Java tutorial
package mvm.rya.indexing.accumulo.freetext; /* * 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. */ import java.nio.ByteBuffer; import java.nio.charset.CharacterCodingException; import mvm.rya.indexing.accumulo.StatementSerializer; import org.apache.commons.lang.StringUtils; import org.apache.hadoop.io.Text; import org.openrdf.model.Statement; /** * Row ID: shardId * <p> * CF: CF Prefix + Term */ public class ColumnPrefixes { public static final Text DOCS_CF_PREFIX = new Text("d\0"); public static final Text TERM_CF_PREFIX = new Text("t\0"); public static final Text TERM_LIST_CF_PREFIX = new Text("l\0"); public static final Text REVERSE_TERM_LIST_CF_PREFIX = new Text("r\0"); public static final Text SUBJECT_CF_PREFIX = new Text("s\0"); public static final Text PREDICATE_CF_PREFIX = new Text("p\0"); public static final Text OBJECT_CF_PREFIX = new Text("o\0"); public static final Text CONTEXT_CF_PREFIX = new Text("c\0"); private static Text concat(Text prefix, String str) { Text temp = new Text(prefix); try { ByteBuffer buffer = Text.encode(str, false); temp.append(buffer.array(), 0, buffer.limit()); } catch (CharacterCodingException cce) { throw new IllegalArgumentException(cce); } return temp; } public static Text getTermColFam(String term) { return concat(TERM_CF_PREFIX, term); } public static Text getTermListColFam(String term) { return concat(TERM_LIST_CF_PREFIX, term); } public static Text getRevTermListColFam(String term) { return concat(REVERSE_TERM_LIST_CF_PREFIX, StringUtils.reverse(term)); } public static Text getDocColFam(String term) { return concat(DOCS_CF_PREFIX, term); } public static Text getSubjColFam(String term) { return concat(SUBJECT_CF_PREFIX, term); } public static Text getSubjColFam(Statement statement) { String subj = StatementSerializer.writeSubject(statement); return getSubjColFam(subj); } public static Text getPredColFam(String term) { return concat(PREDICATE_CF_PREFIX, term); } public static Text getPredColFam(Statement statement) { String pred = StatementSerializer.writePredicate(statement); return getPredColFam(pred); } public static Text getObjColFam(String term) { return concat(OBJECT_CF_PREFIX, term); } public static Text getObjColFam(Statement statement) { String obj = StatementSerializer.writeObject(statement); return getObjColFam(obj); } public static Text getContextColFam(String term) { return concat(CONTEXT_CF_PREFIX, term); } public static Text getContextColFam(Statement statement) { String cont = StatementSerializer.writeContext(statement); return getContextColFam(cont); } public static Text removePrefix(Text termWithPrefix) { Text temp = new Text(); temp.set(termWithPrefix.getBytes(), 2, termWithPrefix.getLength() - 2); return temp; } }