Downloader (webmagic 0.10.3 API)

All Known Implementing Classes:

AbstractDownloader, HttpClientDownloader, PhantomJSDownloader, SeleniumDownloader
```
public interface Downloader
```
Downloader is the part that downloads web pages and store in Page object.
Downloader has setThread(int) method because downloader is always the bottleneck of a crawler, there are always some mechanisms such as pooling in downloader, and pool size is related to thread numbers.

Since:

0.1.0

Author:

code4crafter@gmail.com

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Page`	`download(Request request, Task task)`	Downloads web pages and store in Page object.
`void`	`setThread(int threadNum)`	Tell the downloader how many threads the spider used.

- Method Detail
  - download
```
Page download(Request request,
              Task task)
```
    Downloads web pages and store in Page object.
    
    Parameters:
    
    request - request
    
    task - task
    
    Returns:
    
    page
  - setThread
```
void setThread(int threadNum)
```
    Tell the downloader how many threads the spider used.
    
    Parameters:
    
    threadNum - number of threads