四种方法生成XML文件

骑猪看日落 2021-05-04 16:06 515阅读 0赞

# 1. DOM #

public class DomTest {
    
        public static void main(String[] args) throws Exception {
            //创建一个DocumentBuilderFactory对象
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            //创建一个DocumentBuilder对象
            DocumentBuilder db = dbf.newDocumentBuilder();
    
            //获取Document对象，代表着要生成的DOM树
            Document document = db.newDocument();
            //根节点添加进DOM树
            Element bookstore = document.createElement("bookstore");
            document.appendChild(bookstore);
            //根节点的子节点，并添加属性
            Element book = document.createElement("book");
            bookstore.appendChild(book);
            book.setAttribute("id","1");//添加属性
            //子节点的子节点，添加文本内容
            Element name = document.createElement("name");
            book.appendChild(name);
            name.setTextContent("鲁宾逊漂流记");
    
            /*DOM树转换成XML文件*/
            //创建TransformerFactory对象，Factory为工厂类，不能直接new对象，通过newInstance获取对象
            TransformerFactory tff = TransformerFactory.newInstance();
            //通过TransformerFactory对象获取Transformer对象
            Transformer tf = tff.newTransformer();
            //设置生成的XML文件自动换行
            tf.setOutputProperty(OutputKeys.INDENT, "yes");
            //生成XML文件
            tf.transform(new DOMSource(document), new StreamResult(new File("book.xml")));
        }
    }

# 2. SAX #

上篇文章中将解析的XML文件内容存到了book类的集合中，所以这里通过集合进行生成XML文件

public class SaxTest {
    
        public static void main(String[] args) throws Exception {
            ArrayList<Book> bookList =  parseXML();
            //1..创建一个SAXTransformerFactory类的对象
            SAXTransformerFactory stff = (SAXTransformerFactory) SAXTransformerFactory.newInstance();
            //2..通过SAXTransformerFactory类的对象创建TransformerHandler类的对象
            TransformerHandler handler = stff.newTransformerHandler();
            //3..过TransformerHandler类的对象创建Transformer类的对象
            Transformer tr = handler.getTransformer();
            //4..通过Transformer类的对象对要生成的XML文件进行设置
            //设置字符编码;是否换行
            tr.setOutputProperty(OutputKeys.ENCODING, "utf-8");
            tr.setOutputProperty(OutputKeys.INDENT, "yes");
            //5..创建result对象
            File f = new File("book.xml");
            if(!f.exists())
                f.createNewFile();
            Result result = new StreamResult(new FileOutputStream(f));
            //6..将handler和result对象相关联
            handler.setResult(result);
            //7..通过handler对象编写XML文件内容
            handler.startDocument();
            AttributesImpl attr = new AttributesImpl();
            handler.startElement(null, null, "bookstore", attr);
            for (Book book : bookList) {
                attr.clear();
                attr.addAttribute(null, null, "id", null, "1");
                handler.startElement(null, null, "book", attr);
                if(book.getName()!=null){
                    handler.startElement(null, null, "name", null);
                    handler.characters(book.getName().toCharArray(), 0, book.getName().toCharArray().length);
                    handler.endElement(null, null, "name");}
                if(book.getAuthor()!=null){
                    handler.startElement(null, null, "author", null);
                    handler.characters(book.getAuthor().toCharArray(), 0, book.getAuthor().toCharArray().length);
                    handler.endElement(null, null, "author");}
                if(book.getYear()!=null){
                    handler.startElement(null, null, "year", null);
                    handler.characters(book.getYear().toCharArray(), 0, book.getYear().toCharArray().length);
                    handler.endElement(null, null, "year");}
                if(String.valueOf(book.getPrice())!=null){
                    handler.startElement(null, null, "price", null);
                    handler.characters(String.valueOf(book.getPrice()).toCharArray(), 0, String.valueOf(book.getPrice()).toCharArray().length);
                    handler.endElement(null, null, "price");}
                if(book.getLanguage()!=null){
                    handler.startElement(null, null, "language", null);
                    handler.characters(book.getLanguage().toCharArray(), 0, book.getLanguage().toCharArray().length);
                    handler.endElement(null, null, "language");}
                handler.endElement(null, null, "book");
            }
            handler.endElement(null, null, "bookstore");
            handler.endDocument();
        }
    }

# 3. DOM4J生成RSS #

RSS（简易信息聚合）是一种基于XML标准，在互联网上被广泛采用的内容包装和投递协议。  
发布一个RSS文件后，这个RSS Feed中包含的信息就能直接被其他站点调用，而且由于这些数据都是标准的XML格式，所以也能在其他的终端和服务中使用，是一种描述和同步网站内容的格式。

public class DOM4JTest {
    
        public static void main(String[] args) throws Exception {
            //1..创建document对象，代表整个XML稳定
            Document document = DocumentHelper.createDocument();
            //2..创建根节点rss
            Element rss = document.addElement("rss");
            //3..添加节点属性
            rss.addAttribute("version", "2.0");
            //4..生成子节点并添加节点内容
            Element channel = rss.addElement("channel");
            Element title = channel.addElement("title");
            title.setText("新闻");
            //5..设置格式（自动换行，缩进）
            OutputFormat format = OutputFormat.createPrettyPrint();
            format.setEncoding("gbk");
            //6..生成XML文件
            XMLWriter writer = new XMLWriter(new FileOutputStream(new File("rss.xml")),format);
            writer.write(document);
        }
    }

# 4. JDOM生成RSS #

public class JDOMTest {
    
        public static void main(String[] args) throws Exception {
            //1..生成根节点,添加属性
            Element rss = new Element("rss");
            rss.setAttribute("version", "2.0");
            //2..生成document对象
            Document document = new Document(rss);
            //3..生成子节点,添加节点内容
            Element channel = new Element("channel");
            rss.addContent(channel);
    
            Element title = new Element("title");
            title.setText("新闻");
            channel.addContent(title);
            //3..设置XML文件格式
            Format format = Format.getPrettyFormat();
            //3..生成XML文件
            XMLOutputter out = new XMLOutputter(format);
            out.output(document, new FileOutputStream("rss.xml"));
        }
    }