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Posted to commits@hbase.apache.org by st...@apache.org on 2008/11/21 22:17:24 UTC
svn commit: r719717 - in /hadoop/hbase/trunk: CHANGES.txt
src/java/org/apache/hadoop/hbase/client/tableindexed/IndexSpecification.java
src/java/org/apache/hadoop/hbase/client/tableindexed/IndexedTable.java
src/java/overview.html
Author: stack
Date: Fri Nov 21 13:17:24 2008
New Revision: 719717
URL: http://svn.apache.org/viewvc?rev=719717&view=rev
Log:
HBASE-1016 Fix example in javadoc overview
Modified:
hadoop/hbase/trunk/CHANGES.txt
hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexSpecification.java
hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexedTable.java
hadoop/hbase/trunk/src/java/overview.html
Modified: hadoop/hbase/trunk/CHANGES.txt
URL: http://svn.apache.org/viewvc/hadoop/hbase/trunk/CHANGES.txt?rev=719717&r1=719716&r2=719717&view=diff
==============================================================================
--- hadoop/hbase/trunk/CHANGES.txt (original)
+++ hadoop/hbase/trunk/CHANGES.txt Fri Nov 21 13:17:24 2008
@@ -80,6 +80,7 @@
HBASE-910 Scanner misses columns / rows when the scanner is obtained
durring a memcache flush
HBASE-1009 Master stuck in loop wanting to assign but regions are closing
+ HBASE-1016 Fix example in javadoc overvie
IMPROVEMENTS
HBASE-901 Add a limit to key length, check key and value length on client side
Modified: hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexSpecification.java
URL: http://svn.apache.org/viewvc/hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexSpecification.java?rev=719717&r1=719716&r2=719717&view=diff
==============================================================================
--- hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexSpecification.java (original)
+++ hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexSpecification.java Fri Nov 21 13:17:24 2008
@@ -59,7 +59,6 @@
* @param indexedColumns
* @param additionalColumns
* @param keyGenerator
- * @param keyComparator
*/
public IndexSpecification(String indexId, byte[][] indexedColumns,
byte[][] additionalColumns, IndexKeyGenerator keyGenerator) {
Modified: hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexedTable.java
URL: http://svn.apache.org/viewvc/hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexedTable.java?rev=719717&r1=719716&r2=719717&view=diff
==============================================================================
--- hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexedTable.java (original)
+++ hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/client/tableindexed/IndexedTable.java Fri Nov 21 13:17:24 2008
@@ -52,7 +52,6 @@
private Map<String, HTable> indexIdToTable = new HashMap<String, HTable>();
- /** {@inheritDoc} */
public IndexedTable(final HBaseConfiguration conf, final byte[] tableName)
throws IOException {
super(conf, tableName);
Modified: hadoop/hbase/trunk/src/java/overview.html
URL: http://svn.apache.org/viewvc/hadoop/hbase/trunk/src/java/overview.html?rev=719717&r1=719716&r2=719717&view=diff
==============================================================================
--- hadoop/hbase/trunk/src/java/overview.html (original)
+++ hadoop/hbase/trunk/src/java/overview.html Fri Nov 21 13:17:24 2008
@@ -195,6 +195,7 @@
import org.apache.hadoop.hbase.io.BatchUpdate;
import org.apache.hadoop.hbase.io.Cell;
import org.apache.hadoop.hbase.io.RowResult;
+import org.apache.hadoop.hbase.util.Bytes;
public class MyClient {
@@ -209,17 +210,20 @@
// To do any sort of update on a row, you use an instance of the BatchUpdate
// class. A BatchUpdate takes a row and optionally a timestamp which your
- // updates will affect.
+ // updates will affect. If no timestamp, the server applies current time
+ // to the edits.
BatchUpdate batchUpdate = new BatchUpdate("myRow");
- // The BatchUpdate#put method takes a Text that describes what cell you want
- // to put a value into, and a byte array that is the value you want to
- // store. Note that if you want to store strings, you have to getBytes()
- // from the string for HBase to understand how to store it. (The same goes
- // for primitives like ints and longs and user-defined classes - you must
- // find a way to reduce it to bytes.)
+ // The BatchUpdate#put method takes a byte [] (or String) that designates
+ // what cell you want to put a value into, and a byte array that is the
+ // value you want to store. Note that if you want to store Strings, you
+ // have to getBytes() from the String for HBase to store it since HBase is
+ // all about byte arrays. The same goes for primitives like ints and longs
+ // and user-defined classes - you must find a way to reduce it to bytes.
+ // The Bytes class from the hbase util package has utility for going from
+ // String to utf-8 bytes and back again and help for other base types.
batchUpdate.put("myColumnFamily:columnQualifier1",
- "columnQualifier1 value!".getBytes());
+ Bytes.toBytes("columnQualifier1 value!"));
// Deletes are batch operations in HBase as well.
batchUpdate.delete("myColumnFamily:cellIWantDeleted");
@@ -235,7 +239,9 @@
// value contained is a string and want an actual string, then you must
// convert it yourself.
Cell cell = table.get("myRow", "myColumnFamily:columnQualifier1");
- String valueStr = new String(cell.getValue());
+ // This could throw a NullPointerException if there was no value at the cell
+ // location.
+ String valueStr = Bytes.toString(cell.getValue());
// Sometimes, you won't know the row you're looking for. In this case, you
// use a Scanner. This will give you cursor-like interface to the contents
@@ -245,30 +251,31 @@
table.getScanner(new String[]{"myColumnFamily:columnQualifier1"});
- // Scanners in HBase 0.2 return RowResult instances. A RowResult is like the
- // row key and the columns all wrapped up in a single interface.
+ // Scanners return RowResult instances. A RowResult is like the
+ // row key and the columns all wrapped up in a single Object.
// RowResult#getRow gives you the row key. RowResult also implements
// Map, so you can get to your column results easily.
// Now, for the actual iteration. One way is to use a while loop like so:
RowResult rowResult = scanner.next();
- while(rowResult != null) {
+ while (rowResult != null) {
// print out the row we found and the columns we were looking for
- System.out.println("Found row: " + new String(rowResult.getRow()) + " with value: " +
- rowResult.get("myColumnFamily:columnQualifier1".getBytes()));
-
+ System.out.println("Found row: " + Bytes.toString(rowResult.getRow()) +
+ " with value: " + rowResult.get(Bytes.toBytes("myColumnFamily:columnQualifier1")));
rowResult = scanner.next();
}
// The other approach is to use a foreach loop. Scanners are iterable!
for (RowResult result : scanner) {
// print out the row we found and the columns we were looking for
- System.out.println("Found row: " + new String(result.getRow()) + " with value: " +
- result.get("myColumnFamily:columnQualifier1".getBytes()));
+ System.out.println("Found row: " + Bytes.toString(rowResult.getRow()) +
+ " with value: " + rowResult.get(Bytes.toBytes("myColumnFamily:columnQualifier1")));
}
// Make sure you close your scanners when you are done!
+ // Its probably best to put the iteration into a try/finally with the below
+ // inside the finally clause.
scanner.close();
}
}