Parse 接口 ParseResult类 ParseData 类

//ParseData类表示网页的数据，包含标题，meta标签等等。。。。

package org.apache.nutch.parse;

import org.apache.nutch.metadata.Metadata;
import org.apache.nutch.util.NutchConfiguration;


/** Data extracted from a page's content.
 * @see Parse#getData()
 */
public final class ParseData extends VersionedWritable {
  public static final String DIR_NAME = "parse_data";

  private final static byte VERSION = 5;

  private String title;
  private Outlink[] outlinks;
  private Metadata contentMeta;//存放源数据Map
  private Metadata parseMeta;//存放源数据的Map
  private ParseStatus status;
  private byte version = VERSION;
  
  

  public ParseData(ParseStatus status, String title, Outlink[] outlinks,
                   Metadata contentMeta) {
    this(status, title, outlinks, contentMeta, new Metadata());//构造时没设置parseMeta所以后面有setParseMeta()
  }
  
  public ParseData(ParseStatus status, String title, Outlink[] outlinks,
                   Metadata contentMeta, Metadata parseMeta) {
    this.status = status;
    this.title = title;
    this.outlinks = outlinks;
    this.contentMeta = contentMeta;
    this.parseMeta = parseMeta;
  }

 
  /** The original Metadata retrieved from content */
  public Metadata getContentMeta() { return contentMeta; }//这个方法可获取contentMeta后调用其put（）方法设值
  /**
   * Other content properties.
   * This is the place to find format-specific properties.
   * Different parser implementations for different content types will populate
   * this differently.
   */
  public Metadata getParseMeta() { return parseMeta; }//这个方法可获取parseMeta后调用其put（）方法设值
  
  public void setParseMeta(Metadata parseMeta) {//构造时没设置parseMeta所以有setParseMeta()
    this.parseMeta = parseMeta;
  }
  
  /**
   * Get a metadata single value.
   * This method first looks for the metadata value in the parse metadata. If no
   * value is found it the looks for the metadata in the content metadata.
   * （先从parseMeta这个Map中找，没有再找contentMeta这个Map，找到后返回）
   * @see #getContentMeta()
   * @see #getParseMeta()
   */
  public String getMeta(String name) {//先从parseMeta这个Map中找，没有再找contentMeta这个Map，找到后返回
    String value = parseMeta.get(name);
    if (value == null) {
      value = contentMeta.get(name);
    }
    return value;
  }
 
}

Parse接口：

package org.apache.nutch.parse;

/** The result of parsing a page's raw content.
 * @see Parser#getParse(Content)
 */
public interface Parse {
  
  /** The textual content of the page. This is indexed, searched, and used when
   * generating snippets.*/ 
  String getText();

  /** Other data extracted from the page. */
  ParseData getData();
  
  /** Indicates if the parse is coming from a url or a sub-url */
  boolean isCanonical();
}

 ParseResult类：

package org.apache.nutch.parse;

public class ParseResult implements Iterable> {
  private Map parseMap;//保存多个Parse实例的Map
  private String originalUrl;
  
  
  public static ParseResult createParseResult(String url, Parse parse) {
    ParseResult parseResult = new ParseResult(url);
    parseResult.put(new Text(url), new ParseText(parse.getText()), parse.getData());//调用（1）
    return parseResult;
  }
  public void put(Text key, ParseText text, ParseData data) {//(1)
    put(key.toString(), text, data);//调用（2）
  }
  public void put(String key, ParseText text, ParseData data) {//(2)
    parseMap.put(new Text(key), new ParseImpl(text, data, key.equals(originalUrl)));//存一条Parse实例到Map，key是页面url
  }
 
}

PaseResult内包含多个Parse实例（具体为ParseImpl的实例，ParseImpl实现了Parse接口，ParseImpl代表一个网页parse后的数据（result of parsing a page's raw content））

实现了Parse接口的ParseImpl类有public ParseData getData() { return data; }这个方法，此方法返回的是ParseData类的实例