.hadoop.hbase.client.HConnection; 7 import org.apache.hadoop.hbase.client.HConnectionManager; 8 import org.apache.hadoop.hbase.client.HTableInterface; 9 import org.apache.hadoop.hbase.util.Bytes; 10 11 public class TestIncrement { 12 13 public static void main(String[] args) throws IOException { 14 Configuration conf = HBaseConfiguration.create(); 15 conf.set("hbase.zookeeper.quorum","localhost"); 16 conf.set("hbase.zookeeper.property.clientPort","2181"); 17 HConnection conn = HConnectionManager.createConnection(conf); 18 HTableInterface table = conn.getTable("testdata"); 19 20 long result = table.incrementColumnValue(Bytes.toBytes("row1"),Bytes.toBytes("cf"),Bytes.toBytes("coli"), 10); 21 22 System.out.println(result); 23 table.close(); 24 conn.close(); 25 26 } 27 28 }
注意 long result = table.incrementColumnValue(Bytes.toBytes("row1"),Bytes.toBytes("cf"),Bytes.toBytes("coli"), 10);
最后一个参数，可以为0，意味着读取，也可以是负数。
可以使用get_counter可以获取对应的计数器的值，也可以使用以下命令进行操作
incr ‘<table>‘, ‘<row>‘, ‘<column>‘, |<increment-value>|
7、filter
使用时注意性能
1 package com.testdata; 2 3 import java.io.IOException; 4 import java.util.List; 5 import org.apache.hadoop.conf.Configuration; 6 import org.apache.hadoop.hbase.Cell; 7 import org.apache.hadoop.hbase.CellUtil; 8 import org.apache.hadoop.hbase.HBaseConfiguration; 9 import org.apache.hadoop.hbase.client.HConnection; 10 import org.apache.hadoop.hbase.client.HConnectionManager; 11 import org.apache.hadoop.hbase.client.HTableInterface; 12 import org.apache.hadoop.hbase.client.Result; 13 import org.apache.hadoop.hbase.client.ResultScanner; 14 import org.apache.hadoop.hbase.client.Scan; 15 import org.apache.hadoop.hbase.filter.BinaryComparator; 16 import org.apache.hadoop.hbase.filter.BinaryPrefixComparator; 17 import org.apache.hadoop.hbase.filter.CompareFilter; 18 import org.apache.hadoop.hbase.filter.Filter; 19 import org.apache.hadoop.hbase.filter.QualifierFilter; 20 import org.apache.hadoop.hbase.filter.RowFilter; 21 import org.apache.hadoop.hbase.filter.SubstringComparator; 22 import org.apache.hadoop.hbase.util.Bytes; 23 24 public class TestSimplefilter { 25 26 public static void main(String[] args) throws IOException { 27 Configuration conf = HBaseConfiguration.create(); 28 conf.set("hbase.zookeeper.quorum","localhost"); 29 conf.set("hbase.zookeeper.property.clientPort","2181"); 30 HConnection conn = HConnectionManager.createConnection(conf); 31 HTableInterface table = conn.getTable("testdata"); 32 33 Scan sc = new Scan(); 34 sc.setCacheBlocks(false); 35 //行过滤器，判断"row1"与行的key是否相等 36 //Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new BinaryComparator(Bytes.toBytes("row1"))); 37 //是否以"row"为前缀 38 //Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new BinaryPrefixComparator(Bytes.toBytes("row"))); 39 //是否包含"row" 40 //Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL,new SubstringComparator("row")); 41 42 //列过滤器，与行类似 43 Filter filter = new QualifierFilter(CompareFilter.CompareOp.EQUAL,new BinaryComparator(Bytes.toBytes("col1"))); 44 45 sc.setFilter(filter); 46 47 ResultScanner rs = table.getScanner(sc); 48 for(Result r : rs ){ 49 List<Cell> cells = r.listCells(); 50 for(Cell cell : cells){ 51 String rowkey = new String(CellUtil.cloneRow(cell)); 52 String family = new String(CellUtil.cloneFamily(cell)); 53 String collumn = new String(CellUtil.cloneQualifier(cell)); 54 String cvalue = http://www.mamicode.com/new String(CellUtil.cloneValue(cell)); 55 System.out.println("rowkey:" + rowkey + " family:" + family + " column:" + collumn +" value:" + cvalue); 56 } 57 } 58 rs.close(); 59 table.close(); 60 conn.close(); 61 } 62 }
使用filterlist
1 package com.testdata; 2 3 import java.io.IOException; 4 import java.util.ArrayList; 5 import java.util.List; 6 import org.apache.hadoop.conf.Configuration; 7 import org.apache.hadoop.hbase.Cell; 8 import org.apache.hadoop.hbase.CellUtil; 9 import org.apache.hadoop.hbase.HBaseConfiguration; 10 import org.apache.hadoop.hbase.client.HConnection; 11 import org.apache.hadoop.hbase.client.HConnectionManager; 12 import org.apache.hadoop.hbase.client.HTableInterface; 13 import org.apache.hadoop.hbase.client.Result; 14 import org.apache.hadoop.hbase.client.ResultScanner; 15 import org.apache.hadoop.hbase.client.Scan; 16 import org.apache.hadoop.hbase.filter.BinaryComparator; 17 import org.apache.hadoop.hbase.filter.BinaryPrefixComparator; 18 import org.apache.hadoop.hbase.filter.CompareFilter; 19 import org.apache.hadoop.hbase.filter.Filter; 20 import org.apache.hadoop.hbase.filter.FilterList; 21 import org.apache.hadoop.hbase.filter.QualifierFilter; 22 import org.apache.hadoop.hbase.filter.RegexStringComparator; 23 import org.apache.hadoop.hbase.filter.RowFilter; 24 import org.apache.hadoop.hbase.filter.SingleColumnValueFilter; 25 import org.apache.hadoop.hbase.filter.SubstringComparator; 26 import org.apache.hadoop.hbase.util.Bytes; 27 28 public class TestFilterList { 29 30 public static void main(String[] args) throws IOException { 31 Configuration conf = HBaseConfiguration.create(); 32 conf.set("hbase.zookeeper.quorum","localhost"); 33 conf.set("hbase.zookeeper.property.clientPort","2181"); 34 HConnection conn = HConnectionManager.createConnection(conf); 35 HTableInterface table = conn.getTable("testdata"); 36 37 Scan sc = new Scan(); 38 Filter filter1 = new RowFilter(CompareFilter.CompareOp.EQUAL,new BinaryComparator(Bytes.toBytes("row2"))); 39 SingleColumnValueFilter filter2 = new SingleColumnValueFilter(Bytes.toBytes("cf"),Bytes.toBytes("col1"),CompareFilter.CompareOp.EQUAL,new BinaryPrefixComparator(Bytes.toBytes("B"))); 40 41 SingleColumnValueFilter filter3 = new SingleColumnValueFilter(Bytes.toBytes("cf"),Bytes.toBytes("col1"),CompareFilter.CompareOp.EQUAL,new RegexStringComparator("B|C")); 42 filter2.setFilterIfMissing(true); 43 filter3.setFilterIfMissing(true); 44 45 //List<Filter> filters = new ArrayList<Filter>(); 46 //filters.add(filter1); 47 //filters.add(filter2); 48 //FilterList filterlist = new FilterList(filters); 49 50 //也可以这样写,MUST_PASS_ALL标识满足所有的filter,当然也可以使用MUST_PASS_ONE，标识只需要满足一个 51 FilterList filterlist = new FilterList(FilterList.Operator.MUST_PASS_ALL); 52 filterlist.addFilter(filter1); 53 filterlist.addFilter(filter2); 54 filterlist.addFilter(filter3); 55 sc.addColumn(Bytes.toBytes("cf"),Bytes.toBytes("col1")); 56 sc.setFilter(filterlist); 57 58 ResultScanner rs = table.getScanner(sc); 59 for(Result r : rs ){ 60 List<Cell> cells = r.listCells(); 61 for(Cell cell : cells){ 62 String rowkey = new String(CellUtil.cloneRow(cell)); 63 String family = new String(CellUtil.cloneFamily(cell)); 64 String collumn = new String(CellUtil.cloneQualifier(cell)); 65 String cvalue = http://www.mamicode.com/new String(CellUtil.cloneValue(cell)); 66 System.out.println("rowkey:" + rowkey + " family:" + family + " column:" + collumn +" value:" + cvalue); 67 } 68 } 69 rs.close(); 70 table.close(); 71 conn.close(); 72 } 73 }
以上一组filter标识了这样的条件，即行的key必须为"row2"，列名必须为"col1"，值必须为"B"
结果参考：
如果没有 sc.addColumn(Bytes.toBytes("cf"),Bytes.toBytes("col1"));这一句，结果会是下面的样子
rowkey:row2 family:cf column:col1 value:B rowkey:row2 family:cf column:colb value:U
问题出在 SingleColumnValueFilter filter2 = new SingleColumnValueFilter(Bytes.toBytes("cf"),Bytes.toBytes("col1"),CompareFilter.CompareOp.EQUAL,new BinaryPrefixComparator(Bytes.toBytes("B")));这一句，如果打印Bytes.toBytes("B")与Bytes.toBytes("U")，会发现都是以"B"开头的。即使换成BinaryComparator，也不会解决问题。
这里是值得注意的地方，搜索网络可以发现一样的结论，使用时务必使用sc.addColumn(Bytes.toBytes("cf"),Bytes.toBytes("col1"))类似的语句。
rowkey:row2 family:cf column:col1 value:B
hbase开发实例
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