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  • HttpServletResponse实现文件下载

    import java.io.BufferedInputStream;
    import java.io.BufferedOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.URLEncoder;
    import javax.servlet.http.HttpServletResponse;
    import org.springframework.util.StringUtils;
    
    /**
     * 文件下载
     */
    public class FileLoad {
    
        /**
         * 使用response返回文件流
         */
        public void loadFile(String filePath, HttpServletResponse response) {
            // 声明工具类
            BufferedInputStream in = null;
            BufferedOutputStream out = null;
    
            try {
                // 若路径为空
                if (StringUtils.isEmpty(filePath)) {
                    throw new Exception("invalid filepath of null.");
                }
    
                // 没找到文件
                File file = new File(filePath);
                if (!file.exists()) {
                    throw new Exception("file not exist in path [" + filePath + "]");
                }
    
                // 获取文件名
                String fileName = file.getName();
    
                // 输出文件流到浏览器
                in = new BufferedInputStream(new FileInputStream(filePath));
                out = new BufferedOutputStream(response.getOutputStream());
                response.setContentType("application/x-download;charset=utf-8");
                response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
    
                byte[] buffer = new byte[8192];
                int count = 0;
                while ((count = in.read(buffer, 0, 8192)) != -1) {
                    out.write(buffer, 0, count);
                }
    
                out.flush();
                file = null;
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                closeStream(in, out);
            }
        }
    
        /**
         * 关闭输入输出流
         */
        public void closeStream(InputStream in, OutputStream out) {
            if (null != in) {
                try {
                    in.close();
                } catch (IOException e) {
                    // e.printStackTrace();
                }
            }
            if (null != out) {
                try {
                    out.close();
                } catch (IOException e) {
                    // e.printStackTrace();
                }
            }
        }
    
    }
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  • 原文地址:https://www.cnblogs.com/zj0208/p/8436539.html
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