在SSM框架中，multfile轉file

import org.apache.commons.fileupload.disk.DiskFileItem;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import java.io.File;
import java.io.IOException;

public class MultipartToFile {
    /**
     * multfile轉file
     * @param multfile
     * @return
     * @throws IOException
     */
    public static File multipartToFile(MultipartFile multfile) throws IOException {
        CommonsMultipartFile cf = (CommonsMultipartFile)multfile;
        //這個myfile是MultipartFile的
        DiskFileItem fi = (DiskFileItem) cf.getFileItem();
        File file = fi.getStoreLocation();
        //手動建立臨時檔案
        if(file.length() < 2048){//如果檔案小於2M，建立臨時檔案
            File tmpFile = new File(System.getProperty("java.io.tmpdir") + System.getProperty("file.separator") +
                    file.getName());
            multfile.transferTo(tmpFile);
            return tmpFile;
        }
        return file;
    }

    /**
     * 獲取檔名稱，除去字尾名
     * @param filename
     * @return
     */
    public static String getFileNameNoEx(String filename) {
        if ((filename != null) && (filename.length() > 0)) {
            int dot = filename.lastIndexOf('.');
            if ((dot >-1) && (dot < (filename.length()))) {
                return filename.substring(0, dot);
            }
        }
        return filename;
    }
}