java 8 中的漂亮打印 XML [英] Pretty print XML in java 8

问题描述

我有一个存储为 DOM 文档的 XML 文件，我想将它打印到控制台，最好不使用外部库.我知道这个问题在这个网站上被问过多次，但是以前的答案都没有对我有用.我使用的是 java 8，所以这也许是我的代码与以前的问题不同的地方?我还尝试使用从网上找到的代码手动设置转换器，但这只会导致 not found 错误.

I have an XML file stored as a DOM Document and I would like to pretty print it to the console, preferably without using an external library. I am aware that this question has been asked multiple times on this site, however none of the previous answers have worked for me. I am using java 8, so perhaps this is where my code differs from previous questions? I have also tried to set the transformer manually using code found from the web, however this just caused a not found error.

这是我的代码，目前只在控制台左侧的新行上输出每个 xml 元素.

Here is my code which currently just outputs each xml element on a new line to the left of the console.

import java.io.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;


public class Test {
    public Test(){
        try {
            //java.lang.System.setProperty("javax.xml.transform.TransformerFactory", "org.apache.xalan.xsltc.trax.TransformerFactoryImpl");

            DocumentBuilderFactory dbFactory;
            DocumentBuilder dBuilder;
            Document original = null;
            try {
                dbFactory = DocumentBuilderFactory.newInstance();
                dBuilder = dbFactory.newDocumentBuilder();
                original = dBuilder.parse(new InputSource(new InputStreamReader(new FileInputStream("xml Store - Copy.xml"))));
            } catch (SAXException | IOException | ParserConfigurationException e) {
                e.printStackTrace();
            }
            StringWriter stringWriter = new StringWriter();
            StreamResult xmlOutput = new StreamResult(stringWriter);
            TransformerFactory tf = TransformerFactory.newInstance();
            //tf.setAttribute("indent-number", 2);
            Transformer transformer = tf.newTransformer();
            transformer.setOutputProperty(OutputKeys.METHOD, "xml");
            transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
            transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
            transformer.transform(new DOMSource(original), xmlOutput);
            java.lang.System.out.println(xmlOutput.getWriter().toString());
        } catch (Exception ex) {
            throw new RuntimeException("Error converting to String", ex);
        }
    }

    public static void main(String[] args){
        new Test();
    }

}

推荐答案

我猜这个问题与原始文件中的空白文本节点(即只有空格的文本节点)有关.您应该尝试使用以下代码在解析后以编程方式删除它们.如果您不删除它们，Transformer 将保留它们.

I guess that the problem is related to blank text nodes (i.e. text nodes with only whitespaces) in the original file. You should try to programmatically remove them just after the parsing, using the following code. If you don't remove them, the Transformer is going to preserve them.

original.getDocumentElement().normalize();
XPathExpression xpath = XPathFactory.newInstance().newXPath().compile("//text()[normalize-space(.) = '']");
NodeList blankTextNodes = (NodeList) xpath.evaluate(original, XPathConstants.NODESET);

for (int i = 0; i < blankTextNodes.getLength(); i++) {
     blankTextNodes.item(i).getParentNode().removeChild(blankTextNodes.item(i));
}

这篇关于java 8 中的漂亮打印 XML的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！