IWorkloadStorable接口

IWorkloadStorable接口：

Spider的主要工作之一就是处理访问过的和将要访问的站点的列表，称为作业。IWorkloadStorable接口定义的对象就可以存入和取出作业中的网页.

最主要的两个方法：

public String assignWorkload();//取出作业里的网页

public void addWorkload(String url);//向作业里存入网页；

除此以外，还有其他的一些方法和成员变量:

1. package com.heaton.bot;
2.
3. /**
4. * This interface defines a class that can
5. * be used to store a spider's workload（作业）.
6. * The Bot package currently supports two
7. * different workload stores:
8. *
9. * SpiderInternalWorkload - Stores the
10. * contents of the workload in memory.
11. *
12. * SpiderSQLWorkload - Stores the contents
13. * of the workload in an SQL database.
14. */
15. public interface IWorkloadStorable {
16.
17. /**
18. * A workload entry has a status of running
19. * if the spider worker is opening or downloading
20. * that page. This state usually goes to COMPLETE
21. * or ERROR.
22. */
23. public static final char RUNNING = 'R';
24.
25. /**
26. * Processing of this URL resulted in an
27. * error.
28. */
29. public static final char ERROR = 'E';
30.
31. /**
32. * This URL is waiting for a spider
33. * worker to take it on.
34. */
35. public static final char WAITING = 'W';
36.
37. /**
38. * This page is complete and should not
39. * be redownloaded.
40. */
41. public static final char COMPLETE = 'C';
42.
43. /**
44. * The status is unknown.
45. */
46. public static final char UNKNOWN = 'U';
47.
48. /**
49. * Call this method to request a URL
50. * to process. This method will return
51. * a WAITING URL and mark it as RUNNING.
52. *
53. * @return The URL that was assigned（指定，分配）.
54. * 相当于getworkload（）。
55. */
56. public String assignWorkload();
57.
58. /**
59. * Add a new URL to the workload, and
60. * assign it a status of WAITING.
61. *
62. * @param url The URL to be added.
63. */
64. public void addWorkload(String url);
65.
66. /**
67. * Called to mark this URL as either
68. * COMPLETE or ERROR.
69. *
70. * @param url The URL to complete.
71. * @param error true - assign this workload a status of ERROR.
72. * false - assign this workload a status of COMPLETE.
73. */
74. public void completeWorkload(String url,boolean error);
75.
76. /**
77. * Get the status of a URL.
78. *
79. * @param url Returns either RUNNING, ERROR
80. * WAITING, or COMPLETE. If the URL
81. * does not exist in the database,
82. * the value of UNKNOWN is returned.
83. * @return Returns either RUNNING,ERROR,
84. * WAITING,COMPLETE or UNKNOWN.
85. */
86. public char getURLStatus(String url);
87.
88. /**
89. * Clear the contents of the workload store.
90. */
91. public void clear();
92. }
93.

其他几个方法不是常用到，倒是那几个状态变量可以留作理清思路之用。

That‘s OK！