最近，公司需要用到Java代码后台实现文件上传和下载，一开始选择java原生HttpUrlConnnection，找了一些博客文章，发现使用起来不是那么方便。之后选择了HttpClient，原来公司有一个HttpClient的工具，依赖的版本是4.2.x，但不包含文件上传下载部分，本人比较懒，于是网上找了一些代码，发现许多使用例子要么比较老，要么比较新，自从HttpClient版本从4.0开始，发现api变化非常大，很多api已经Deprecated了，于是打算自己搜集一些片段重新写一个适合自己项目的工具。
本文参考了：
http://www.oschina.NET/code/snippet_216580_38020
http://jingyan.baidu.com/article/154b46317353d228ca8f4112.html
以及官方压缩包中的pdf文档。
转载请注明出处：http://blog.csdn.Net/comven2/article/details/52180620
本工具中依赖的jar包如下：
httpclient-4.5.2.jar
httpcore-4.4.5.jar
httpmime-4.5.2.jar
commons-logging-1.1.1.jar
log4j-1.2.14.jar
slf4j-api-1.7.13.jar
slf4j-log4j12-1.7.9.jar
由于日志习惯用slf4j的api所以多了几个日志包
由于本人懒人一枚，日常工作生活中，多偏向应用，拿来主义居多，部分细节未深究，有不足的地方还请大侠指正。
以下为详细代码，整个工具类，代码有点长：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InterruptedIOException; import java.io.UnsupportedEncodingException; import java.net.UnknownHostException; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLException; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import org.apache.http.HttpEntity; import org.apache.http.HttpEntityEnclosingRequest; import org.apache.http.HttpRequest; import org.apache.http.NameValuePair; import org.apache.http.ParseException; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpRequestRetryHandler; import org.apache.http.client.config.AuthSchemes; import org.apache.http.client.config.CookieSpecs; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.config.RequestConfig.Builder; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.protocol.HttpClientContext; import org.apache.http.config.Registry; import org.apache.http.config.RegistryBuilder; import org.apache.http.conn.ConnectTimeoutException; import org.apache.http.conn.socket.ConnectionSocketFactory; import org.apache.http.conn.socket.PlainConnectionSocketFactory; import org.apache.http.conn.ssl.NoopHostnameVerifier; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.entity.ContentType; import org.apache.http.entity.StringEntity; import org.apache.http.entity.mime.HttpMultipartMode; import org.apache.http.entity.mime.MultipartEntityBuilder; import org.apache.http.entity.mime.content.FileBody; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.apache.http.message.BasicNameValuePair; import org.apache.http.protocol.HttpContext; import org.apache.http.util.CharsetUtils; import org.apache.http.util.EntityUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Http辅助工具类 * @author dj * */ public class HttpHelper { private static Logger logger = LoggerFactory.getLogger(HttpHelper.class); private static final String DEFAULT_CHARSET = "UTF-8";//默认请求编码 private static final int DEFAULT_SOCKETTIMEOUT = 5000;//默认等待响应时间(毫秒) private static final int DEFAULT_RETRY_TIMES = 0;//默认执行重试的次数 public HttpHelper() { } /** * 自测用的main方法 * * @param args */ public static void main(String[] args) { } /** * 创建一个默认的可关闭的HttpClient * * @return */ public static CloseableHttpClient createHttpClient() { return createHttpClient(DEFAULT_RETRY_TIMES, DEFAULT_SOCKETTIMEOUT); } /** * 创建一个可关闭的HttpClient * * @param socketTimeout * 请求获取数据的超时时间 * @return */ public static CloseableHttpClient createHttpClient(int socketTimeout) { return createHttpClient(DEFAULT_RETRY_TIMES, socketTimeout); } /** * 创建一个可关闭的HttpClient * * @param socketTimeout * 请求获取数据的超时时间 * @param retryTimes * 重试次数，小于等于0表示不重试 * @return */ public static CloseableHttpClient createHttpClient(int retryTimes, int socketTimeout) { Builder builder = RequestConfig.custom(); builder.setConnectTimeout(5000);// 设置连接超时时间，单位毫秒 builder.setConnectionRequestTimeout(1000);// 设置从connect Manager获取Connection 超时时间，单位毫秒。这个属性是新加的属性，因为目前版本是可以共享连接池的。 builder.setSocketTimeout(socketTimeout);// 请求获取数据的超时时间，单位毫秒。 如果访问一个接口，多少时间内无法返回数据，就直接放弃此次调用。 RequestConfig defaultRequestConfig = builder.setCookieSpec(CookieSpecs.STANDARD_STRICT).setExpectContinueEnabled(true).setTargetPreferredAuthSchemes(Arrays.asList(AuthSchemes.NTLM, AuthSchemes.DIGEST)).setProxyPreferredAuthSchemes(Arrays.asList(AuthSchemes.BASIC)).build(); // 开启HTTPS支持 enableSSL(); // 创建可用Scheme Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory> create().register("http", PlainConnectionSocketFactory.INSTANCE).register("https", socketFactory).build(); // 创建ConnectionManager，添加Connection配置信息 PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry); HttpClientBuilder httpClientBuilder = HttpClients.custom(); if (retryTimes > 0) { setRetryHandler(httpClientBuilder, retryTimes); } CloseableHttpClient httpClient = httpClientBuilder.setConnectionManager(connectionManager).setDefaultRequestConfig(defaultRequestConfig).build(); return httpClient; } /** * 执行HttpGet请求 * * @param httpClient HttpClient客户端实例，传入null会自动创建一个 * @param url 请求的远程地址 * @param reffer reffer信息，可传null * @param cookie cookies信息，可传null * @param charset 请求编码，默认UTF8 * @param closeHttpClient 执行请求结束后是否关闭HttpClient客户端实例 * @return * @throws ClientProtocolException * @throws IOException */ public static String executeGet(CloseableHttpClient httpClient, String url, String reffer, String cookie, String charset, boolean closeHttpClient) throws IOException { CloseableHttpResponse httpResponse = null; try { if (httpClient == null) { httpClient = createHttpClient(); } HttpGet get = new HttpGet(url); if (cookie != null && !"".equals(cookie)) { get.setHeader("Cookie", cookie); } if (reffer != null && !"".equals(reffer)) { get.setHeader("Reffer", reffer); } charset = getCharset(charset); httpResponse = httpClient.execute(get); return getResult(httpResponse, charset); } finally { if (httpResponse != null) { try { httpResponse.close(); } catch (Exception e) { } } if (closeHttpClient && httpClient != null) { try { httpResponse.close(); } catch (Exception e) { } } } } /** * 执行HttpPost请求 * * @param httpClient HttpClient客户端实例，传入null会自动创建一个 * @param url 请求的远程地址 * @param paramsObj 提交的参数信息，目前支持Map,和String(JSON\xml) * @param reffer reffer信息，可传null * @param cookie cookies信息，可传null * @param charset 请求编码，默认UTF8 * @param closeHttpClient 执行请求结束后是否关闭HttpClient客户端实例 * @return * @throws IOException * @throws ClientProtocolException */ public static String executePost(CloseableHttpClient httpClient, String url, Object paramsObj, String reffer, String cookie, String charset, boolean closeHttpClient) throws IOException { CloseableHttpResponse httpResponse = null; try { if (httpClient == null) { httpClient = createHttpClient(); } HttpPost post = new HttpPost(url); if (cookie != null && !"".equals(cookie)) { post.setHeader("Cookie", cookie); } if (reffer != null && !"".equals(reffer)) { post.setHeader("Reffer", reffer); } charset = getCharset(charset); // 设置参数 HttpEntity httpEntity = getEntity(paramsObj, charset); if (httpEntity != null) { post.setEntity(httpEntity); } httpResponse = httpClient.execute(post); return getResult(httpResponse, charset); } finally { if (httpResponse != null) { try { httpResponse.close(); } catch (Exception e2) { } } if (closeHttpClient && httpClient != null) { try { httpClient.close(); } catch (Exception e2) { } } } } /** * 执行文件上传 * @param httpClient HttpClient客户端实例，传入null会自动创建一个 * @param remoteFileUrl 远程接收文件的地址 * @param localFilePath 本地文件地址 * @param charset 请求编码，默认UTF-8 * @param closeHttpClient 执行请求结束后是否关闭HttpClient客户端实例 * @return * @throws ClientProtocolException * @throws IOException */ public static String executeUploadFile(CloseableHttpClient httpClient, String remoteFileUrl, String localFilePath, String charset, boolean closeHttpClient) throws ClientProtocolException, IOException { CloseableHttpResponse httpResponse = null; try { if (httpClient == null) { httpClient = createHttpClient(); } // 把文件转换成流对象FileBody File localFile = new File(localFilePath); FileBody fileBody = new FileBody(localFile); // 以浏览器兼容模式运行，防止文件名乱码。 HttpEntity reqEntity = MultipartEntityBuilder.create().setMode(HttpMultipartMode.BROWSER_COMPATIBLE).addPart("uploadFile", fileBody).setCharset(CharsetUtils.get("UTF-8")).build(); // uploadFile对应服务端类的同名属性<File类型> // .addPart("uploadFileName", uploadFileName) // uploadFileName对应服务端类的同名属性<String类型> HttpPost httpPost = new HttpPost(remoteFileUrl); httpPost.setEntity(reqEntity); httpResponse = httpClient.execute(httpPost); return getResult(httpResponse, charset); } finally { if (httpResponse != null) { try { httpResponse.close(); } catch (Exception e) { } } if (closeHttpClient && httpClient != null) { try { httpClient.close(); } catch (Exception e) { } } } } /** * 执行文件下载 * @param httpClient HttpClient客户端实例，传入null会自动创建一个 * @param remoteFileUrl 远程下载文件地址 * @param localFilePath 本地存储文件地址 * @param charset 请求编码，默认UTF-8 * @param closeHttpClient 执行请求结束后是否关闭HttpClient客户端实例 * @return * @throws ClientProtocolException * @throws IOException */ public static boolean executeDownloadFile(CloseableHttpClient httpClient, String remoteFileUrl, String localFilePath, String charset, boolean closeHttpClient) throws ClientProtocolException, IOException { CloseableHttpResponse response = null; InputStream in = null; FileOutputStream fout = null; try { HttpGet httpget = new HttpGet(remoteFileUrl); response = httpClient.execute(httpget); HttpEntity entity = response.getEntity(); if (entity == null) { return false; } in = entity.getContent(); File file = new File(localFilePath); fout = new FileOutputStream(file); int l = -1; byte[] tmp = new byte[1024]; while ((l = in.read(tmp)) != -1) { fout.write(tmp, 0, l); // 注意这里如果用OutputStream.write(buff)的话，图片会失真 } // 将文件输出到本地 fout.flush(); EntityUtils.consume(entity); return true; } finally { // 关闭低层流。 if (fout != null) { try { fout.close(); } catch (Exception e) { } } if (response != null) { try { response.close(); } catch (Exception e) { } } if (closeHttpClient && httpClient != null) { try { httpClient.close(); } catch (Exception e) { } } } } /** * 获取请求的 * * @param paramsObj * @param charset * @return * @throws UnsupportedEncodingException */ private static HttpEntity getEntity(Object paramsObj, String charset) throws UnsupportedEncodingException { if (paramsObj == null) { logger.info("当前未传入参数信息，无法生成HttpEntity"); return null; } if (Map.class.isInstance(paramsObj)) {// 当前是map数据 @SuppressWarnings("unchecked") Map<String, String> paramsMap = (Map<String, String>) paramsObj; List<NameValuePair> list = getNameValuePairs(paramsMap); UrlEncodedFormEntity httpEntity = new UrlEncodedFormEntity(list, charset); httpEntity.setContentType(ContentType.APPLICATION_FORM_URLENCODED.getMimeType()); return httpEntity; } else if (String.class.isInstance(paramsObj)) {// 当前是string对象，可能是 String paramsStr = paramsObj.toString(); StringEntity httpEntity = new StringEntity(paramsStr, charset); logger.info("数据:" + paramsStr); if (paramsStr.startsWith("{")) { httpEntity.setContentType(ContentType.APPLICATION_JSON.getMimeType()); } else if (paramsStr.startsWith("<")) { httpEntity.setContentType(ContentType.APPLICATION_XML.getMimeType()); } else { httpEntity.setContentType(ContentType.APPLICATION_FORM_URLENCODED.getMimeType()); } return httpEntity; } else { logger.info("当前传入参数不能识别类型，无法生成HttpEntity"); } return null; } /** * 从结果中获取出String数据 * * @param httpResponse * @param charset * @return * @throws ParseException * @throws IOException */ private static String getResult(CloseableHttpResponse httpResponse, String charset) throws ParseException, IOException { String result = null; if (httpResponse == null) { return result; } HttpEntity entity = httpResponse.getEntity(); if (entity == null) { return result; } logger.info("StatusCode is " + httpResponse.getStatusLine().getStatusCode()); result = EntityUtils.toString(entity, charset); EntityUtils.consume(entity);// 关闭应该关闭的资源，适当的释放资源 ;也可以把底层的流给关闭了 return result; } /** * 转化请求编码 * * @param charset * @return */ private static String getCharset(String charset) { return charset == null ? DEFAULT_CHARSET : charset; } /** * 将map类型参数转化为NameValuePair集合方式 * @param paramsMap * @return */ private static List<NameValuePair> getNameValuePairs(Map<String, String> paramsMap) { List<NameValuePair> list = new ArrayList<>(); if (paramsMap == null || paramsMap.isEmpty()) { return list; } for (Entry<String, String> entry : paramsMap.entrySet()) { list.add(new BasicNameValuePair(entry.getKey(), entry.getValue())); } return list; } /** * 开启SSL支持 */ private static void enableSSL() { try { SSLContext context = SSLContext.getInstance("TLS"); context.init(null, new TrustManager[] { manager }, null); socketFactory = new SSLConnectionSocketFactory(context, NoopHostnameVerifier.INSTANCE); } catch (Exception e) { e.printStackTrace(); } } private static SSLConnectionSocketFactory socketFactory; // https网站一般情况下使用了安全系数较低的SHA-1签名，因此首先我们在调用SSL之前需要重写验证方法，取消检测SSL。 private static TrustManager manager = new X509TrustManager() { @Override public X509Certificate[] getAcceptedIssuers() { return null; } @Override public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException { // } @Override public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException { // } }; /** * 为httpclient设置重试信息 * * @param httpClientBuilder * @param retryTimes */ private static void setRetryHandler(HttpClientBuilder httpClientBuilder, final int retryTimes) { HttpRequestRetryHandler myRetryHandler = new HttpRequestRetryHandler() { public boolean retryRequest(IOException exception, int executionCount, HttpContext context) { if (executionCount >= retryTimes) { // Do not retry if over max retry count return false; } if (exception instanceof InterruptedIOException) { // Timeout return false; } if (exception instanceof UnknownHostException) { // Unknown host return false; } if (exception instanceof ConnectTimeoutException) { // Connection refused return false; } if (exception instanceof SSLException) { // SSL handshake exception return false; } HttpClientContext clientContext = HttpClientContext.adapt(context); HttpRequest request = clientContext.getRequest(); boolean idempotent = !(request instanceof HttpEntityEnclosingRequest); if (idempotent) { // 如果请求被认为是幂等的，那么就重试 // Retry if the request is considered idempotent return true; } return false; } }; httpClientBuilder.setRetryHandler(myRetryHandler); } }
