content: /*
   * Copyright 1999-2018 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.proxy.jdbc;
  
  import com.alibaba.druid.filter.FilterChain;
  
  import java.sql.SQLException;
  import java.sql.Wrapper;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * @author wenshao [szujobs@hotmail.com]
   */
  public abstract class WrapperProxyImpl implements WrapperProxy {
      private final Wrapper raw;
  
      private final long id;
  
      private Map<String, Object> attributes; // 不需要线程安全
  
      public WrapperProxyImpl(Wrapper wrapper, long id) {
          this.raw = wrapper;
          this.id = id;
      }
  
      public long getId() {
          return this.id;
      }
  
      public Object getRawObject() {
          return raw;
      }
  
      public abstract FilterChain createChain();
  
      @Override
      public boolean isWrapperFor(Class<?> iface) throws SQLException {
          if (iface == null) {
              return false;
          }
  
          if (iface == this.getClass()) {
              return true;
          }
  
          FilterChain chain = createChain();
          return chain.isWrapperFor(raw, iface);
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public <T> T unwrap(Class<T> iface) throws SQLException {
          if (iface == null) {
              return null;
          }
  
          if (iface == this.getClass()) {
              return (T) this;
          }
  
          return createChain().unwrap(raw, iface);
      }
  
      public int getAttributesSize() {
          if (attributes == null) {
              return 0;
          }
  
          return attributes.size();
      }
  
      public void clearAttributes() {
          if (this.attributes == null) {
              return;
          }
  
          this.attributes.clear();
      }
  
      public Map<String, Object> getAttributes() {
          if (attributes == null) {
              attributes = new HashMap<String, Object>(4);
          }
          return this.attributes;
      }
  
      public void putAttribute(String key, Object value) {
          if (attributes == null) {
              attributes = new HashMap<String, Object>(4);
          }
          this.attributes.put(key, value);
      }
  
      public Object getAttribute(String key) {
          if (attributes == null) {
              return null;
          }
  
          return this.attributes.get(key);
      }
  
  }
  