工具类之文件的下载

package cn.sunline.tiny.flow.owner.center.money;

import cn.sunline.tiny.core.FlowCom;
import cn.sunline.tiny.core.JavaFlow;
import cn.sunline.tiny.core.PriCache;
import cn.sunline.tiny.core.PubCache;
import cn.sunline.tiny.util.Tools;
import cn.sunline.tiny.web.Context;
import cn.sunline.tiny.web.cache.SysConfig;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;

import javax.annotation.Resource;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.UUID;

/**
     * 文件下载
     * @author lin
     */
@Component("download_jsons_flow")
public class download_jsonsFlow extends JavaFlow {
    private static final Logger log = LoggerFactory.getLogger(download_jsonsFlow.class);


    @Autowired
    protected Tools tools;

    @FlowCom(in = "true")
    public String flow_1(Context ct, PriCache pri, PubCache pub){

        JSONObject date = (JSONObject) pri.get("jsonsObj");
//        String fileName = date.getString("fileName");
        String filePath = date.getString("filePath");

        download(filePath,ct.getResponse());
        tools.returnFun("000000", ct);
        return "";
    }

    public HttpServletResponse download(String path, HttpServletResponse response) {
        OutputStream toClient = null;
        try {
            // 要下载的文件的路径。
            File file = new File(path);
            // 文件名。
            String filename = file.getName();
            // 取得文件的后缀名。
            String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
            // 以流的形式下载文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(path));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();
            // 设置response的Header
            response.setContentType("application/octet-stream;charset=UTF-8");
            response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes()));
            response.addHeader("Content-Length", "" + file.length());
            toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }finally {
            IOUtils.closeQuietly(toClient);
        }
        return response;
    }
}