NamedParameterUtils.parseSqlStatement should parse :{x} style parameter correctly

In my opinion, we should parse ":{x}" style parameter as "x" is parameter using "NamedParameterUtils.parseSqlStatement",
so the condition "j - i > 2" is the correct condition, not "j - i > 3", because if "i" is the index of
":" in ":{x}", and "j" is the index of "}" in ":{x}",  "j - i == 3" is true.
Also add a test case for SPR-16663.

(cherry picked from commit 82cb5db)

Author: nkjackzhang

spring-jdbc/src/main/java/org/springframework/jdbc/core/namedparam/NamedParameterUtils.java

@@ -41,23 +41,21 @@
 public abstract class NamedParameterUtils {
 
 	/**
-	 * Set of characters that qualify as parameter separators,
-	 * indicating that a parameter name in a SQL String has ended.
+	 * Set of characters that qualify as comment or quotes starting characters.
 	 */
-	private static final char[] PARAMETER_SEPARATORS =
-			new char[] {'"', '\'', ':', '&', ',', ';', '(', ')', '|', '=', '+', '-', '*', '%', '/', '\\', '<', '>', '^'};
+	private static final String[] START_SKIP = new String[] {"'", "\"", "--", "/*"};
 
 	/**
-	 * Set of characters that qualify as comment or quotes starting characters.
+	 * Set of characters that at are the corresponding comment or quotes ending characters.
 	 */
-	private static final String[] START_SKIP =
-			new String[] {"'", "\"", "--", "/*"};
+	private static final String[] STOP_SKIP = new String[] {"'", "\"", "\n", "*/"};
 
 	/**
-	 * Set of characters that at are the corresponding comment or quotes ending characters.
+	 * Set of characters that qualify as parameter separators,
+	 * indicating that a parameter name in a SQL String has ended.
 	 */
-	private static final String[] STOP_SKIP =
-			new String[] {"'", "\"", "\n", "*/"};
+	private static final char[] PARAMETER_SEPARATORS =
+			new char[] {'"', '\'', ':', '&', ',', ';', '(', ')', '|', '=', '+', '-', '*', '%', '/', '\\', '<', '>', '^'};
 
 
 	//-------------------------------------------------------------------------
@@ -109,7 +107,7 @@ public static ParsedSql parseSqlStatement(final String sql) {
 				String parameter = null;
 				if (j < statement.length && c == ':' && statement[j] == '{') {
 					// :{x} style parameter
-					while (j < statement.length && !('}' == statement[j])) {
+					while (j < statement.length && '}' != statement[j]) {
 						j++;
 						if (':' == statement[j] || '{' == statement[j]) {
 							throw new InvalidDataAccessApiUsageException("Parameter name contains invalid character '" +
@@ -120,7 +118,7 @@ public static ParsedSql parseSqlStatement(final String sql) {
 						throw new InvalidDataAccessApiUsageException(
 								"Non-terminated named parameter declaration at position " + i + " in statement: " + sql);
 					}
-					if (j - i > 3) {
+					if (j - i > 2) {
 						parameter = sql.substring(i + 2, j);
 						namedParameterCount = addNewNamedParameter(namedParameters, namedParameterCount, parameter);
 						totalParameterCount = addNamedParameter(parameterList, totalParameterCount, escapes, i, j + 1, parameter);
@@ -200,7 +198,7 @@ private static int skipCommentsAndQuotes(char[] statement, int position) {
 			if (statement[position] == START_SKIP[i].charAt(0)) {
 				boolean match = true;
 				for (int j = 1; j < START_SKIP[i].length(); j++) {
-					if (!(statement[position + j] == START_SKIP[i].charAt(j))) {
+					if (statement[position + j] != START_SKIP[i].charAt(j)) {
 						match = false;
 						break;
 					}
@@ -216,7 +214,7 @@ private static int skipCommentsAndQuotes(char[] statement, int position) {
 									// last comment not closed properly
 									return statement.length;
 								}
-								if (!(statement[m + n] == STOP_SKIP[i].charAt(n))) {
+								if (statement[m + n] != STOP_SKIP[i].charAt(n)) {
 									endMatch = false;
 									break;
 								}

spring-jdbc/src/test/java/org/springframework/jdbc/core/namedparam/NamedParameterUtilsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -253,6 +253,18 @@ public void parseSqlStatementWithEmptyBracketsOrBracketsInQuotes() throws Except
 		assertEquals(expectedSql2, finalSql2);
 	}
 
+	@Test
+	public void parseSqlStatementWithSingleLetterInBrackets() {
+		String expectedSql = "select foo from bar where baz = b?z";
+		String sql = "select foo from bar where baz = b:{p}z";
+		
+		ParsedSql parsedSql = NamedParameterUtils.parseSqlStatement(sql);
+		assertEquals(1, parsedSql.getParameterNames().size());
+		assertEquals("p", parsedSql.getParameterNames().get(0));
+		String finalSql = NamedParameterUtils.substituteNamedParameters(parsedSql, null);
+		assertEquals(expectedSql, finalSql);
+	}
+
 	@Test  // SPR-2544
 	public void parseSqlStatementWithLogicalAnd() {
 		String expectedSql = "xxx & yyyy";