svg文件转标签形式（字符串）。MultipartFile转File

对于svg矢量图的处理，一般可能是存文件形式，但如果只是很少量的，也可直接存数据库：
利用batik既可：

		
            org.apache.xmlgraphics
            batik-all
            1.14
            pom
        

import org.apache.batik.anim.dom.SAXSVGdocumentFactory;
import org.apache.batik.util.XMLResourceDescriptor;
import org.w3c.dom.document;
import org.w3c.dom.Element;

import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.File;
import java.io.IOException;
import java.io.StringWriter;
public class SvgUtil {
    
    public static String analysisOfSVG(File file) throws IOException {
        String parser = XMLResourceDescriptor.getXMLParserClassName();
        SAXSVGdocumentFactory f = new SAXSVGdocumentFactory(parser);
        document doc = f.createdocument(file.toURI().toString());
		//这里直接获取全部，也可以获取部分
        Element element = doc.getdocumentElement();
        return transformationSVG(element);
    }

    
    public static String transformationSVG(Element element) {
        TransformerFactory transFactory = TransformerFactory.newInstance();
        Transformer transformer = null;
        try {
            transformer = transFactory.newTransformer();
        } catch (TransformerConfigurationException e) {
            e.printStackTrace();
        }
        StringWriter buffer = new StringWriter();
        assert transformer != null;
        transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        try {
            transformer.transform(new DOMSource(element), new StreamResult(buffer));
        } catch (TransformerException e) {
            e.printStackTrace();
        }
        return buffer.toString();
    }
}

doc.getdocumentElement();这里是直接获取了整个所有标签，获取出来大概是这样：（也可以根据名称或者id获取其中某个标签的内容）

当然前后端交互文件一般是MultipartFile。直接转File一下（记得删除临时文件deleteTempFile）：

import org.springframework.web.multipart.MultipartFile;

import java.io.*;
import java.nio.file.Files;
import java.util.Objects;

public class MultipartFileUtil {
    
    public static File multipartFileToFile(MultipartFile file) {
        File toFile = null;
        try (InputStream ins = file.getInputStream()) {
            toFile = new File(Objects.requireNonNull(file.getOriginalFilename()));
            inputStreamToFile(ins, toFile);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return toFile;
    }

    
    private static void inputStreamToFile(InputStream ins, File file) {
        try (OutputStream os = new FileOutputStream(file)) {
            int bytesRead = 0;
            byte[] buffer = new byte[8192];
            while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            ins.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    
    public static void deleteTempFile(File file) throws IOException {
        Files.delete(file.toPath());
    }