如果解析超大XML文件

最近工作中碰到需要解析超大XML的问题（XML文件超过1G），并且在处理中还碰到无法解析的异常(org.xml.sax.SAXParseException: An invalid XML character (Unicode: 0x19) was found in the element content of the document)。
现在把处理方式和代码分享出来。

try {
           SAXReader saxReader = new SAXReader();
           saxReader.addHandler("/list/XXXX", new ElementHandler() {
                   public void onStart(ElementPath path) {
                                             // do nothing here...
                    }

                    public void onEnd(ElementPath path) {
				 // process a ROW element
				Element row = path.getCurrent();
				Document document = row.getDocument();
				System.out.println(document.asXML());
				row.detach();
                                    }
                               });
            }

            final File file = new File(getFileName(language, isProduct));
            saxReader.setErrorHandler(new ErrorHandler() {
                public void error(SAXParseException e) {
                System.out.println("file:" + file.getName() + "  ERROR: " + e);
                }
                public void fatalError(SAXParseException e) {
                System.out.println("file:" + file.getName() + "  FATAL: " + e);
                }
                public void warning(SAXParseException e) {
                 System.out.println("file:" + file.getName() + "  WARNING: " + e);
                }
            });
            
            InputStreamReader source = new InputStreamReader(new FileInputStream(file));
            saxReader.read(source);
        } catch (DocumentException e) {
            logger.error("error", e);
            return;
        } catch (FileNotFoundException e) {
            logger.error(" error", e);
            return;
        }

如果XML文件中包含了一些不可见的无效字符，就会导致JDom在解析该文件是抛出异常(An invalid XML character Unicode: 0x19 etc)。我们可以通过一些xml工具来保证，如果在xml文件出现了，也可以通过下面这个方法来过滤。

 
public static String stripNonValidXMLCharacters(String in) {
    StringBuffer out = new StringBuffer(); // Used to hold the output.
    char current; // Used to reference the current character.

    if (in == null || ("".equals(in)))
        return ""; // vacancy test.
    for (int i = 0; i < in.length(); i++) {
        current = in.charAt(i); // NOTE: No IndexOutOfBoundsException caught
                                // here; it should not happen.
        if ((current == 0x9) || (current == 0xA) || (current == 0xD)
                || ((current >= 0x20) && (current <= 0xD7FF))
                || ((current >= 0xE000) && (current <= 0xFFFD))
                || ((current >= 0x10000) && (current <= 0x10FFFF)))
            out.append(current);
    }
    return out.toString();
}

转载：http://www.ilehao.com/blog/2012/10/28/parse-big-xml-file/