sql parser refactor

src/main/java/com/alibaba/druid/sql/ast/expr/SQLVariantRefExpr.java

@@ -26,10 +26,12 @@ public class SQLVariantRefExpr extends SQLExprImpl {
 
     private boolean           global           = false;
 
+    private int               index            = -1;
+
     public SQLVariantRefExpr(String name){
         this.name = name;
     }
-    
+
     public SQLVariantRefExpr(String name, boolean global){
         this.name = name;
         this.global = global;
@@ -39,6 +41,14 @@ public class SQLVariantRefExpr extends SQLExprImpl {
 
     }
 
+    public int getIndex() {
+        return index;
+    }
+
+    public void setIndex(int index) {
+        this.index = index;
+    }
+
     public String getName() {
         return this.name;
     }

src/main/java/com/alibaba/druid/sql/parser/Lexer.java

@@ -82,6 +82,8 @@ public class Lexer {
      */
     private boolean                            allowComment = true;
 
+    private int                                varIndex     = -1;
+
     public Lexer(String input){
         this(input, true);
     }
@@ -93,6 +95,10 @@ public class Lexer {
     public void setAllowComment(boolean allowComment) {
         this.allowComment = allowComment;
     }
+    
+    public int nextVarIndex() {
+        return ++varIndex;
+    }
 
     private static class SavePoint {
 
@@ -185,7 +191,7 @@ public class Lexer {
     public final Token token() {
         return token;
     }
-    
+
     public String info() {
         return this.token + " " + this.stringVal();
     }
@@ -507,11 +513,11 @@ public class Lexer {
                     token = LITERAL_CHARS;
                     break;
                 } else {
-                	if (!hasSpecial) {
-	                    System.arraycopy(buf, np + 1, sbuf, 0, sp);
-	                    hasSpecial = true;
-                	}
-                	putChar('\'');
+                    if (!hasSpecial) {
+                        System.arraycopy(buf, np + 1, sbuf, 0, sp);
+                        hasSpecial = true;
+                    }
+                    putChar('\'');
                     continue;
                 }
             }

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -356,7 +356,9 @@ public class SQLExprParser extends SQLParser {
                 break;
             case QUES:
                 lexer.nextToken();
-                sqlExpr = new SQLVariantRefExpr("?");
+                SQLVariantRefExpr quesVarRefExpr = new SQLVariantRefExpr("?");
+                quesVarRefExpr.setIndex(lexer.nextVarIndex());
+                sqlExpr = quesVarRefExpr;
                 break;
             case LEFT:
                 sqlExpr = new SQLIdentifierExpr("LEFT");

src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitor.java

@@ -4,8 +4,6 @@ import java.util.List;
 
 public interface SQLEvalVisitor extends SQLASTVisitor {
 
-    public static final String EVAL_VAR_INDEX = "eval.varIndex";
-
     public static final String EVAL_VALUE     = "eval.value";
 
     List<Object> getParameters();

src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorUtils.java

@@ -1,7 +1,6 @@
 package com.alibaba.druid.sql.visitor;
 
 import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
-import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VAR_INDEX;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
@@ -104,16 +103,12 @@ public class SQLEvalVisitorUtils {
         
         Map<String, Object> attributes = x.getAttributes();
         
-        Integer varIndex = (Integer) attributes.get(EVAL_VAR_INDEX);
-        if (varIndex == null) {
-            varIndex = visitor.incrementAndGetVariantIndex();
-            x.putAttribute(EVAL_VAR_INDEX, varIndex);
-        }
+        int varIndex = x.getIndex();
 
-        if (visitor.getParameters().size() > 0) {
+        if (varIndex != -1 && visitor.getParameters().size() > varIndex) {
             boolean containsValue = attributes.containsKey(EVAL_VALUE);
             if (!containsValue) {
-                Object value = visitor.getParameters().get(varIndex.intValue());
+                Object value = visitor.getParameters().get(varIndex);
                 attributes.put(EVAL_VALUE, value);
             }
         }