1- html、jsp 设置a标签属性。我这里就不说了.....（<a href="imges/1.jpg" download="图片"><img src="imges/1.jpgf" alt="图片"></a>）

2- PHP

<? 
$file_name = "xxx.rar";     //下载文件名  
$file_dir = "./up/";        //下载文件存放目录  
//检查文件是否存在  
if (! file_exists ( $file_dir . $file_name )) {  
    echo "文件找不到";  
    exit ();  
} else {  
    //打开文件  
    $file = fopen ( $file_dir . $file_name, "r" );  
    //输入文件标签   
    Header ( "Content-type: application/octet-stream" );  
    Header ( "Accept-Ranges: bytes" );  
    Header ( "Accept-Length: " . filesize ( $file_dir . $file_name ) );  
    Header ( "Content-Disposition: attachment; filename=" . $file_name );  
    //输出文件内容   
    //读取文件内容并直接输出到浏览器  
    echo fread ( $file, filesize ( $file_dir . $file_name ) );  
    fclose ( $file );  
    exit ();  
}  
?> 

。。。。。。。。。。。。。。。。。

算了，其他的就不说了。。

JAVA --- 生成的链接直接下载

    @RequestMapping(value = "download/pdf", method = RequestMethod.GET)
    public void creditFailurePdf(HttpServletRequest request, HttpServletResponse response) 
    {
        String code = CommUtil.toString(request.getParameter("code"));
        creditFailurePdfService.getPdf(code, response);
    }

 CommUtil.toString 是转String 的方法

  getPdf()方法如下：这里in为输入流

InputStream in = getFileStream(pdfUrl);

public InputStream getFileStream(String filePath){
        String DEFAULT_ENCODING = "UTF-8";
        BufferedReader reader = null;
        StringBuilder sb = new StringBuilder();
        URL url;
        InputStream in = null;
        try {
            url = new URL(CommUtil.toString(filePath));
            URLConnection conn;
            try {
                conn = url.openConnection();
                conn.setDoOutput(true);
                conn.setConnectTimeout(120000);
                conn.connect();
                in = conn.getInputStream();
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return in;
    }

public void getPdf(String code, HttpServletResponse response){
        BufferedOutputStream bost = null;
        BufferedInputStream inbuf = null;
        ServletOutputStream out = null;
        try {
            out = response.getOutputStream();
            bost = new BufferedOutputStream(out);
            // 设置response参数，打开下载页面
            response.reset();
            response.setContentType("APPLICATION/octet-stream");
            response.setContentType("text/html;CHARSET=UTF-8");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode((CommUtil.getUUID() + ".pdf"), "UTF-8"));
            // 生成下载文件
            // 每次读取1024字节的数据并写入到文件中
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int len;
            try {
                while ((len = in.read(buffer)) > -1) {
                    baos.write(buffer, 0, len);
                }
                baos.flush();
            } catch (IOException e) {
                e.printStackTrace();
            }
            in = new ByteArrayInputStream(baos.toByteArray());
            inbuf = new BufferedInputStream(in);
            byte[] by = new byte[1024];
            while (true) {
                len = inbuf.read(by);
                if (len == -1) {
                    break;
                }
                bost.write(by);
                bost.flush();
            }
            out.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭IO
            try {
                if (out != null) {
                    out.close();
                }
                if (bost != null) {
                    bost.close();
                }
                if (inbuf != null) {
                    inbuf.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
}

缘起：

有时点击文本文件的链接的时候，会直接在chrome中打开显示该文本。

解决：

1、右击鼠标，“弹出menu中选择链接另存为”。

结果

昨天做SpringMVC 文件上传下载功能时遇到一堆问题。其中有个问题就是txt css js html xml pdf 等等文件下载时浏览器（html5的a标签download属性不是所有浏览器都支持的）是直接打开,而不是下载保存。网上有许多解决的方法，我这边只是整合下，做个mark。

场景就是有个url，老大提醒说用后台访问url获取文件流 前台来处理。。大概这个流程 代码如下：

前端js部分，参考http://www.alloyteam.com/2014/01/use-js-file-download/

//得到拼接字符串
function getFJInfo(name, url) {
	return "<tr><td style=''><a  href='javascript:void(0)' οnclick='getDownFile(\"" + url + "\",\"" + name + "\")'>" + name + "</a></td></tr>"
}
//文件下载
function getDownFile(url, name) {
	var param = {
		"url": url
	};
	$.ajax({
		url: contextPath + '/product-label/file2Stream',
		type: 'GET',
		data: Base64.encode(JSON.encode(param)),
		dataType: "text",
		success: function(data) {
			downloadFile(name, data)
		}
	})
}
//流处理触发下载事件
function downloadFile(fileName, content) {
	var aLink = document.createElement('a');
	var blob = new Blob([content]);
	var evt = document.createEvent("MouseEvents");
	evt.initMouseEvent("click", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
	aLink.download = fileName;
	aLink.href = URL.createObjectURL(blob);
	aLink.dispatchEvent(evt)
}

后台controller处理，参考http://blog.sina.com.cn/s/blog_87216a0001014sm7.html

/**
     * 返回流
     * 
     * @param requestMap 请求参数
     * @param response 返回对象
     */
    @RequestMapping(value = "/file2Stream", method = RequestMethod.GET)
    public void file2Stream(@Json Map<String, Object> requestMap, HttpServletResponse response) {
        try {
            String url = String.valueOf(requestMap.get("url"));
            // URL url =new URL(String.valueOf(requestMap.get("url")));
            InputStream iStream = getFileStream(url);
            OutputStream stream = response.getOutputStream();
            stream.write(StreamUtils.getBytes(iStream));
            stream.flush();
            stream.close();
        } catch (Exception e) {
            LOG.error("ProductSalesRecommendController.file2Stream  error | ({})", e);
        }
    }

    /**
     * HttpURLConnection获取网络路径的文件流
     * 
     * @param url 链接
     * @return InputStream
     * @throws IOException
     */
    private InputStream getFileStream(URL url) throws IOException {
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setConnectTimeout(5 * 1000);
        conn.setRequestMethod("GET");
        InputStream inStream = conn.getInputStream();
        return inStream;
    }

    /**
     * HttpClient获取网络路径的文件流
     * 
     * @param url 链接字符串
     * @return InputStream
     * @throws IllegalStateException
     * @throws IOException
     */
    private InputStream getFileStream(String url) throws IllegalStateException, IOException {
        HttpParams httpParams = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(httpParams, 5000); // 设置连接超时为5秒
        HttpClient client = new DefaultHttpClient(httpParams); // 生成一个http客户端发送请求对象
        HttpResponse httpResponse = client.execute(new HttpGet(url)); // 发送请求并等待响应
        HttpEntity entity = httpResponse.getEntity(); // 获取响应里面的内容
        InputStream inStream = entity.getContent();
        return inStream;
    }