Changes between Initial Version and Version 1 of waue/2011/0426_4_4

Timestamp:

Apr 25, 2011, 3:55:10 PM (13 years ago)

Author:

waue

Comment:

--

waue/2011/0426_4_4

@@ +1 @@
+{{{
+#!html
+<div style="text-align: center; color:#151B8D"><big style="font-weight: bold;"><big><big>
+ITRI HBase 進階課程 
+</big></big></big></div> <div style="text-align: center; color:#7E2217"><big style="font-weight: bold;"><big>
+HBase 範例
+</big></big></div>
+}}}
+
+[wiki:waue/2011/0426_4_3 上一關 < ] 第四關 [wiki:waue/2011/0426_4_5 > 下一關]
+
+ = 範例四： 掃描並印出指定的column-Qualifier 的所有列值 = 
+
+{{{
+#!java
+
+package itri;
+
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.client.HTable;
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.client.ResultScanner;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.util.GenericOptionsParser;
+
+public class ScanTableV1 {
+
+        static void ScanColumn(String tablename, String family, String column) {
+                HBaseConfiguration conf = new HBaseConfiguration();
+
+                HTable table;
+                try {
+                        table = new HTable(conf, Bytes.toBytes(tablename));
+
+                        ResultScanner scanner = table.getScanner(Bytes.toBytes(family));
+
+                        System.out.println("Scan the Table [" + tablename
+                                        + "]'s Column => " + family + ":" + column);
+                        int i = 1;
+                        for (Result rowResult : scanner) {
+                                byte[] by = rowResult.getValue(Bytes.toBytes(family), Bytes
+                                                .toBytes(column));
+                                String str = Bytes.toString(by);
+                                System.out.println("row " + i + " is \"" + str + "\"");
+                                i++;
+                        }
+                } catch (IOException e) {
+                        e.printStackTrace();
+                }
+        }
+
+        public static void main(String[] argv) {
+//              String[] argc = {"t1", "f1", "c1"};argv = argc;
+                
+                String[] args = new GenericOptionsParser(new Configuration(), argv)
+                                .getRemainingArgs();
+                if (args.length < 3) {
+                        System.out
+                                        .println("ScanTableV1 <TableName> <Family> <Qualifier> ");
+                        return;
+                }
+                ScanColumn(args[0], args[1], args[2]);
+        }
+}
+}}}
+
+ * 執行結果
+
+{{{
+Scan the Table [ex1Table]'s Column => Detail:c1
+row 1 is "my value good"
+}}}
+
+{{{
+$ bin/hadoop jar ItriMenu.jar PutData "ex1Table" "row222" "Detail" "c1" "my value better"
+$ bin/hadoop jar ItriMenu.jar ScanTable "ex1Table" "Detail" "c1"
+row 1 is "my value good"
+row 2 is "my value better"
+
+}}}
+
+
+ = 進階： 給 table name 即可掃出全部值 = 
+
+{{{
+#!java
+package itri;
+
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.client.Get;
+import org.apache.hadoop.hbase.client.HTable;
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.client.ResultScanner;
+import org.apache.hadoop.hbase.client.Scan;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.util.GenericOptionsParser;
+
+public class ScanTableV2 {
+
+        static void ScanColumn(String tablename) throws IOException {
+                HBaseConfiguration conf = new HBaseConfiguration();
+
+                HTable table = new HTable(conf, Bytes.toBytes(tablename));
+                Scan s = new Scan();
+                ResultScanner scanner = table.getScanner(s);
+                try {
+
+                        for (Result rr : scanner) {
+
+                                byte[] row_b = rr.getRow();
+                                String row_s = Bytes.toString(row_b);
+                                System.out.print("row= " +row_s );
+                                for (KeyValue kv : rr.list()) {
+
+                                        byte[] family_b = kv.getFamily();
+                                        String family_s = Bytes.toString(family_b);
+
+                                        byte[] qfy_b = kv.getQualifier();
+                                        String qfy_s = Bytes.toString(qfy_b);
+
+                                        Get g = new Get(row_b);
+                                        Result rowResult = table.get(g);
+                                        
+                                        String val = Bytes.toString(rowResult.getValue(family_b,
+                                                        qfy_b));
+                                        System.out.print(" {"+family_s +":"+qfy_s +" = "+val +"}");
+                                }
+                                System.out.println(" ");
+                        }
+
+                } finally {
+                        scanner.close();
+                }
+        }
+
+        public static void main(String[] argv) throws IOException {
+//              String[] argc = {"t1"};argv = argc;
+
+                String[] args = new GenericOptionsParser(new Configuration(), argv)
+                                .getRemainingArgs();
+                if (args.length < 1) {
+                        System.out.println("ScanTableV2 <TableName> ");
+                        return;
+                }
+                ScanColumn(args[0]);
+        }
+}
+}}}