相关疑难解决方法(0)

我正在使用Java的内置XML转换器来获取DOM文档并打印出生成的XML.问题是尽管明确地设置了参数"indent",但它根本没有缩进文本.

示例代码

public class TestXML {

 public static void main(String args[]) throws Exception {
  ByteArrayOutputStream s;

  Document d = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
  Transformer t = TransformerFactory.newInstance().newTransformer();

  Element a,b;

  a = d.createElement("a");
  b = d.createElement("b");

  a.appendChild(b);

  d.appendChild(a);

  t.setParameter(OutputKeys.INDENT, "yes");

  s = new ByteArrayOutputStream();

  t.transform(new DOMSource(d),new StreamResult(s));

  System.out.println(new String(s.toByteArray()));

 }
}

结果

<?xml version="1.0" encoding="UTF-8" standalone="no"?><a><b/></a>

期望的结果

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<a>
 <b/>
</a>

思考？

使用以下简单代码:

package test;

import java.io.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;

public class TestOutputKeys {
    public static void main(String[] args) throws TransformerException {

        // Instantiate transformer input
        Source xmlInput = new StreamSource(new StringReader(
                "<!-- Document comment --><aaa><bbb/><ccc/></aaa>"));
        StreamResult xmlOutput = new StreamResult(new StringWriter());

        // Configure transformer
        Transformer transformer = TransformerFactory.newInstance()
                .newTransformer(); // An identity transformer
        transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, "testing.dtd");
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        transformer.transform(xmlInput, xmlOutput);

        System.out.println(xmlOutput.getWriter().toString());
    }

}

我得到输出:

<?xml version="1.0" encoding="UTF-8"?>
<!-- Document comment --><!DOCTYPE aaa SYSTEM "testing.dtd">

<aaa>
<bbb/>
<ccc/>
</aaa>

问题A:doctype标签出现在文档注释之后.是否有可能在文件评论之前出现？

问题B:如何仅使用JavaSE 5.0 …

我正在编写一个包含以下代码的XML文件:

Source source = new DOMSource(rootElement);
Result result = new StreamResult(xmlFile);
Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.transform(source, result);

这是输出文件:

<?xml version="1.0" encoding="UTF-8"?>
<feature-sequences>
<sequence>
<initial-frame>0</initial-frame>
<points>
<point>
<x>274.0</x>
<y>316.0</y>
</point>
...

我希望这个文件缩进,例如:

<?xml version="1.0" encoding="UTF-8"?>
<feature-sequences>
  <sequence>
    <initial-frame>0</initial-frame>
    <points>
      <point>
        <x>274.0</x>
        <y>316.0</y>
      </point>
...

setOutputProperty在我的代码中调用并没有解决问题,它实际上使文本用新行(但不缩进).

任何人都有解决方案,而不需要外部库？