/**
* Copyright 2010 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.filter;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
/**
* This comparator is for use with SingleColumnValueFilter, for filtering based on
* the value of a given column. Use it to test if a given substring appears
* in a cell value in the column. The comparison is case insensitive.
* <p>
* Only EQUAL or NOT_EQUAL tests are valid with this comparator.
* <p>
* For example:
* <p>
* <pre>
* SingleColumnValueFilter scvf =
* new SingleColumnValueFilter("col", CompareOp.EQUAL,
* new SubstringComparator("substr"));
* </pre>
*/
public class SubstringComparator extends WritableByteArrayComparable {
private String substr;
/** Nullary constructor for Writable, do not use */
public SubstringComparator() {
super();
}
/**
* Constructor
* @param substr the substring
*/
public SubstringComparator(String substr) {
super(Bytes.toBytes(substr.toLowerCase()));
this.substr = substr.toLowerCase();
}
@Override
public byte[] getValue() {
return Bytes.toBytes(substr);
}
@Override
public int compareTo(byte[] value, int offset, int length) {
return Bytes.toString(value, offset, length).toLowerCase().contains(substr) ? 0
: 1;
}
@Override
public void readFields(DataInput in) throws IOException {
String substr = in.readUTF();
this.value = Bytes.toBytes(substr);
this.substr = substr;
}
@Override
public void write(DataOutput out) throws IOException {
out.writeUTF(substr);
}
}