refactor

src/main/java/com/alibaba/druid/wall/WallProvider.java

@@ -0,0 +1,103 @@
+package com.alibaba.druid.wall;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.parser.ParserException;
+import com.alibaba.druid.sql.parser.SQLStatementParser;
+import com.alibaba.druid.sql.parser.Token;
+
+public abstract class WallProvider {
+
+    // Dummy value to associate with an Object in the backing Map
+    private static final Object           PRESENT           = new Object();
+
+    private LinkedHashMap<String, Object> whiteList;
+
+    private int                           whileListMaxSize  = 1024;
+
+    private int                           whiteSqlMaxLength = 1024;        // 1k
+
+    protected final WallConfig            config;
+
+    public WallProvider(WallConfig config){
+        this.config = config;
+    }
+
+    public WallConfig getConfig() {
+        return config;
+    }
+
+    public synchronized void addWhiteSql(String sql) {
+        if (whiteList == null) {
+            whiteList = new LinkedHashMap<String, Object>(whileListMaxSize, 0.75f, true);
+        }
+
+        whiteList.put(sql, PRESENT);
+    }
+
+    public synchronized boolean whiteContains(String sql) {
+        if (whiteList == null) {
+            return false;
+        }
+
+        return whiteList.get(sql) != null;
+    }
+
+    public abstract SQLStatementParser createParser(String sql);
+
+    public abstract WallVisitor createWallVisitor();
+    
+    public boolean checkValid(String sql) {
+        return check(sql).size() == 0;
+    }
+
+    public List<Violation> check(String sql) {
+        // first step, check whiteList
+        boolean isWhite = whiteContains(sql);
+        if (isWhite) {
+            return Collections.emptyList();
+        }
+
+        SQLStatementParser parser = createParser(sql);
+        parser.getLexer().setAllowComment(false); // permit comment
+
+        List<SQLStatement> statementList = new ArrayList<SQLStatement>();
+
+        try {
+            parser.parseStatementList(statementList);
+        } catch (ParserException e) {
+            return Collections.<Violation> singletonList(new IllegalSQLObjectViolation(sql));
+        }
+
+        if (parser.getLexer().token() != Token.EOF) {
+            return Collections.<Violation> singletonList(new IllegalSQLObjectViolation(sql));
+        }
+
+        if (statementList.size() > 1) {
+            return Collections.<Violation> singletonList(new IllegalSQLObjectViolation(sql));
+        }
+
+        SQLStatement stmt = statementList.get(0);
+
+        WallVisitor visitor = createWallVisitor();
+
+        try {
+            stmt.accept(visitor);
+        } catch (ParserException e) {
+            return Collections.<Violation> singletonList(new IllegalSQLObjectViolation(sql));
+        }
+
+        if (visitor.getViolations().size() == 0) {
+            if (sql.length() < whiteSqlMaxLength) {
+                this.addWhiteSql(sql);
+            }
+        }
+
+        return visitor.getViolations();
+    }
+
+}