ftp读取图片返回json字符串前端显示

最新推荐文章于 2021-08-05 08:14:34 发布

码农郑在漂

最新推荐文章于 2021-08-05 08:14:34 发布

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分类专栏： ftp 文章标签：图片base64返回json数据

本文链接：https://blog.youkuaiyun.com/qq_37219629/article/details/103227616

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后端通过FTP下载图片并转换为Base64编码，然后将编码封装成JSON字符串返回给前端。前端接收到数据后解析JSON，创建Image对象并设置源为Base64字符串，实现在页面上显示图片。

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后端

@GetMapping("/downloadPic")
@ResponseBody
public Result downloadPic(@RequestParam(“path”) String path, HttpServletResponse response) throws Exception {
String host = “116.255.145.237”;
int port = 21;
String username = “ftpuser”;
String password = “yw_ftp123”;
FTPClient ftp = new FTPClient();
String remotePath = path.substring(0, path.lastIndexOf("/"));
String fileName = path.substring(path.lastIndexOf("/")+1);
String stringData = “”;
try {
int reply;
ftp.connect(host, port);
// 如果采用默认端口，可以使用ftp.connect(host)的方式直接连接FTP服务器
// 登录
ftp.login(username, password);
reply = ftp.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) {
ftp.disconnect();
}
ftp.enterLocalPassiveMode();
// 转移到FTP服务器目录
ftp.changeWorkingDirectory(remotePath);
InputStream in = ftp.retrieveFileStream(fileName);
ByteArrayOutputStream sos = new ByteArrayOutputStream();
int len = 0;
byte[] buffer = new byte[1024];
while ((len = in.read(buffer)) > 0) {
sos.write(buffer, 0, len);
}
byte[] bytes = sos.toByteArray();
BASE64Encoder encoder = new BASE64Encoder();
stringData = “data:image/jpeg;base64,” + encoder.encode(bytes);
in.close();
sos.close();
ftp.logout();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (ftp.isConnected()) {
try {
ftp.disconnect();
} catch (IOException ioe) {
}
}
}
Result result = new Result();
result.setResult(stringData);
return result;
}

前端

$(function(){
$.ajax({
url: “http://localhost:8191/ywedu/upload/downloadPic?path=/lcs/images/2019/11/14/17/file_47420f2050094de482757f1ff4b394ed_1573724674665.jpeg”,
type: “GET”,
success: function (data) {
console.log(data)
var img = new Image();
img.src = data;
img.width = 100;
img.height = 100;
$("#img").append(img)
},
error: function() {console.log(‘fail’);}
});
})