Java tutorial
/* * 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.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators; import java.util.HashMap; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.pig.PigException; import org.apache.pig.backend.executionengine.ExecException; import org.apache.pig.backend.hadoop.executionengine.physicalLayer.POStatus; import org.apache.pig.backend.hadoop.executionengine.physicalLayer.Result; import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhyPlanVisitor; import org.apache.pig.data.DataType; import org.apache.pig.impl.plan.NodeIdGenerator; import org.apache.pig.impl.plan.OperatorKey; import org.apache.pig.impl.plan.VisitorException; public class NotEqualToExpr extends BinaryComparisonOperator { /** * */ private static final long serialVersionUID = 1L; transient private final Log log = LogFactory.getLog(getClass()); public NotEqualToExpr(OperatorKey k) { this(k, -1); } public NotEqualToExpr(OperatorKey k, int rp) { super(k, rp); resultType = DataType.BOOLEAN; } @Override public String name() { return "Not Equal To" + "[" + DataType.findTypeName(resultType) + "]" + " - " + mKey.toString(); } @Override public void visit(PhyPlanVisitor v) throws VisitorException { v.visitNotEqualTo(this); } @Override public Result getNextBoolean() throws ExecException { Result left, right; switch (operandType) { case DataType.BYTEARRAY: case DataType.DOUBLE: case DataType.FLOAT: case DataType.BOOLEAN: case DataType.INTEGER: case DataType.BIGINTEGER: case DataType.BIGDECIMAL: case DataType.LONG: case DataType.DATETIME: case DataType.CHARARRAY: case DataType.TUPLE: case DataType.MAP: { Result r = accumChild(null, operandType); if (r != null) { return r; } left = lhs.getNext(operandType); right = rhs.getNext(operandType); return doComparison(left, right); } default: { int errCode = 2067; String msg = this.getClass().getSimpleName() + " does not know how to " + "handle type: " + DataType.findTypeName(operandType); throw new ExecException(msg, errCode, PigException.BUG); } } } @SuppressWarnings("unchecked") private Result doComparison(Result left, Result right) throws ExecException { if (left.returnStatus != POStatus.STATUS_OK) { return left; } if (right.returnStatus != POStatus.STATUS_OK) { return right; } // if either operand is null, the result should be // null if (left.result == null || right.result == null) { left.result = null; left.returnStatus = POStatus.STATUS_OK; return left; } if (left.result instanceof Comparable && right.result instanceof Comparable) { if (((Comparable) left.result).compareTo(right.result) != 0) { left.result = Boolean.TRUE; } else { left.result = Boolean.FALSE; } } else if (left.result instanceof HashMap && right.result instanceof HashMap) { HashMap leftMap = (HashMap) left.result; HashMap rightMap = (HashMap) right.result; if (leftMap.equals(rightMap)) { left.result = Boolean.FALSE; } else { left.result = Boolean.TRUE; } } else { throw new ExecException("The left side and right side has the different types"); } illustratorMarkup(null, left.result, (Boolean) left.result ? 0 : 1); return left; } @Override public NotEqualToExpr clone() throws CloneNotSupportedException { NotEqualToExpr clone = new NotEqualToExpr( new OperatorKey(mKey.scope, NodeIdGenerator.getGenerator().getNextNodeId(mKey.scope))); clone.cloneHelper(this); return clone; } }