通过InputStreamResource下载上传图片

1.封装post接口类，需要注意的是Content-Disposition，file和filename根据实际接口进行调整

public static String sendPostFile(String requestUrl,Map<String, String> requestHeader, Map<String, InputStreamResource> fileParams) throws Exception {

HttpURLConnection conn=null;

StringBuilder response=new StringBuilder();

try{

URL realUrl = new URL(requestUrl);

conn = (HttpURLConnection) realUrl.openConnection();

conn.setRequestMethod(“POST”);

conn.setDoOutput(true);

conn.setDoInput(true);

conn.setUseCaches(false);

if (requestHeader != null && requestHeader.size() > 0) {

for (Entry<String, String> entry : requestHeader.entrySet()) {

conn.setRequestProperty(entry.getKey(), entry.getValue());

}

conn.setRequestProperty(“Connection”,“keep-Alive”);

conn.setRequestProperty(“Charset”,“UTF-8”);

conn.setRequestProperty(“Accept-Charset”,“UTF-8”);

String boundary = “--------POST件–文件----------------” + String.valueOf(new Date().getTime());

conn.setRequestProperty(“Content-Type”,“multipart/form-data; charset=UTF-8; boundary=” + boundary);

DataOutputStream dos=new DataOutputStream(conn.getOutputStream());

if(fileParams!=null&&!fileParams.isEmpty()){

for (Entry<String, InputStreamResource> entry : fileParams.entrySet()) {

StringBuilder fileSb=new StringBuilder();

fileSb.append("--").append(boundary).append("\r\n")

.append("Content-Disposition: form-data; name=\"file\"; filename=\"blob\""+"\r\n")

.append("Content-Type: multipart/form-data; charset=UTF-8"+"\r\n")

.append("Content-Transfer-Encoding:8bit"+"\r\n")

.append("\r\n");

dos.write(fileSb.toString().getBytes("UTF-8"));

System.out.println(fileSb.toString());

dos.flush();

InputStream is=entry.getValue().getInputStream();

byte[] buffer=new byte[1024];

int len=0;

while ((len= is.read(buffer))!=-1){

dos.write(buffer,0,len);

}

is.close();

dos.writeBytes("\r\n");

}

String end="--" + boundary + "--\r\n";

dos.write(end.getBytes(StandardCharsets.UTF_8));

dos.flush();

dos.close();

BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));

String line=null;

while ((line=reader.readLine())!=null){

response.append(line);

}

} catch (Exception e) {

e.printStackTrace();

return POST_CATCH;

} finally {

if(conn!=null){

conn.disconnect();

}

return response.toString();

}

2. 接口请求返回的图片直接用InputStream进行接收

public static InputStream sendGetInput(String requestUrl, Map<String, String> requestHeader, String responseEncoding) throws IOException {

String result = "";

BufferedReader reader = null;

InputStream input = null;

// File w2 = null;

try {

if (requestUrl == null || requestUrl.isEmpty()) {

return null;

}

URL realUrl = new URL(requestUrl);

URLConnection connection = realUrl.openConnection();

connection.setRequestProperty(“accept”, “text/html, application/xhtml+xml, image/jxr, /”);

connection.setRequestProperty(“user-agent”, “Mozilla/5.0 (Windows NT 10.0; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0”);

if (requestHeader != null && requestHeader.size() > 0) {

for (Entry<String, String> entry : requestHeader.entrySet()) {

connection.setRequestProperty(entry.getKey(), entry.getValue());

}

connection.connect();

// w2 = new File(“”);

// FileOutputStream fout

// = new FileOutputStream(w2);

input = connection.getInputStream();

// int len = 0;

// byte[] b = new byte[1024];

// while ((len = input.read(b)) != -1) {

// fout.write(b, 0, len);

// }

// fout.flush();

} catch (Exception e) {

} finally {

}

return input;

3.CommonInputStreamResource，将流转换为Resource，上传的时候直接传

org.springframework.core.io.Resource resource = new CommonInputStreamResource(inputStream);

Map fileMap = new HashMap<String, File>();

fileMap.put("file", resource);

public class CommonInputStreamResource extends InputStreamResource {

private int length;

public CommonInputStreamResource(InputStream inputStream) {

super(inputStream);

}

public CommonInputStreamResource(InputStream inputStream, int length) {

super(inputStream);

this.length = length;

}

/**

* 覆写父类方法

* 如果不重写这个方法，并且文件有一定大小，那么服务端会出现异常

* {@code The multi-part request contained parameter data (excluding uploaded files) that exceeded}

* @return

@Override

public String getFilename() {

return "temp";

}

/**

* 覆写父类 contentLength 方法

* 因为 {@link org.springframework.core.io.AbstractResource#contentLength()}方法会重新读取一遍文件，

* 而上传文件时，restTemplate 会通过这个方法获取大小。然后当真正需要读取内容的时候，发现已经读完，会报如下错误。

* <code>

* java.lang.IllegalStateException: InputStream has already been read - do not use InputStreamResource if a stream needs to be read multiple times

* at org.springframework.core.io.InputStreamResource.getInputStream(InputStreamResource.java:96)

* </code>

* <p>

* ref:com.amazonaws.services.s3.model.S3ObjectInputStream#available()

* @return

@Override

public long contentLength() {

int estimate = length;

return estimate == 0 ? 1 : estimate;

}

通过InputStreamResource下载上传图片相关推荐

Android OKHttp3的使用和下载/上传图片
一.OKHttp3简介 OKHttp是一个处理网络请求的轻量级开源框架,由移动支付Square公司贡献,用于替代HttpUriConnection和Apache HTTPClient,进行http请求 ...
Android异步下载网络图片（其一：Handler）
项目中有时候需要获取网络上的图片,并下载下来到手机客户端显示.怎么做呢? 实现思路是: 1:在UI线程中启动一个线程,让这个线程去下载图片. 2:图片完成下载后发送一个消息去通知UI线程 2:UI线程 ...
php将图片导入,php中图片文件的导入，上传与下载
---------------------------------------------图片的导入-------------------------------------------------- ...
基于Hexo和Github搭建博客
文章目录一.前提 1.1 安装hexo 1.2 初始化hexo 1.3 hexo的一些命令 1.4 关于主题 1.4.1 修改主题二.搭建github博客 2.1注册一个域名三.配置ssh ke ...
炸了！3年图片都没了！
一直都是用的 Typora+微博免费图床写作,前段时间突然发现图片全都裂了,打开一看都是 403 . 开始我以为图片微博都给我删了,找了一堆平台去翻我的历史文章看图片是不是都在,找了半天发现图片要么不 ...
destoon7.0火车头免登陆发布接口 destoon模拟人工发布接口 destoon火车头免费采集接口
来源:https://www.destoon.cc/product/view62.html destoon7.0正式版已与2018年4月3日发布,destoon采集专家已与第一时间发布destoon火 ...
一起来聆听亚马逊跨境电商新老麦家的心声
在和朋友闲聊时,用朋友的话说,拥有了智赢,等于拥有了最强大的ERP +海量的产品库.智赢ERP好不好用?一起来聆听亚马逊跨境电商新老麦家的心声! 智赢ERP_跨境电商智赢ERP软件<亚马逊用户心 ...
服务器端集成环信即使通讯
<?php /** -------------------------------------------------- 环信PHP REST示例代码 --------- ...
环信集成服务端封装类-聊天室
环信常用接口封装 <?php class Easemob {private $client_id = '';private $client_secret = "";priva ...

通过InputStreamResource下载上传图片

通过InputStreamResource下载上传图片相关推荐

最新文章

热门文章