/*
* Copyright 1999-2011 Alibaba Group Holding Ltd.
*
* Licensed 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 com.alibaba.druid.sql.visitor.functions;
import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VALUE_NULL;
import java.math.BigDecimal;
import java.math.BigInteger;
import com.alibaba.druid.sql.ast.SQLExpr;
import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
import com.alibaba.druid.sql.visitor.SQLEvalVisitor;
import com.alibaba.druid.sql.visitor.SQLEvalVisitorUtils;
import com.alibaba.druid.util.Utils;
public class OneParamFunctions implements Function {
public final static OneParamFunctions instance = new OneParamFunctions();
public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
if (x.getParameters().size() == 0) {
return SQLEvalVisitor.EVAL_ERROR;
}
SQLExpr param = x.getParameters().get(0);
param.accept(visitor);
Object paramValue = param.getAttributes().get(EVAL_VALUE);
if (paramValue == null) {
return SQLEvalVisitor.EVAL_ERROR;
}
if (paramValue == EVAL_VALUE_NULL) {
return EVAL_VALUE_NULL;
}
String method = x.getMethodName();
if ("md5".equalsIgnoreCase(method)) {
String text = paramValue.toString();
return Utils.md5(text);
}
if ("bit_count".equalsIgnoreCase(method)) {
if (paramValue instanceof BigInteger) {
return ((BigInteger) paramValue).bitCount();
}
if (paramValue instanceof BigDecimal) {
BigDecimal decimal = (BigDecimal) paramValue;
BigInteger bigInt = decimal.setScale(0, BigDecimal.ROUND_HALF_UP).toBigInteger();
return bigInt.bitCount();
}
Long val = SQLEvalVisitorUtils.castToLong(paramValue);
return Long.bitCount(val);
}
if ("soundex".equalsIgnoreCase(method)) {
String text = paramValue.toString();
return soundex(text);
}
if ("space".equalsIgnoreCase(method)) {
int intVal = SQLEvalVisitorUtils.castToInteger(paramValue);
char[] chars = new char[intVal];
for (int i = 0; i < chars.length; ++i) {
chars[i] = ' ';
}
return new String(chars);
}
throw new UnsupportedOperationException(method);
}
public static String soundex(String str) {
if (str == null) {
return null;
}
str = clean(str);
if (str.length() == 0) {
return str;
}
char out[] = {'0', '0', '0', '0'};
char last, mapped;
int incount = 1, count = 1;
out[0] = str.charAt(0);
// getMappingCode() throws IllegalArgumentException
last = getMappingCode(str, 0);
while ((incount < str.length()) && (count < out.length)) {
mapped = getMappingCode(str, incount++);
if (mapped != 0) {
if ((mapped != '0') && (mapped != last)) {
out[count++] = mapped;
}
last = mapped;
}
}
return new String(out);
}
static String clean(String str) {
if (str == null || str.length() == 0) {
return str;
}
int len = str.length();
char[] chars = new char[len];
int count = 0;
for (int i = 0; i < len; i++) {
if (Character.isLetter(str.charAt(i))) {
chars[count++] = str.charAt(i);
}
}
if (count == len) {
return str.toUpperCase(java.util.Locale.ENGLISH);
}
return new String(chars, 0, count).toUpperCase(java.util.Locale.ENGLISH);
}
private static char getMappingCode(String str, int index) {
// map() throws IllegalArgumentException
char mappedChar = map(str.charAt(index));
// HW rule check
if (index > 1 && mappedChar != '0') {
char hwChar = str.charAt(index - 1);
if ('H' == hwChar || 'W' == hwChar) {
char preHWChar = str.charAt(index - 2);
char firstCode = map(preHWChar);
if (firstCode == mappedChar || 'H' == preHWChar || 'W' == preHWChar) {
return 0;
}
}
}
return mappedChar;
}
private static char map(char ch) {
String soundexMapping = "01230120022455012623010202";
int index = ch - 'A';
if (index < 0 || index >= soundexMapping.length()) {
throw new IllegalArgumentException("The character is not mapped: " + ch);
}
return soundexMapping.charAt(index);
}
}