Java 发送http请求，上传文件

package wxapi.WxHelper;import java.io.BufferedReader;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.URL;import java.net.URLConnection;import java.util.Date;import java.util.Map;import java.util.Map.Entry;public class HttpRequestUtil {/** * 发送get请求 *  * @param requestUrl *            请求url * @param requestHeader *            请求头 * @param responseEncoding *            响应编码 * @return 页面响应html */public static String sendGet(String requestUrl, Map<String, String> requestHeader, String responseEncoding) {String result = "";BufferedReader reader = null;try {if (requestUrl == null || requestUrl.isEmpty()) {return result;}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();if (responseEncoding == null || responseEncoding.isEmpty()) {responseEncoding = "UTF-8";}reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), responseEncoding));String line;while ((line = reader.readLine()) != null) {result += line;}} catch (Exception e) {System.out.println("发送GET请求出现异常！");e.printStackTrace();} finally {try {if (reader != null) {reader.close();}} catch (Exception e) {e.printStackTrace();}}return result;}/** * 发送post请求 *  * @param requestUrl *            请求url * @param requestHeader *            请求头 * @param formTexts *            表单数据 * @param files *            上传文件 * @param requestEncoding *            请求编码 * @param responseEncoding *            响应编码 * @return 页面响应html */public static String sendPost(String requestUrl, Map<String, String> requestHeader, Map<String, String> formTexts, Map<String, String> files, String requestEncoding, String responseEncoding) {OutputStream out = null;BufferedReader reader = null;String result = "";try {if (requestUrl == null || requestUrl.isEmpty()) {return result;}URL realUrl = new URL(requestUrl);HttpURLConnection connection = (HttpURLConnection) 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.setDoOutput(true);connection.setDoInput(true);connection.setRequestMethod("POST");if (requestEncoding == null || requestEncoding.isEmpty()) {requestEncoding = "UTF-8";}if (responseEncoding == null || responseEncoding.isEmpty()) {responseEncoding = "UTF-8";}if (requestHeader != null && requestHeader.size() > 0) {for (Entry<String, String> entry : requestHeader.entrySet()) {connection.setRequestProperty(entry.getKey(), entry.getValue());}}if (files == null || files.size() == 0) {connection.setRequestProperty("content-type", "application/x-www-form-urlencoded");out = new DataOutputStream(connection.getOutputStream());if (formTexts != null && formTexts.size() > 0) {String formData = "";for (Entry<String, String> entry : formTexts.entrySet()) {formData += entry.getKey() + "=" + entry.getValue() + "&";}formData = formData.substring(0, formData.length() - 1);out.write(formData.toString().getBytes(requestEncoding));}} else {String boundary = "-----------------------------" + String.valueOf(new Date().getTime());connection.setRequestProperty("content-type", "multipart/form-data; boundary=" + boundary);out = new DataOutputStream(connection.getOutputStream());if (formTexts != null && formTexts.size() > 0) {StringBuilder sbFormData = new StringBuilder();for (Entry<String, String> entry : formTexts.entrySet()) {sbFormData.append("--" + boundary + "\r\n");sbFormData.append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"\r\n\r\n");sbFormData.append(entry.getValue() + "\r\n");}out.write(sbFormData.toString().getBytes(requestEncoding));}for (Entry<String, String> entry : files.entrySet()) {String fileName = entry.getKey();String filePath = entry.getValue();if (fileName == null || fileName.isEmpty() || filePath == null || filePath.isEmpty()) {continue;}File file = new File(filePath);if (!file.exists()) {continue;}out.write(("--" + boundary + "\r\n").getBytes(requestEncoding));out.write(("Content-Disposition: form-data; name=\"" + fileName + "\"; filename=\"" + file.getName() + "\"\r\n").getBytes(requestEncoding));out.write(("Content-Type: application/x-msdownload\r\n\r\n").getBytes(requestEncoding));DataInputStream in = new DataInputStream(new FileInputStream(file));int bytes = 0;byte[] bufferOut = new byte[1024];while ((bytes = in.read(bufferOut)) != -1) {out.write(bufferOut, 0, bytes);}in.close();out.write(("\r\n").getBytes(requestEncoding));}//out.write(("--" + boundary + "--").getBytes(requestEncoding));这样写微信公众号开发上传素材有问题                                out.write(("--" + boundary + "--\r\n").getBytes(requestEncoding));}out.flush();out.close();out = null;reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), responseEncoding));String line;while ((line = reader.readLine()) != null) {result += line;}} catch (Exception e) {System.out.println("发送POST请求出现异常！");e.printStackTrace();} finally {try {if (out != null) {out.close();}if (reader != null) {reader.close();}} catch (IOException ex) {ex.printStackTrace();}}return result;}}