学步园

public class Processor extends ModuleType {
//默认的下一个处理器
    private Processor defaultNextProcessor = null;
 /**
     * Perform processing on the given CrawlURI.
     *    处理一个链接
     * @param curi
     * @throws InterruptedException
     */
    public final void process(CrawlURI curi) throws InterruptedException {
        // by default, arrange for curi to proceed to next processor
        //设置当前处理器的下一个处理器
        curi.setNextProcessor(getDefaultNextProcessor(curi));

        // Check if this processor is enabled before processing
        try {
            if (!((Boolean) getAttribute(ATTR_ENABLED, curi)).booleanValue()) {
                return;
            }
        } catch (AttributeNotFoundException e) {
            logger.severe(e.getMessage());
        }

        if(rulesAccept(curi)) {
            innerProcess(curi); //留给子类实现
        } else {
            innerRejectProcess(curi);
        }
    }

        Processor previous = null;

        for (Iterator it = processorMap.iterator(null); it.hasNext();) {
            Processor p = (Processor) it.next();

            if (previous == null) {
                firstProcessor = p;
            } else {
                //设置前一个处理器的下一个处理器为当前处理器
                previous.setDefaultNextProcessor(p);
            }

            logger.info(
                "Processor: " + p.getName() + " --> " + p.getClass().getName());
            //当前处理器设置为前一个处理器
            previous = p;
        }
    }

    /** Set the processor chain that the URI should be working through after
     * finishing this one.
     * 设置下一个处理器
     * @param nextProcessorChain the chain that should be processed after this
     *        one.
     */
    public void setNextChain(ProcessorChain nextProcessorChain) {
        this.nextChain = nextProcessorChain;
    }

    /** Get the processor chain that the URI should be working through after
     * finishing this one.
     *
     * @return the next processor chain.
     */
    public ProcessorChain getNextProcessorChain() {
        return nextChain;
    }

    /** Get the first processor in the chain.
     * 获取第一个处理器
     * @return the first processor in the chain.
     */
    public Processor getFirstProcessor() {
        return firstProcessor;
    }

     /** Add a new chain of processors to the chain list.
     * 将所有的处理器链添加到Map中
     * This method takes a map of processors and wraps it in a ProcessorChain
     * object and adds it to the list of chains.
     *
     * @param processorMap the processor map to be added.
     */
    public void addProcessorMap(String name, MapType processorMap) {
        //由MapType生成一个处理器链
        ProcessorChain processorChain = new ProcessorChain(processorMap);
        ProcessorChain previousChain = getLastChain();
        if (previousChain != null) {
            //设置下一个处理器链
            previousChain.setNextChain(processorChain);
        }
        chainList.add(processorChain);
        chainMap.put(name, processorChain);
    }

    /** Get the first processor chain.
     * 获取第一个处理链
     * @return the first processor chain.
     */
    public ProcessorChain getFirstChain() {
        return (ProcessorChain) chainList.get(0);
    }

                while (currentCuri.nextProcessor() != null) {
                    setStep(STEP_ABOUT_TO_BEGIN_PROCESSOR);
                    Processor currentProcessor = getProcessor(currentCuri.nextProcessor());
                    currentProcessorName = currentProcessor.getName();
                    continueCheck();
//                    long memBefore = (Runtime.getRuntime().totalMemory()-Runtime.getRuntime().freeMemory())/1024;
                    //调用处理器处理链接
                    currentProcessor.process(currentCuri);
//                    long memAfter = (Runtime.getRuntime().totalMemory()-Runtime.getRuntime().freeMemory())/1024;
//                    System.out.println((memAfter-memBefore)+"K in "+currentProcessorName);
                }
            }
            setStep(STEP_DONE_WITH_PROCESSORS);
            currentProcessorName = "";
        } catch (RuntimeExceptionWrapper e) {
            // Workaround to get cause from BDB
            if(e.getCause() == null) {
                e.initCause(e.getCause());
            }
            recoverableProblem(e);
        } catch (AssertionError ae) {
            // This risks leaving crawl in fatally inconsistent state, 
            // but is often reasonable for per-Processor assertion problems 
            recoverableProblem(ae);
        } catch (RuntimeException e) {
            recoverableProblem(e);
        } catch (StackOverflowError err) {
            recoverableProblem(err);
        } catch (Error err) {
            // OutOfMemory and any others
            seriousError(err); 
        }