From 3e3d5904239179bb4806267bf154b83edd64226a Mon Sep 17 00:00:00 2001
From: wenshao <szujobs@hotmail.com>
Date: Wed, 10 Aug 2016 18:02:21 +0800
Subject: [PATCH] remvoed commons-lang dependency. #issue 1364

---
 .../com/alibaba/druid/sql/parser/Lexer.java   |  3 +-
 .../com/alibaba/druid/util/StringUtils.java   | 96 +++++++++++++++++++
 2 files changed, 98 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/alibaba/druid/sql/parser/Lexer.java b/src/main/java/com/alibaba/druid/sql/parser/Lexer.java
index a9638f4421..e166d2c99f 100644
--- a/src/main/java/com/alibaba/druid/sql/parser/Lexer.java
+++ b/src/main/java/com/alibaba/druid/sql/parser/Lexer.java
@@ -39,6 +39,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import com.alibaba.druid.util.StringUtils;
 import org.apache.commons.lang.math.NumberUtils;
 
 /**
@@ -1285,7 +1286,7 @@ public class Lexer {
 
     public BigDecimal decimalValue() {
         String value = subString(mark, bufPos);
-        if (!NumberUtils.isNumber(value)){
+        if (!StringUtils.isNumber(value)){
             throw new ParserException(value+" is not a number!");
         }
         return new BigDecimal(value.toCharArray());
diff --git a/src/main/java/com/alibaba/druid/util/StringUtils.java b/src/main/java/com/alibaba/druid/util/StringUtils.java
index ed16734f15..1c907a2621 100644
--- a/src/main/java/com/alibaba/druid/util/StringUtils.java
+++ b/src/main/java/com/alibaba/druid/util/StringUtils.java
@@ -146,4 +146,100 @@ public class StringUtils {
         }
         return h;
     }
+
+    public static boolean isNumber(String str) {
+        if (isEmpty(str)) {
+            return false;
+        }
+        char[] chars = str.toCharArray();
+        int sz = chars.length;
+        boolean hasExp = false;
+        boolean hasDecPoint = false;
+        boolean allowSigns = false;
+        boolean foundDigit = false;
+        // deal with any possible sign up front
+        int start = (chars[0] == '-') ? 1 : 0;
+        if (sz > start + 1) {
+            if (chars[start] == '0' && chars[start + 1] == 'x') {
+                int i = start + 2;
+                if (i == sz) {
+                    return false; // str == "0x"
+                }
+                // checking hex (it can't be anything else)
+                for (; i < chars.length; i++) {
+                    if ((chars[i] < '0' || chars[i] > '9')
+                            && (chars[i] < 'a' || chars[i] > 'f')
+                            && (chars[i] < 'A' || chars[i] > 'F')) {
+                        return false;
+                    }
+                }
+                return true;
+            }
+        }
+        sz--; // don't want to loop to the last char, check it afterwords
+        // for type qualifiers
+        int i = start;
+        // loop to the next to last char or to the last char if we need another digit to
+        // make a valid number (e.g. chars[0..5] = "1234E")
+        while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) {
+            if (chars[i] >= '0' && chars[i] <= '9') {
+                foundDigit = true;
+                allowSigns = false;
+
+            } else if (chars[i] == '.') {
+                if (hasDecPoint || hasExp) {
+                    // two decimal points or dec in exponent
+                    return false;
+                }
+                hasDecPoint = true;
+            } else if (chars[i] == 'e' || chars[i] == 'E') {
+                // we've already taken care of hex.
+                if (hasExp) {
+                    // two E's
+                    return false;
+                }
+                if (!foundDigit) {
+                    return false;
+                }
+                hasExp = true;
+                allowSigns = true;
+            } else if (chars[i] == '+' || chars[i] == '-') {
+                if (!allowSigns) {
+                    return false;
+                }
+                allowSigns = false;
+                foundDigit = false; // we need a digit after the E
+            } else {
+                return false;
+            }
+            i++;
+        }
+        if (i < chars.length) {
+            if (chars[i] >= '0' && chars[i] <= '9') {
+                // no type qualifier, OK
+                return true;
+            }
+            if (chars[i] == 'e' || chars[i] == 'E') {
+                // can't have an E at the last byte
+                return false;
+            }
+            if (!allowSigns
+                    && (chars[i] == 'd'
+                    || chars[i] == 'D'
+                    || chars[i] == 'f'
+                    || chars[i] == 'F')) {
+                return foundDigit;
+            }
+            if (chars[i] == 'l'
+                    || chars[i] == 'L') {
+                // not allowing L with an exponent
+                return foundDigit && !hasExp;
+            }
+            // last character is illegal
+            return false;
+        }
+        // allowSigns is true iff the val ends in 'E'
+        // found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
+        return !allowSigns && foundDigit;
+    }
 }