QueueScheduler (webmagic 0.10.3 API)

java.lang.Object
- us.codecraft.webmagic.scheduler.DuplicateRemovedScheduler
- - us.codecraft.webmagic.scheduler.QueueScheduler

All Implemented Interfaces:

MonitorableScheduler, Scheduler
```
public class QueueScheduler
extends DuplicateRemovedScheduler
implements MonitorableScheduler
```
Basic Scheduler implementation.
Store urls to fetch in LinkedBlockingQueue and remove duplicate urls by HashMap. Note: if you use this QueueScheduler with Site.getCycleRetryTimes() enabled, you may encountered dead-lock when the queue is full.

Since:

0.1.0

Author:

code4crafter@gmail.com

Field Summary
- Fields inherited from class us.codecraft.webmagic.scheduler.DuplicateRemovedScheduler
  logger

Constructor Summary

Constructors
Constructor Description

QueueScheduler()

QueueScheduler(int capacity)
Creates a QueueScheduler with the given (fixed) capacity.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`getLeftRequestsCount(Task task)`
`int`	`getTotalRequestsCount(Task task)`
`Request`	`poll(Task task)`	get an url to crawl
`void`	`pushWhenNoDuplicate(Request request, Task task)`

Methods inherited from class us.codecraft.webmagic.scheduler.DuplicateRemovedScheduler
getDuplicateRemover, noNeedToRemoveDuplicate, push, setDuplicateRemover, shouldReserved

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface us.codecraft.webmagic.scheduler.Scheduler
push

- Constructor Detail
  - QueueScheduler
```
public QueueScheduler()
```
  - QueueScheduler
```
public QueueScheduler(int capacity)
```
    Creates a QueueScheduler with the given (fixed) capacity.
    
    Parameters:
    
    capacity - the capacity of this queue, see LinkedBlockingQueue(int)
    
    Since:
    
    0.8.0
- Method Detail
  - pushWhenNoDuplicate
```
public void pushWhenNoDuplicate(Request request,
                                Task task)
```
    Overrides:
    
    pushWhenNoDuplicate in class DuplicateRemovedScheduler
  - poll
```
public Request poll(Task task)
```
    Description copied from interface: Scheduler
    
    get an url to crawl
    
    Specified by:
    
    poll in interface Scheduler
    
    Parameters:
    
    task - the task of spider
    
    Returns:
    
    the url to crawl
  - getLeftRequestsCount
```
public int getLeftRequestsCount(Task task)
```
    Specified by:
    
    getLeftRequestsCount in interface MonitorableScheduler
  - getTotalRequestsCount
```
public int getTotalRequestsCount(Task task)
```
    Specified by:
    
    getTotalRequestsCount in interface MonitorableScheduler