注意：如果直接使用uri的连接将图片上传到fastdfs会导致图片上传不完整，所以需要将图片先保存下来，上传完成后再删除

Imagedownload

public static String fastdfsdownload(String imgUrl) {
        String filepath = "";
        File file = null;
        try {
            // 获取图片URL
            URL url = new URL(imgUrl);
            // 获得连接
            URLConnection connection = url.openConnection();
            // 设置10秒的相应时间
            connection.setConnectTimeout(10 * 1000);
            
            //模拟浏览器访问，防止网站屏蔽
            connection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.19 Safari/537.36");
            
            InputStream is = connection.getInputStream();
            if (is == null || is.available() <= 0) {
                return null;
            }
            //得到临时文件
            file = getTemplateFile(is);
            
            filepath = fastDFS.upload(file);
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return filepath;
    }

public static File getTemplateFile(InputStream inputStream) {
        File file = null;
        try {
            file = File.createTempFile("temp_image", null);
        } catch (IOException e) {
            e.printStackTrace();
        }
        inputStreamToFile(inputStream, file);
        if (file.exists() && file.length() <= 0) {
            return null;
        }
        return file;
    }

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

FastDFS

package com.neusoft.util;

import com.neusoft.fastdfsTemlate.FastDFSTemplate;
import com.neusoft.fastdfsTemlate.FastDfsInfo;
import com.neusoft.fastdfsTemlate.exception.FastDFSException;
import org.csource.common.NameValuePair;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.*;
import java.util.HashMap;
import java.util.Map;

public class FastDFS {
    private BeanFactory beanFactory = new ClassPathXmlApplicationContext("classpath:spring-fastdfs.xml");
    private FastDFSTemplate dfsTemplate = (FastDFSTemplate) beanFactory.getBean("fastDFSTemplate");

    public String upload(File tempFile) {
        InputStream is = null;
        try {
            is = new FileInputStream(tempFile);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        byte[] bytes = null;
        try {
            bytes = new byte[is.available()];
            int length = is.read(bytes);
        } catch (IOException e) {
            e.printStackTrace();
        }
        Map<String, String> map = new HashMap<>();
        FastDfsInfo rv = null;
        try {
            rv = dfsTemplate.upload(bytes, "jpg", map);
        } catch (FastDFSException e) {
            e.printStackTrace();
        }finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (tempFile != null) {
                tempFile.delete();
            }
        }
        assert rv != null;
        return rv.getFileAbsolutePath();
    }
}