java 上传 下载文件工具类

package com.fh.util;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import org.apache.commons.io.FileUtils;
import org.springframework.web.multipart.MultipartFile;

/**

• 说明：上传文件
• 作者：FH Admin
• 官网：fhadmin.cn

*/
public class FileUpload {

/**上传文件
 * @param file             //文件对象
 * @param filePath        //上传路径
 * @param fileName        //文件名
 * @return  文件名
 */
public static String fileUp(MultipartFile file, String filePath, String fileName){
    String extName = ""; // 扩展名格式：
    try {
        if (file.getOriginalFilename().lastIndexOf(".") >= 0){
            extName = file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf("."));
        }
        copyFile(file.getInputStream(), filePath, fileName+extName).replaceAll("-", "");
    } catch (IOException e) {
        System.out.println(e);
    }
    return fileName+extName;
}

/**
 * 写文件到当前目录的upload目录中
 * @param in
 * @param fileName
 * @throws IOException
 */
public static String copyFile(InputStream in, String dir, String realName)
        throws IOException {
    File file = mkdirsmy(dir,realName);
    FileUtils.copyInputStreamToFile(in, file);
    in.close();
    return realName;
}


/**判断路径是否存在，否：创建此路径
 * @param dir  文件路径
 * @param realName  文件名
 * @throws IOException 
 */
public static File mkdirsmy(String dir, String realName) throws IOException{
    File file = new File(dir, realName);
    if (!file.exists()) {
        if (!file.getParentFile().exists()) {
            file.getParentFile().mkdirs();
        }
        file.createNewFile();
    }
    return file;
}


/**下载网络图片上传到服务器上
 * @param httpUrl 图片网络地址
 * @param filePath    图片保存路径
 * @param myFileName  图片文件名(null时用网络图片原名)
 * @return    返回图片名称
 */
public static String getHtmlPicture(String httpUrl, String filePath , String myFileName) {
    
    URL url;                        //定义URL对象url
    BufferedInputStream in;            //定义输入字节缓冲流对象in
    FileOutputStream file;            //定义文件输出流对象file
    try {
        String fileName = null == myFileName?httpUrl.substring(httpUrl.lastIndexOf("/")).replace("/", ""):myFileName; //图片文件名(null时用网络图片原名)
        url = new URL(httpUrl);        //初始化url对象
        in = new BufferedInputStream(url.openStream());                                    //初始化in对象，也就是获得url字节流
        //file = new FileOutputStream(new File(filePath +"\\"+ fileName));
        file = new FileOutputStream(mkdirsmy(filePath,fileName));
        int t;
        while ((t = in.read()) != -1) {
            file.write(t);
        }
        file.close();
        in.close();
        return fileName;
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
    
}

}

package com.fh.util;

import java.io.BufferedOutputStream;
import java.io.OutputStream;
import java.net.URLEncoder;

import javax.servlet.http.HttpServletResponse;

/**

• 说明：下载文件
• 作者：FH Admin
• 官网：fhadmin.cn

*/
public class FileDownload {

/**
 * @param response 
 * @param filePath        //文件完整路径(包括文件名和扩展名)
 * @param fileName        //下载后看到的文件名
 * @return  文件名
 */
public static void fileDownload(final HttpServletResponse response, String filePath, String fileName) throws Exception{  
    byte[] data = FileUtil.toByteArray2(filePath);  
    fileName = URLEncoder.encode(fileName, "UTF-8");  
    response.reset();  
    response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");  
    response.addHeader("Content-Length", "" + data.length);  
    response.setContentType("application/octet-stream;charset=UTF-8");  
    OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());  
    outputStream.write(data);  
    outputStream.flush();  
    outputStream.close();
    response.flushBuffer();
} 

}