HBase read data returns null

Question

I have created a java application to read data from HBase. I checked link1 link2 link3 and link4. Program returns null even there is data in my table.

hbase shell:

 hbase(main):009:0> get 'login','1'
 COLUMN                CELL                                                      
 password: password   timestamp=1456588594424, value=hpassword                     
 username: username   timestamp=1456588582413, value=husername                     
 2 row(s) in 0.0120 seconds

Code:

Configuration config = HBaseConfiguration.create();
HTable table = new HTable(config, "login");
Get g = new Get(Bytes.toBytes("row1"));
Result r = table.get(g);

byte [] value = r.getValue(Bytes.toBytes("username"),Bytes.toBytes("username"));
byte [] value1 = r.getValue(Bytes.toBytes("password"),Bytes.toBytes("password"));

String valueStr = Bytes.toString(value);
String valueStr1 = Bytes.toString(value1);
System.out.println("username: "+ valueStr+"\npassword: "+valueStr1);
Scan s = new Scan();
s.addColumn(Bytes.toBytes("username"), Bytes.toBytes("username"));
s.addColumn(Bytes.toBytes("password"), Bytes.toBytes("password"));
ResultScanner scanner = table.getScanner(s);

try
{
 for (Result rnext = scanner.next(); rnext != null; rnext = scanner.next())
  {
    System.out.println("Found row : " + rnext);
   }
 }finally{
  scanner.close();
 }

Output:

username: null
password: null

Am I missing something, or do I need to edit somewhere in the code?

Also, I need to implement this into Java Play Framework. Do you have any idea about it?

Thanks in advance.

It's not clear what column family is used for storing data. You use "username" for both column and column family, it seems to e wrong — AdamSkywalker, Feb 28 '16 at 18:50
Thank you for your help. I changed them and also changed Bytes.toBytes("row1")) "row1" to "1". — Alican Balik, Feb 28 '16 at 19:36

score 2 · Answer 1 · answered Feb 29 '16 at 15:20

Try this:

 // Instantiating Configuration class
  Configuration config = HBaseConfiguration.create();

  // Instantiating HTable class
  HTable table = new HTable(config, "tablename");

  // Instantiating the Scan class
  Scan scan = new Scan();

  // Scanning the required columns
  scan.addColumn(Bytes.toBytes("columnfamily"), Bytes.toBytes("column1"));
  scan.addColumn(Bytes.toBytes("columnfamily"), Bytes.toBytes("column2"));

  // Getting the scan result
  ResultScanner scanner = table.getScanner(scan);

  // Reading values from scan result
  for (Result result = scanner.next(); result != null; result = scanner.next())

  System.out.println("Found row : " + result);
  //closing the scanner
  scanner.close();

Column name and column family had the same name and I changed their names. It is working perfectly now. Thank you for cleaner code. — Alican Balik, Mar 01 '16 at 13:59

score 2 · Accepted Answer · answered Mar 01 '16 at 14:00

2

as @AdamSkywalker said that I needed to change names of column name and column family. I was getting null return when their names were same. I renamed them and code works perfectly.

answered Mar 01 '16 at 14:00

Alican Balik

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HBase read data returns null

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