Thread: Using a CountingBloomFilter (java.lang.VerifyError)

the exception tells you already why your code ran into troubles: Constructor must call super() or this()

the constructor is written by java! I my self did not wrote it to edit.

Is it possible to explain more?

...then pls. post the source so that I can tell you where to look at.
In general: If a java class is an extension of an other Java class the first invocation in its constructor must be super() or super(parameters) or when it calls itself (or recursive) the this() or this(parameters) is used

I found the Counting Bloom Filter from this page:
CountingBloomFilter (Apache Hadoop Main 2.0.0-alpha API)

I think this source code should care about this point.is it?

however now I no more can execute the mentioned code. it seems that java.lang.object does not contain the CountingBloomFilter calss!
I need to have counting bloom filter in my code!

Thanks for your attention.

Silvery,
oh, it's an API. Have you the package org.apache.hadoop.util.bloom. I strongly believe that this API is buggy because your code. Note: The line cbf.add(123) is probably wrong because 2 add methods require an object Key or Filter, not an integer.

add(org.apache.hadoop.util.bloom.Key key)
and(org.apache.hadoop.util.bloom.Filter filter)

CountingBloomFilter cbf=new CountingBloomFilter(12, 4, 1);
cbf.add(123);
System.out.print(cbf);
System.out.print("membership:"+cbf.membershipTest( 1));

is correct. To be sure it's a bug try this:

CountingBloomFilter cbf=new CountingBloomFilter(); // default constructor
System.out.print("cbf="+cbf.toString());

I downloaded the packages and Now the code is as below:

It worked properly:

String s="test";
byte[] nn=new byte[100];
nn=s.getBytes();
System.out.println(nn);
Key mine=new Key(nn);
CountingBloomFilter cbf=new CountingBloomFilter();
cbf.add(mine);
System.out.print(cbf.toString());
System.out.println("\nmembership:"+cbf.membershipT est(mine));

Thank you so much...

Now I created this cbf. I need to save it to a table in mysql and fetch it later.
How can I?
what will be the column's type?
what about the java code to construct the fetched cbf?

Silvery,
glad to hear that it worked. That means either the constructor with parameters is buggy or the misused method add() threw a wrong Exception

Originally Posted by Silvery

Now I created this cbf. I need to save it to a table in mysql and fetch it later.
How can I?
what will be the column's type?
what about the java code to construct the fetched cbf?

Sure you can do that. It depends only on your DB/SQL skill. This API provides 2 methods readFields() and write() for such purpose. You can easily retrieve the data (readFields()) and stow in your SQL table for later use. The question of column type is beyond my knowledge because I can't guess what your data are and what SQL table you want to create. As I said, it depends on your DB/SQL skill.

Hi

After a long Holiday, I came back with this problem!
I really do not know how to save a Counting Bloom Filter in a DB(MY SQL)?I don not know how to use readFileds() would you please help me?

TNX

I solved it, just stored The Bloom Filter in a file and load it from the file