IsEmptyTagHandler.java

/*
 * Copyright 2004-2022 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.
 * You may obtain a copy of the License at
 *
 *    https://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.ibatis.sqlmap.engine.mapping.sql.dynamic.elements;

import com.ibatis.common.beans.Probe;
import com.ibatis.common.beans.ProbeFactory;

import java.lang.reflect.Array;
import java.util.Collection;

/**
 * The Class IsEmptyTagHandler.
 */
public class IsEmptyTagHandler extends ConditionalTagHandler {

  /** The Constant PROBE. */
  private static final Probe PROBE = ProbeFactory.getProbe();

  @Override
  public boolean isCondition(SqlTagContext ctx, SqlTag tag, Object parameterObject) {
    if (parameterObject == null) {
      return true;
    } else {
      String prop = getResolvedProperty(ctx, tag);
      Object value;
      if (prop != null) {
        value = PROBE.getObject(parameterObject, prop);
      } else {
        value = parameterObject;
      }
      if (value instanceof Collection) {
        return value == null || ((Collection) value).size() < 1;
      } else if (value != null && value.getClass().isArray()) {
        return Array.getLength(value) == 0;
      } else {
        return value == null || String.valueOf(value).equals("");
      }
    }
  }

}