文件上传工具类（JAVA）

最近接手的一个项目需要做一个文件上传的功能，从网上搜到的...，没有自己想要的，emmm,鸡肋，还是自己动手吧

//添加依赖
<!--常用工具包-->
<dependency>
  <groupId>org.apache.commons</groupId>
  <artifactId>commons-lang3</artifactId>
  <version>3.9</version>
</dependency>
<!--加密工具-->
<dependency>
  <groupId>commons-codec</groupId>
  <artifactId>commons-codec</artifactId>
  <version>1.9</version>
</dependency>

添加完依赖开始撸代码吧
献上完整代码↓↓↓

package com.easy.web.utils;

import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.RandomStringUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.time.DateFormatUtils;
import org.apache.velocity.shaded.commons.io.FilenameUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.util.Date;
public class FileUploadUtils {

    /**
     * 设置保存文件路径名
     * @param pathName
     * @return
     */
    public static FileUploadUtils.Builder setPathName(String pathName)
    {
        return builder().setPathName(pathName);
    }
    /**
     * 设置允许上传文件大小
     * @param maxSize
     * @return
     */
    public static FileUploadUtils.Builder setMaxSize(int maxSize)
    {
        return builder().setMaxSize(maxSize);
    }
    /**
     * 设置最大文件名长度
     * @param maxFileNameLength
     * @return
     */
    public static FileUploadUtils.Builder setMaxFileNameLength(int maxFileNameLength)
    {
        return builder().setMaxFileNameLength(maxFileNameLength);
    }

    /**
     * 设置允许上传文件路径
     * @param allowedExtension
     * @return
     */
    public static FileUploadUtils.Builder setAllowedExtension(String[] allowedExtension)
    {
        return builder().setAllowedExtension(allowedExtension);
    }

    public static FileUploadUtils.Builder builder()
    {
        return new Builder();
    }
    public static class Builder{
        /**
         * 默认大小 50M
         */
        private long DEFAULT_MAX_SIZE = 50 * 1024 * 1024;
        /**
         * 默认的文件名最大长度 100
         */
        private int DEFAULT_FILE_NAME_LENGTH = 100;
        /**
         * 允许上传文件的后缀名
         */
        private String[]DEFAULT_ALLOWED_EXTENSION={};
        /**
         * 保存文件路径名
         */
        private String PATH_NAME;

        public FileUploadUtils.Builder setMaxSize(int maxSize) {
            this.DEFAULT_MAX_SIZE = maxSize*1024*1024;
            return this;
        }

        public FileUploadUtils.Builder setMaxFileNameLength(int maxFileNameLength) {
            this.DEFAULT_FILE_NAME_LENGTH = maxFileNameLength;
            return this;
        }

        public FileUploadUtils.Builder setAllowedExtension(String[] allowedExtension) {
            this.DEFAULT_ALLOWED_EXTENSION = allowedExtension;
            return this;
        }
        public FileUploadUtils.Builder setPathName(String pathName) {
            this.PATH_NAME = pathName;
            return this;
        }
        /**
         * 上传
         * @param file
         * @return
         * @throws IOException
         */
        public final String upload(MultipartFile file) throws IOException {
            //校验
            if (StringUtils.trimToNull(PATH_NAME)==null)throw new IOException("文件保存路径为空");
            String extensionFilename=FilenameUtils.getExtension(file.getOriginalFilename());
            if (!ArrayUtils.isEmpty(DEFAULT_ALLOWED_EXTENSION)&&!ArrayUtils.contains(DEFAULT_ALLOWED_EXTENSION,extensionFilename))throw new IOException("只允许"+ArrayUtils.toString(DEFAULT_ALLOWED_EXTENSION)+"文件上传");
            if (file.getSize()>DEFAULT_MAX_SIZE)throw new IOException("文件过大");
            if (file.getOriginalFilename().length()>DEFAULT_FILE_NAME_LENGTH)throw new IOException("文件名过长");
            //上传
            String fileName = extractFilename(file);
            File desc = getAbsoluteFile(PATH_NAME, fileName);
            file.transferTo(desc);
            return fileName;
        }
        /**
         * 编码文件名
         */
        private final String extractFilename(MultipartFile file)
        {
            String filename = file.getOriginalFilename();
            String extension = getExtension(file);
            filename = DateFormatUtils.format(new Date(),"/yyyy/MM/dd") + "/" + encodingFilename(filename) + "." + extension;
            return filename;
        }
        /**
         * 编码文件名
         */
        private final String encodingFilename(String filename)
        {
            filename = filename.replace("_", " ");
            filename = DigestUtils.md5Hex(filename + System.nanoTime()+ RandomStringUtils.randomNumeric(6));
            return filename;
        }
        /**
         * 获取文件名的后缀
         *
         * @param file 表单文件
         * @return 后缀名
         */
        public final String getExtension(MultipartFile file)
        {
            String extension = FilenameUtils.getExtension(file.getOriginalFilename());
            return extension;
        }

        /**
         * 创建文件
         * @param uploadDir
         * @param filename
         * @return
         * @throws IOException
         */
        private final File getAbsoluteFile(String uploadDir, String filename) throws IOException
        {
            File desc = new File(uploadDir + File.separator + filename);
            if (!desc.getParentFile().exists())
            {
                desc.getParentFile().mkdirs();
            }
            if (!desc.exists())
            {
                desc.createNewFile();
            }
            return desc;
        }
    }
}

把文件放到项目里，使用下面方式调用

//接收 MultipartFile file
//允许上传文件的后缀名
String[]exts={"jpg","gif"};
//将文件上传到d盘下upt文件夹内，只支持后缀名为jpg,gif的文件，文件最大为1M
FileUploadUtils.setPathName("d:/upt/").setAllowedExtension(exts).setMaxSize(1).upload(file);

上传文件轻松搞定！！