package us.codecraft.webmagic.pipeline;
   
   import com.alibaba.fastjson.JSON;
   import org.apache.commons.codec.digest.DigestUtils;
   import org.apache.commons.lang3.builder.ToStringBuilder;
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   import us.codecraft.webmagic.Task;
   import us.codecraft.webmagic.model.HasKey;
  import us.codecraft.webmagic.utils.FilePersistentBase;
  
  import java.io.FileWriter;
  import java.io.IOException;
  import java.io.PrintWriter;
  
  /**
   * Store results objects (page models) to files in JSON format.<br>
   * Use model.getKey() as file name if the model implements HasKey.<br>
   * Otherwise use SHA1 as file name.
   *
   * @author code4crafter@gmail.com <br>
   * @since 0.2.0
   */
  public class JsonFilePageModelPipeline extends FilePersistentBase implements PageModelPipeline {
  
      private Logger logger = LoggerFactory.getLogger(getClass());
  
      /**
       * new JsonFilePageModelPipeline with default path "/data/webmagic/"
       */
      public JsonFilePageModelPipeline() {
          setPath("/data/webmagic/");
      }
  
      public JsonFilePageModelPipeline(String path) {
          setPath(path);
      }
  
      @Override
      public void process(Object o, Task task) {
          String path = this.path + PATH_SEPERATOR + task.getUUID() + PATH_SEPERATOR;
          try {
              String filename;
              if (o instanceof HasKey) {
                  filename = path + ((HasKey) o).key() + ".json";
              } else {
                  filename = path + DigestUtils.md5Hex(ToStringBuilder.reflectionToString(o)) + ".json";
              }
              PrintWriter printWriter = new PrintWriter(new FileWriter(getFile(filename)));
              printWriter.write(JSON.toJSONString(o));
              printWriter.close();
          } catch (IOException e) {
              logger.warn("write file error", e);
          }
      }
  }