java后台图片的上传预览接口 IO流
上传图片接口 图片保存到服务器(适用于任何文件)
/**
* 上传医生照片
* @param request
* @return
* @throws Exception
* @throws IOException
*/
@RequestMapping(value = "uploadfile")
public Object uploadfile(HttpServletRequest request) throws Exception, IOException {
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
String logoPathDir = fileConfig.getPersonImageURL(); //从配置文件中获取服务器保存路径
// 根据真实路径创建目录
File logoSaveFile = new File(logoPathDir);
if (!logoSaveFile.exists()){
logoSaveFile.mkdirs();
}
// 页面控件的文件流
MultipartFile multipartFile = multipartRequest.getFile("file");
// 获取文件的后缀
String suffix = multipartFile.getOriginalFilename().substring(
multipartFile.getOriginalFilename().lastIndexOf("."));
// 使用UUID生成文件名称
String logImageName = UUID.randomUUID().toString() + suffix;// 构建文件名称
// 拼成完整的文件保存路径加文件
String fileName = logoPathDir + logImageName;
File file = new File(fileName);
try {
multipartFile.transferTo(file);
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// 打印出上传到服务器的文件的绝对路径
Map<String, Object> result=new HashMap<String, Object>();
result.put("imgname", logImageName);
result.put("imgnamepath", fileName);
result.put("message", "上传成功");
result.put("statu", 1);
return result;
}
第二种写法 io流
/**
* 上传版本文件
* @param request
* @param response
* @return
* @throws Exception
* @throws IOException
*/
@RequestMapping(value = "uploadfiledemo")
public Object uploadfiledemo(HttpServletRequest request,MultipartHttpServletRequest multiReq,HttpServletResponse response) throws Exception, IOException {
// 获取上传文件的路径
String uploadFilePath = multiReq.getFile("file").getOriginalFilename();
// 截取上传文件的后缀
String uploadFileSuffix = uploadFilePath.substring(
uploadFilePath.lastIndexOf("."));
// 使用UUID生成文件名称
String filename = UUID.randomUUID().toString() + uploadFileSuffix;// 构建文件名称
FileOutputStream fos = null;
FileInputStream fis = null;
try {
fis = (FileInputStream) multiReq.getFile("file").getInputStream();
fos = new FileOutputStream(new File(fileConfig.getAppFileURL() + filename));
byte[] temp = new byte[1024];
int i = fis.read(temp);
while (i != -1) {
fos.write(temp, 0, temp.length);
fos.flush();
i = fis.read(temp);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
// 打印出上传到服务器的文件的绝对路径
Map<String, Object> result=new HashMap<String, Object>();
result.put("appFileName", filename);//文件名称
result.put("appFilePath", fileConfig.getAppFileURL() + filename);//文件带路径的名称
result.put("message", "上传成功");
result.put("statu", 1);
return result;
}
------------------------------------------------------------------------------------------------------------------------------------------
图片预览接口 不需return 将文件流输出即可
/**
* 传入要预览的图片名称
*
* @param path
*/
@RequestMapping(value = "/downloadpicture")
private void downloadPicture(String path, HttpServletResponse response) throws IOException {
//获取文件保存路径
String logoPathDir = fileConfig.getPersonImageURL();
path = logoPathDir + path; //获取服务器上指定的图片路径
InputStream in = null;
ServletOutputStream sos = null;
try {
File file = new File(path);
in = new FileInputStream(file);
sos = response.getOutputStream();
byte[] b = new byte[1024];
while (in.read(b) != -1) {
sos.write(b); //输出
}
sos.flush(); //刷新
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
in.close(); //关闭文件读取流，输出流
sos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
---------------------------------------------------------------------------------------------------------------------------------------
文件下载 保存到本地 需要设置文件头，后缀名等信息 无法使用 文件需要使用FileInputStream
/**
* 传入要下载的app文件的url，将url所对应的文件下载到本地
*
* @param path
*/
@RequestMapping(value = "/downloadappfile")
private void downloadappfile(@RequestParam(value="appFileName",defaultValue="")String path,HttpServletResponse response) throws IOException {
//获取文件保存路径
String logoPathDir = fileConfig.getAppFileURL();
path = logoPathDir + path;
InputStream in = null;
ServletOutputStream sos = null;
try {
File file = new File(path);
response.setCharacterEncoding("utf-8");
//设置Content-Disposition
response.setHeader("Content-Disposition", "attachment;filename="+file.getName());
//设置文件MIME类型
response.setContentType(new MimetypesFileTypeMap().getContentType(file));
in = new FileInputStream(file);
sos = response.getOutputStream();
byte[] b = new byte[1024];
while (in.read(b) != -1) {
sos.write(b);
}
sos.flush();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
in.close();
sos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
第二种写法 使用BufferedInputStream改善读取性能
/**
* 传入要下载的app文件的url，将url所对应的文件下载到本地
* @param path
*/
@RequestMapping(value = "/downloadappfiledemo")
private void downloadappfiledemo(@RequestParam(value="appFileName",defaultValue="")String path,HttpServletResponse response) throws IOException {
//获取文件保存路径
String logoPathDir = fileConfig.getAppFileURL();
path = logoPathDir + path;
response.setHeader("content-type", "application/octet-stream");
response.setContentType("application/octet-stream");
byte[] buff = new byte[1024];
BufferedInputStream bis = null;
OutputStream os = null;
try {
File file = new File(path);
response.setHeader("Content-Disposition", "attachment;filename=" + file.getName());
os = response.getOutputStream();
bis = new BufferedInputStream(new FileInputStream(file));
int i = bis.read(buff);
while (i != -1) {
os.write(buff, 0, buff.length);
os.flush();
i = bis.read(buff);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
InputStream不可以读取文件，它是一个Abstract的类，根本不可能实例化，是所有输入流的基类。而FileInputStream是InputStream的一个实现类，用于读取诸如图像数据之类的原始字节流。
第三种写法
write的flush，是想要不关闭write流的情况下，将已写入缓存的内容发出去。read只是读操作，没有flush。
out不关，是因为out来自socket，socket关了，就不用再关一次out了
/**
* 传入要下载的app文件的url，将url所对应的文件下载到本地
* @param path
*/
@RequestMapping(value = "/downloadappfile")
private Object downloadappfile(@RequestParam(value="appFileName",defaultValue="")String path,HttpServletResponse response) throws IOException {
//获取文件保存路径
String logoPathDir = fileConfig.getAppFileURL();
path = logoPathDir + path;
File file = new File(path);
//如果文件不存在
if(!file.exists()){
return new Response("999999","系统找不到指定文件");
}
response.reset(); // 必要地清除response中的缓存信息
response.setContentType("application/octet-stream; charset=utf-8");
response.setCharacterEncoding("utf-8");
// 设置response的Header
response.setHeader("Content-Disposition", "attachment;filename="+file.getName());
response.addHeader("Content-Length", "" + file.length()); //设置请求头信息写入文件大小
FileInputStream fis = null;
BufferedInputStream bis = null;
try {
fis = new FileInputStream(file);
byte[] buffer = new byte[1024];
bis = new BufferedInputStream(fis);
OutputStream os=response.getOutputStream();
int i = bis.read(buffer);
while (i != -1) {
os.write(buffer, 0, i);
i = bis.read(buffer);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
------------------------------------------------------------------------------------------------------------------
多文件上传
public static String upload(HttpServletRequest request, String DirectoryName) throws IllegalStateException,
IOException {
// 创建一个通用的多部分解析器
CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(request.getSession()
.getServletContext());
// 图片名称
String fileName = null;
// 判断 request 是否有文件上传,即多部分请求
if (multipartResolver.isMultipart(request)) {
// 转换成多部分request
MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request;
// 取得request中的所有文件名
Iterator<String> iter = multiRequest.getFileNames();
while (iter.hasNext()) {
// 记录上传过程起始时的时间，用来计算上传时间
// int pre = (int) System.currentTimeMillis();
// 取得上传文件
MultipartFile file = multiRequest.getFile(iter.next());
if (file != null) {
// 取得当前上传文件的文件名称
String myFileName = file.getOriginalFilename();
// 如果名称不为“”,说明该文件存在，否则说明该文件不存在
if (myFileName.trim() != "") {
// 获得图片的原始名称
String originalFilename = file.getOriginalFilename();
// 获得图片后缀名称,如果后缀不为图片格式，则不上传
String suffix = originalFilename.substring(originalFilename.lastIndexOf(".")).toLowerCase();
if (!fileTypes.contains(suffix)) {
continue;
}
// 获得上传路径的绝对路径地址(/upload)-->
String realPath = request.getSession().getServletContext().getRealPath("/" + DirectoryName);
System.out.println(realPath);
// 如果路径不存在，则创建该路径
File realPathDirectory = new File(realPath);
if (realPathDirectory == null || !realPathDirectory.exists()) {
realPathDirectory.mkdirs();
}
// 重命名上传后的文件名 111112323.jpg
fileName = UUID.randomUUID().toString() + suffix;// 构建文件名称
// 定义上传路径 .../upload/111112323.jpg
File uploadFile = new File(realPathDirectory + "\\" + fileName);
System.out.println(uploadFile);
file.transferTo(uploadFile);
}
}
// 记录上传该文件后的时间
// int finaltime = (int) System.currentTimeMillis();
// System.out.println(finaltime - pre);
}
}
return fileName;
}
------------------------------------------------------------------------------------------------------------------------------------------
