content: /*
   * Copyright 1999-2017 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 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.util.StringUtils;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
  
  /**
   * @author lizongbo
   * @see <a href="https://github.com/alibaba/druid/issues/5477">Issue来源</a>
   * @see <a href="https://dev.mysql.com/doc/refman/8.0/en/string-functions.html#function_replace">mysql replace函数</a>
   */
  public class Replace implements Function {
      public static final Replace instance = new Replace();
  
      public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
          if (x.getArguments().size() != 3) {
              return SQLEvalVisitor.EVAL_ERROR;
          }
          List<String> list = new ArrayList<>();
          for (SQLExpr item : x.getArguments()) {
              item.accept(visitor);
              Object param0Value = item.getAttributes().get(EVAL_VALUE);
              if (param0Value == null) {
                  return SQLEvalVisitor.EVAL_ERROR;
              }
              String strValue = null;
              if (param0Value != null && param0Value != SQLEvalVisitor.EVAL_VALUE_NULL) {
                  strValue = param0Value.toString();
              }
              list.add(strValue);
          }
          if (list.get(0) == null || list.get(1) == null || list.get(2) == null) {
              return list.get(0);
          }
          //暂时使用java String的replace方法,mysql replace函数是不支持正则表达式的
          return StringUtils.replaceAll(list.get(0), list.get(1), list.get(2));
      }
  }
  