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使用SAXParser从XML检索HTML编码的文本

师曦
2023-03-14
问题内容

这是我第一次使用SAXParser(我在Android中使用它,但我认为这对这个特定问题没有影响),并且我正尝试从RSS
feed中读取数据。到目前为止,它在很大程度上对我来说非常有用,但是当它到达包含HTML编码文本(例如&lt;a href="http://...)的标签时,我遇到了麻烦。该characters()方法仅将读&lt;<,然后将下一组字符视为一个单独的实体,而不是立即获取全部内容。我希望它按原样阅读,而无需实际翻译HTML。我在文档处理程序中使用的代码(缩短了)如下所示:

@Override
    public void startElement(String uri, String localName, String qName, Attributes attrs) throws SAXException {
        if (localName.equalsIgnoreCase("channel")) {
            inChannel = true;
        }
        if (inChannel) {
            if (newFeed == null) newFeed = new Feed();

            if (localName.equalsIgnoreCase("image")) {
                if (feedImage == null) feedImage = new Image();
                inImage = true;
            }

            if (localName.equalsIgnoreCase("item")) {
                if (newItem == null) newItem = new Item();
                if (itemList == null) itemList = new ArrayList<Item>();
                inItem = true;
            }
        }   
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        if(!inItem) {
            if(!inImage) {
                if(inChannel) {
                    //Reached end of feed
                    if(localName.equalsIgnoreCase("channel")) {
                        newFeed.setItems((ArrayList<Item>)itemList);
                        finalFeed = newFeed;
                        newFeed = null;                     
                        inChannel = false;
                        return;
                    } else if(localName.equalsIgnoreCase("title")) {
                        newFeed.setTitle(currentValue); return;
                    } else if(localName.equalsIgnoreCase("link")) {
                        newFeed.setLink(currentValue); return;
                    } else if(localName.equalsIgnoreCase("description")) {
                        newFeed.setDescription(currentValue); return;
                    } else if(localName.equalsIgnoreCase("language")) {
                        newFeed.setLanguage(currentValue); return;
                    } else if(localName.equalsIgnoreCase("copyright")) {
                        newFeed.setCopyright(currentValue); return;
                    } else if(localName.equalsIgnoreCase("category")) {
                        newFeed.addCategory(currentValue); return;
                    }                       
                }
            }
            else { //is inImage
                //finished with feed image
                if(localName.equalsIgnoreCase("image")) {
                    newFeed.setImage(feedImage);
                    feedImage = null;
                    inImage = false;
                    return;
                } else if (localName.equalsIgnoreCase("url")) {
                    feedImage.setUrl(currentValue); return;
                } else if (localName.equalsIgnoreCase("title")) {
                    feedImage.setTitle(currentValue); return;
                } else if (localName.equalsIgnoreCase("link")) {
                    feedImage.setLink(currentValue); return;
                }
            }
        }
        else { //is inItem
            //finished with news item
            if (localName.equalsIgnoreCase("item")) {
                itemList.add(newItem);
                newItem = null;
                inItem = false;
                return;
            } else if (localName.equalsIgnoreCase("title")) {
                newItem.setTitle(currentValue); return;
            } else if (localName.equalsIgnoreCase("link")) {
                newItem.setLink(currentValue); return;
            } else if (localName.equalsIgnoreCase("description")) {
                newItem.setDescription(currentValue); return;
            } else if (localName.equalsIgnoreCase("author")) {
                newItem.setAuthor(currentValue); return;
            } else if (localName.equalsIgnoreCase("category")) {
                newItem.addCategory(currentValue); return;
            } else if (localName.equalsIgnoreCase("comments")) {
                newItem.setComments(currentValue); return;
            } /*else if (localName.equalsIgnoreCase("enclosure")) {
                 To be implemented later
            }*/ else if (localName.equalsIgnoreCase("guid")) {
                newItem.setGuid(currentValue); return;
            } else if (localName.equalsIgnoreCase("pubDate")) {
                newItem.setPubDate(currentValue); return;
            }           
        }
    }

    @Override
    public void characters(char[] ch, int start, int length) {
        currentValue = new String(ch, start, length);
    }

我要解析的RSS feed的一个例子就是这个。

有任何想法吗?


问题答案:

万一它对任何人都有帮助,我可以通过对我对数据感兴趣的每个字段使用布尔值来解决此问题。然后,我继续追加到StringBuilder,直到到达结束标记,此后,我获取StringBuilder值,然后将其清空,并将布尔值设置为false。

@Override
    public void startElement(String uri, String localName, String qName, Attributes attrs) throws SAXException {
        sb.delete(0, sb.length());
        if (localName.equalsIgnoreCase("channel")) {
            inChannel = true;
            newFeed = new Feed();
            itemList = new ArrayList<Item>();
        }
        if (inChannel) {            
            if (localName.equalsIgnoreCase("image")) {
                feedImage = new Image();
                inImage = true;
                return;
            }           
            else if (localName.equalsIgnoreCase("item")) {
                newItem = new Item();
                inItem = true;
                return;
            }

            if(inImage) { //set booleans for image elements
                if (localName.equalsIgnoreCase("title")) imgTitle = true;
                else if (localName.equalsIgnoreCase("link")) imgLink = true;
                else if (localName.equalsIgnoreCase("url")) imgURL = true;
                return;
            }           
            else if(inItem) { //set booleans for item elements
                if (localName.equalsIgnoreCase("title")) iTitle = true;
                else if (localName.equalsIgnoreCase("link")) iLink = true;
                else if (localName.equalsIgnoreCase("description")) iDescription = true;
                else if (localName.equalsIgnoreCase("author")) iAuthor = true;
                else if (localName.equalsIgnoreCase("category")) iCategory = true;
                else if (localName.equalsIgnoreCase("comments")) iComments = true;
                else if (localName.equalsIgnoreCase("guid")) iGuid = true;
                else if (localName.equalsIgnoreCase("pubdate")) iPubDate= true;
                else if (localName.equalsIgnoreCase("source")) iSource = true;
                return;
            } else { //set booleans for channel elements
                if (localName.equalsIgnoreCase("title")) fTitle = true;
                else if (localName.equalsIgnoreCase("link")) fLink = true;
                else if (localName.equalsIgnoreCase("description")) fDescription = true;
                else if (localName.equalsIgnoreCase("language")) fLanguage= true;
                else if (localName.equalsIgnoreCase("copyright")) fCopyright = true;
                else if (localName.equalsIgnoreCase("category")) fCategory = true;
                return;
            }
        }       
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        if(inChannel) {
            if(inImage) {
                if (localName.equalsIgnoreCase("title")) {
                    feedImage.setTitle(sb.toString());
                    sb.delete(0, sb.length());
                    imgTitle = false;
                    return;
                }
                else if (localName.equalsIgnoreCase("link")) {
                    feedImage.setLink(sb.toString());
                    sb.delete(0, sb.length());
                    imgLink = false;
                    return;
                }
                else if (localName.equalsIgnoreCase("url")) {
                    feedImage.setUrl(sb.toString());
                    sb.delete(0, sb.length());
                    imgURL = false;
                    return;
                }
                else return;
            } 
            else if(inItem) {
                if (localName.equalsIgnoreCase("item")) {
                    itemList.add(newItem);
                    newItem = null;
                    inItem = false;
                    return;
                } else if (localName.equalsIgnoreCase("title")) {
                    newItem.setTitle(sb.toString()); 
                    sb.delete(0, sb.length());
                    iTitle = false;
                    return;
                } else if (localName.equalsIgnoreCase("link")) {
                    newItem.setLink(sb.toString()); 
                    sb.delete(0, sb.length());
                    iLink = false;
                    return;
                } else if (localName.equalsIgnoreCase("description")) {
                    newItem.setDescription(sb.toString()); 
                    sb.delete(0, sb.length());
                    iDescription = false;
                    return;
                } else if (localName.equalsIgnoreCase("author")) {
                    newItem.setAuthor(sb.toString()); 
                    sb.delete(0, sb.length());
                    iAuthor = false;
                    return;
                } else if (localName.equalsIgnoreCase("category")) {
                    newItem.addCategory(sb.toString()); 
                    sb.delete(0, sb.length());
                    iCategory = false;
                    return;
                } else if (localName.equalsIgnoreCase("comments")) {
                    newItem.setComments(sb.toString());
                    sb.delete(0, sb.length());
                    iComments = false;
                    return;
                } /*else if (localName.equalsIgnoreCase("enclosure")) {
                     To be implemented later
                }*/ else if (localName.equalsIgnoreCase("guid")) {
                    newItem.setGuid(sb.toString()); 
                    sb.delete(0, sb.length());
                    iGuid = false;
                    return;
                } else if (localName.equalsIgnoreCase("pubDate")) {
                    newItem.setPubDate(sb.toString()); 
                    sb.delete(0, sb.length());
                    iPubDate = false;
                    return;
                }
            } 
            else {
                if(localName.equalsIgnoreCase("channel")) {
                    newFeed.setItems((ArrayList<Item>)itemList);
                    finalFeed = newFeed;
                    newFeed = null;                     
                    inChannel = false;
                    return;
                } else if(localName.equalsIgnoreCase("title")) {
                    newFeed.setTitle(currentValue); 
                    sb.delete(0, sb.length());
                    fTitle = false;
                    return;
                } else if(localName.equalsIgnoreCase("link")) {
                    newFeed.setLink(currentValue); 
                    sb.delete(0, sb.length());
                    fLink = false;
                    return;
                } else if(localName.equalsIgnoreCase("description")) {
                    newFeed.setDescription(sb.toString());
                    sb.delete(0, sb.length());
                    fDescription = false;
                    return;
                } else if(localName.equalsIgnoreCase("language")) {
                    newFeed.setLanguage(currentValue); 
                    sb.delete(0, sb.length());
                    fLanguage = false;
                    return;
                } else if(localName.equalsIgnoreCase("copyright")) {
                    newFeed.setCopyright(currentValue); 
                    sb.delete(0, sb.length());
                    fCopyright = false;
                    return;
                } else if(localName.equalsIgnoreCase("category")) {
                    newFeed.addCategory(currentValue); 
                    sb.delete(0, sb.length());
                    fCategory = false;
                    return;
                }
            }
        }
    }

    @Override
    public void characters(char[] ch, int start, int length) {
        sb.append(new String(ch, start, length));
    }


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