Java 中HttpURLConnection附件上传的实例详解
发布时间:2020-12-14 14:10:08 所属栏目:Java 来源:网络整理
导读:Java 中HttpURLConnection附件上传的实例详解 整合了一个自己写的采用Http做附件上传的工具,分享一下! 示例代码: /** * 以Http协议传输文件 * * @author mingxue.zhang@163.com * */ public class HttpPostUtil { private final static char[] MULTIPART_
Java 中HttpURLConnection附件上传的实例详解 整合了一个自己写的采用Http做附件上传的工具,分享一下! 示例代码: /** * 以Http协议传输文件 * * @author mingxue.zhang@163.com * */ public class HttpPostUtil { private final static char[] MULTIPART_CHARS = "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" .toCharArray(); private URL url; private HttpURLConnection conn; private String boundary = null; private Map<String,String> textParams = new HashMap<String,String>(); private Map<String,File> fileparams = new HashMap<String,File>(); public HttpPostUtil(String url) throws Exception { this.url = new URL(url); } // 重新设置要请求的服务器地址,即上传文件的地址。 public void setUrl(String url) throws Exception { this.url = new URL(url); } // 增加一个普通字符串数据到form表单数据中 public void addTextParameter(String name,String value) { textParams.put(name,value); } // 增加一个文件到form表单数据中 public void addFileParameter(String name,File value) { fileparams.put(name,value); } // 清空所有已添加的form表单数据 public void clearAllParameters() { textParams.clear(); fileparams.clear(); } /** * 发送数据到服务器 * * @return 一个字节包含服务器的返回结果的数组 * @throws Exception */ public byte[] send() throws Exception { initConnection(); try { conn.connect(); } catch (SocketTimeoutException e) { throw new Exception(e); } OutputStream connOutStream = new DataOutputStream( conn.getOutputStream()); writeFileParams(connOutStream); writeStringParams(connOutStream); writesEnd(connOutStream); InputStream responseInStream = conn.getInputStream(); ByteArrayOutputStream responSEOutStream = new ByteArrayOutputStream(); int len; byte[] bufferByte = new byte[1024]; while ((len = responseInStream.read(bufferByte)) != -1) { responSEOutStream.write(bufferByte,len); } responseInStream.close(); connOutStream.close(); conn.disconnect(); byte[] resultByte = responSEOutStream.toByteArray(); responSEOutStream.close(); return resultByte; } // 文件上传的connection的一些必须设置 private void initConnection() throws Exception { StringBuffer buf = new StringBuffer("----"); Random rand = new Random(); for (int i = 0; i < 15; i++) { buf.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]); } this.boundary = buf.toString(); conn = (HttpURLConnection) this.url.openConnection(); conn.setDoOutput(true); conn.setUseCaches(false); conn.setConnectTimeout(3 * 60 * 1000); // 连接超时为10秒 conn.setRequestMethod("POST"); conn.setRequestProperty("Content-Type","multipart/form-data; boundary=" + boundary); } // 普通字符串数据 private void writeStringParams(OutputStream out) throws Exception { Set<String> keySet = textParams.keySet(); for (Iterator<String> it = keySet.iterator(); it.hasNext();) { String name = it.next(); String value = textParams.get(name); out.write(("--" + boundary + "rn").getBytes()); out.write(("Content-Disposition: form-data; name="" + name + ""rn") .getBytes()); out.write(("rn").getBytes()); out.write((encode(value) + "rn").getBytes()); } } // 文件数据 private void writeFileParams(OutputStream out) throws Exception { Set<String> keySet = fileparams.keySet(); for (Iterator<String> it = keySet.iterator(); it.hasNext();) { String name = it.next(); File value = fileparams.get(name); out.write(("--" + boundary + "rn").getBytes()); out.write(("Content-Disposition: form-data; name="" + name + ""; filename="" + encode(value.getName()) + ""rn") .getBytes()); out.write(("Content-Type: " + getContentType(value) + "rn") .getBytes()); out.write(("Content-Transfer-Encoding: " + "binary" + "rn") .getBytes()); out.write(("rn").getBytes()); FileInputStream inStream = new FileInputStream(value); int bytes = 0; byte[] bufferByte = new byte[1024]; while ((bytes = inStream.read(bufferByte)) != -1) { out.write(bufferByte,bytes); } inStream.close(); out.write(("rn").getBytes()); } } // 添加结尾数据 private void writesEnd(OutputStream out) throws Exception { out.write(("--" + boundary + "--" + "rn").getBytes()); out.write(("rn").getBytes()); } // 获取文件的上传类型,图片格式为image/png,image/jpg等。非图片为application/octet-stream private String getContentType(File f) throws Exception { String fileName = f.getName(); if (fileName.endsWith(".jpg")) { return "image/jpeg"; } else if (fileName.endsWith(".png")) { return "image/png"; } return "application/octet-stream"; } // 对包含中文的字符串进行转码,此为UTF-8。服务器那边要进行一次解码 private String encode(String value) throws Exception { return URLEncoder.encode(value,"UTF-8"); } } 如有疑问请留言或者到本站社区交流讨论,感谢阅读,希望能帮助到大家,谢谢大家对本站的支持! (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |