使用Apache POI提取WMF文件数据，将其转换为Java2D图像，然后使用Batik将Java2D图像转换为SVG格式。示例代码如下：

import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileInputStream;
import org.apache.poi.hwmf.record.HwmfRecord;
import org.apache.poi.hwmf.record.HwmfRecordType;
import org.apache.poi.hwmf.usermodel.HwmfPicture;
import org.apache.poi.hwmf.usermodel.HwmfShapeRenderer;
import org.apache.poi.hwmf.usermodel.HwmfTrapezoid;
import org.apache.poi.hwmf.usermodel.HwmfWindowing;

public class WMFConverter {

    public static void convert(String inputFilePath, String outputFilePath)
            throws Exception {

        FileInputStream fis = new FileInputStream(inputFilePath);
        HwmfPicture picture = new HwmfPicture(fis,
                HwmfWindowing.SCALE_PAGE, false);

        Dimension dim = picture.getSize();
        BufferedImage image = new BufferedImage(dim.width, dim.height,
                BufferedImage.TYPE_INT_ARGB);
        Graphics2D g2d = image.createGraphics();
        HwmfShapeRenderer renderer = new HwmfShapeRenderer(g2d);
        for (HwmfRecord record : picture.getRecords()) {
            if (record.getRecordType() == HwmfRecordType.polygon) {
                HwmfTrapezoid trapezoid = new HwmfTrapezoid();
                trapezoid.init(record.getWMFRecord().getData());
                renderer.drawPolygon(trapezoid.xPoints, trapezoid.yPoints,
                        trapezoid.nPoints);
            }
        }
        g2d.dispose();

        SVGGraphics2D svg = new SVGGraphics2D(dim.width, dim.height);
        svg.drawImage(image, 0, 0, null);
        OutputStreamWriter outWriter = new OutputStreamWriter(
                new FileOutputStream(outputFilePath), "UTF-8");
        svg.stream(outWriter, true /* use css */, true /* escape text */);
    }
}

要使用该方法，只需调用WMFConverter.convert(inputFilePath, outputFilePath)并提供输入和输出文件路径即可。