小编典典

Java中具有参数的高效XSLT管道

java

这个问题的最高答案描述了一种在Java中实现有效的XSLT管道的技术:

[Java中有效的XSLT管道(或将结果重定向到源)http://codingdict.com/questions/155853

不幸的是,尽管Transformer似乎公开了用于设置XSLT参数的API,但这似乎没有任何效果。例如,我有以下代码:

变形金刚

import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.Templates;
import javax.xml.transform.sax.TransformerHandler; 
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.Transformer;
import java.io.File;
public class MyTransformer {
    public static void main(String[] args) throws javax.xml.transform.TransformerConfigurationException, javax.xml.transform.TransformerException{
        SAXTransformerFactory stf = (SAXTransformerFactory)TransformerFactory.newInstance();

        // These templates objects could be reused and obtained from elsewhere.
        Templates templates1 = stf.newTemplates(new StreamSource( new File("MyStylesheet1.xslt")));
        Templates templates2 = stf.newTemplates(new StreamSource(new File("MyStylesheet2.xslt")));

        TransformerHandler th1 = stf.newTransformerHandler(templates1);
        TransformerHandler th2 = stf.newTransformerHandler(templates2);

        th1.setResult(new SAXResult(th2));
        th2.setResult(new StreamResult(System.out));

        Transformer t = stf.newTransformer();

            //SETTING PARAMETERS HERE
        t.setParameter("foo","this is from param 1");
        t.setParameter("bar","this is from param 2");

        t.transform(new StreamSource(new File("in.xml")), new SAXResult(th1));

        // th1 feeds th2, which in turn feeds System.out.
    }
}

MyStylesheet1.xslt

<?xml version="1.0"?>
<stylesheet xmlns="http://www.w3.org/1999/XSL/Transform"  xmlns:foo="urn:foo" version="1.0">
    <output method="xml"/>

    <param name="foo"/>

    <template match="@*|node()">
        <copy>
            <apply-templates select="@*|node()"/>
        </copy>
    </template>

    <template match="foo:my/foo:hello">
        <copy>
            <foo:world>
                foo is : <value-of select="$foo"/>
            </foo:world>
        </copy>

    </template>
</stylesheet>

MyStylesheet2.xslt

<?xml version="1.0"?>
<stylesheet xmlns="http://www.w3.org/1999/XSL/Transform" xmlns:foo="urn:foo" version="1.0">
    <output method="xml"/>

    <param name="bar"/>

    <template match="@*|node()">
        <copy>
            <apply-templates select="@*|node()"/>
        </copy>
    </template>

    <template match="foo:my/foo:hello/foo:world">
        <copy>
            <apply-templates select="@*|node()"/>

            <attribute name="attr">
                <value-of select="$bar"/>
            </attribute>
        </copy>

    </template>
</stylesheet>

in.xml

<my xmlns="urn:foo">
    <hello/>
</my>

这给了我以下输出:

<?xml version="1.0" encoding="UTF-8"?><my xmlns="urn:foo">
        <hello><foo:world xmlns:foo="urn:foo">foo is : </foo:world></hello>
</my>

如您所见,foo:world / @ attr为空,并且foo:world的文本内容为“ foo
is:”。预期的行为是应该使用传递给setParameter方法的参数填充它们。

有没有一种方法可以使用此技术设置XSL转换参数。如果不是,那么谁能推荐一种替代方法来在Java中有效地转换样式表,从而也可以设置XSLT参数?


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2020-11-26

共1个答案

小编典典

问题在于每个TransformerHandler都有一个与之关联的单独的Transformer。您的第二个模板有问题,但是由于这是一个示例,我想这没关系。你要:

//SETTING PARAMETERS HERE
th1.getTransformer().setParameter("foo","this is from param 1");
th2.getTransformer().setParameter("bar","this is from param 2");

请注意,您也不需要创建第三个转换器,只需在th1.getTransformer()上启动转换链即可。

2020-11-26