java+MongoDB实现存图片、下载图片
1.存图片
demo:将某个文件存到mongoDB,这个file可以通过前台参数传入,我这里直接将D://test.png存到mongoDB
@RequestMapping("/addFile")
@ResponseBody
public String addFile(){
MongoClient client = new MongoClient("127.0.0.1",27017);
DB db = client.getDB("files");
GridFS fs = new GridFS(db);
try {
GridFSInputFile gridFSInputFile = fs.createFile(new File("D://test.png"));
gridFSInputFile.setFilename("db_test.png");
gridFSInputFile.save();
} catch (IOException e) {
e.printStackTrace();
}
return "file over";
}
执行后,可看到图片已经存入成功:
2.下载图片
需要指定图片id,可从前端参数传入,我这里写死(上一步存图片,对应了一个mongoDB中的files_id):
@RequestMapping("/downFile")
public void downFile(HttpServletResponse response){
String fileId = "5c0f7c374fc404123403d69e";//这里可以通过参数取代
try {
MongoClient client = new MongoClient("127.0.0.1",27017);
DB db = client.getDB("files");
GridFS fs = new GridFS(db);
GridFSDBFile gridFSDBFile = fs.findOne(new ObjectId(fileId));
OutputStream sos = response.getOutputStream();
response.setContentType("application/octet-stream");
// 获取原文件名
String name = (String) gridFSDBFile.get("filename");
String fileName = new String(name.getBytes("GBK"), "ISO8859-1");
// 设置下载文件名
response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
// 向客户端输出文件
gridFSDBFile.writeTo(sos);
sos.flush();
sos.close();
} catch (IOException e) {
e.printStackTrace();
}
}