通过httpclient上传图片到微信公众号新增临时素材接口

需要的jar包：

	org.apache.httpcomponents
	httpclient
	4.5.6


	org.apache.httpcomponents
	httpmime
	4.5.6

最简洁的上传文件：

	/**
	 * 通过httpclient测试 微信公众号临时素材上传接口
	 * 
最简洁示例
	 */
	@Test
	public void uploadFileToWxmpMedia() {
		String access_token = "填写你自己的~~";
		URL url = Thread.currentThread().getContextClassLoader().getResource("images/1.jpg");
		File file = new File(url.getFile());
		
		// 组装post请求
		HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/cgi-bin/media/upload?access_token="+access_token+"&type=image");
		
		FileBody fileBody = new FileBody(file);
		HttpEntity reqEntity = MultipartEntityBuilder.create()
				.addPart("media", fileBody)
				.build();
		
		httpPost.setEntity(reqEntity);
		
		try {
			CloseableHttpResponse httpResponse = HttpClients.createDefault().execute(httpPost);
			InputStream content = httpResponse.getEntity().getContent();
			String string = IOUtils.toString(content, "utf-8");
			System.out.println(string);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

运行后，上传成功：

现在将上传的文件改成inputstream，代码如下：

	/**
	 * 通过httpclient测试 微信公众号临时素材上传接口
	 * 
最简洁示例
	 * @throws IOException 
	 */
	@Test
	public void uploadInputStreamToWxmpMedia() throws IOException {
		String access_token = "换成你自己的";
		InputStream inputStream = Thread.currentThread().getContextClassLoader().getResourceAsStream("images/1.jpg");
		
		// 组装post请求
		HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/cgi-bin/media/upload?access_token="+access_token+"&type=image");
		
		InputStreamBody inputStreamBody = new InputStreamBody(inputStream, System.currentTimeMillis()+"_22.jpeg");
		HttpEntity reqEntity = MultipartEntityBuilder.create()
				.addPart("media", inputStreamBody)
				.build();
		
		httpPost.setEntity(reqEntity);
		
		try {
			CloseableHttpResponse httpResponse = HttpClients.createDefault().execute(httpPost);
			InputStream content = httpResponse.getEntity().getContent();
			String string = IOUtils.toString(content, "utf-8");
			System.out.println(string);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

再次进行运行后：

惨了！！报错！~~~

奇怪了，这是为什么？其实本质是同一个文件，怎么就报错了呢？

对比httpclient运行时打印的日志输出：

再看看微信公众号新增临时素材接口说明：

猜测问题很有可能出于此，上传时没有携带文件内容大小的信息（每次开放微信相关产品时，真的好想骂人，文档总是写的不是很清楚，客服也总是联系不上）。

试着将代码改成如下方式：

	/**
	 * 通过httpclient测试 微信公众号临时素材上传接口
	 * 
最简洁示例
	 * @throws IOException 
	 */
	@Test
	public void uploadInputStreamToWxmpMedia() throws IOException {
		String access_token = "换成你自己的~~";
		InputStream inputStream = Thread.currentThread().getContextClassLoader().getResourceAsStream("images/1.jpg");
		
		// 组装post请求
		HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/cgi-bin/media/upload?access_token="+access_token+"&type=image");
		
		ByteArrayBody byteArrayBody = new ByteArrayBody(IOUtils.toByteArray(inputStream), System.currentTimeMillis()+"_22.jpeg");
		HttpEntity reqEntity = MultipartEntityBuilder.create()
				.addPart("media", byteArrayBody)
				.build();
		
		httpPost.setEntity(reqEntity);
		
		try {
			CloseableHttpResponse httpResponse = HttpClients.createDefault().execute(httpPost);
			InputStream content = httpResponse.getEntity().getContent();
			String string = IOUtils.toString(content, "utf-8");
			System.out.println(string);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

运行下看看：

OK了！~~~