问题描述
我正在尝试使用Batik从SVG文档中找到一些元素。
I am trying to find some elements from an SVG document with Batik.
这是我正在使用的示例SVG文档:
This is the example SVG document I am using:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg
xmlns:svg="http://www.w3.org/2000/svg"
xmlns="http://www.w3.org/2000/svg"
version="1.0"
width="400"
height="300"
viewBox="0 -100 400 300"
preserveAspectRatio="none"
id="svg2">
<g id="blubb">
<line x1="0" y1="0" x2="40" y2="120" stroke="red" stroke-width="3"/>
<text class="hurz" x="50" y="150">HURZ!</text>
</g>
</svg>
我正在尝试查找所有文本
元素使用class属性 hurz
。
I am trying to find all text
elements with the class attribute hurz
.
这是一个示例代码:
import java.awt.*;
import java.io.*;
import javax.swing.*;
import org.apache.batik.swing.*;
import org.apache.batik.swing.gvt.*;
import org.w3c.dom.*;
import org.w3c.dom.svg.*;
import org.w3c.dom.xpath.*;
public class XPathTest extends JFrame {
private final JSVGCanvas c= new JSVGCanvas();
public XPathTest(){
this.setLayout(new GridLayout());
this.add(c);
c.setURI(new File("/tmp/bla.svg").toURI().toString());
c.addGVTTreeRendererListener(new GVTTreeRendererAdapter() {
@Override
public void gvtRenderingCompleted(GVTTreeRendererEvent e) {
testXPath();
}
});
}
private void testXPath() {
final SVGDocument document= c.getSVGDocument();
final XPathEvaluator xpathEvaluator= (XPathEvaluator) document;
final SVGElement searchRoot= (SVGElement) document.getElementById("blubb");
//works
final XPathResult result1= (XPathResult) xpathEvaluator.evaluate(".//*[@class=\"hurz\"]", searchRoot, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
printResults(result1);
//doesn't work
final XPathResult result2= (XPathResult) xpathEvaluator.evaluate(".//text[@class=\"hurz\"]", searchRoot, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
printResults(result2);
//doesn't work
final XPathResult result3= (XPathResult) xpathEvaluator.evaluate(".//text", searchRoot, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
printResults(result3);
}
private void printResults(XPathResult result){
int count= 0;
Node node;
while ((node= result.iterateNext()) != null) {
count++;
}
System.out.println(count);
}
public static void main(String[] args){
final XPathTest f= new XPathTest();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(800, 600);
f.setVisible(true);
}
}
运行时,输出为:
1
0
0
显然XPath表达式 .//* [@ class =hurz]
找到正确的节点。但是,当我搜索特定的元素类型(在这种情况下是 text
元素)时,它找不到表达式 .// text [@class =hurz]
和 .// text
。
So obviously the XPath expression .//*[@class="hurz"]
finds the correct nodes. However, when I search for specific element types (in this case text
elements), it finds nothing as with the expressions .//text[@class="hurz"]
and .//text
.
我在做什么错误或者这是Batik中的错误吗?
Am I doing something wrong or is this a bug in Batik?
推荐答案
这是因为默认命名空间 xmlns = http://www.w3.org/2000/svg
。尝试使用 local-name()
函数:
This is because of the default namespace xmlns="http://www.w3.org/2000/svg"
. Try using the local-name()
function:
.//*[local-name()=\"text\" and @class=\"hurz\"]
这篇关于使用Batik从SVG获取具有XPath的特定元素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!