1.情景展示

　　java发送get请求、post请求（form表单、json数据）至另一服务器；

　　可设置HTTP请求头部信息，可以接收服务器返回cookie信息，可以上传文件等；

2.代码实现

所需jar包：httpcore-4.4.1.jar；httpclient-4.4.1.jar；httpmime-4.4.1.jar；epoint-utils-9.3.3.jar

import java.io.File;import java.io.IOException;import java.io.InputStream;import java.nio.charset.Charset;import java.security.GeneralSecurityException;import java.security.cert.CertificateException;import java.security.cert.X509Certificate;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import javax.net.ssl.HostnameVerifier;import javax.net.ssl.SSLContext;import javax.net.ssl.SSLSession;import org.apache.http.Header;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.config.RequestConfig;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.client.methods.HttpDelete;import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPatch;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.methods.HttpRequestBase;import org.apache.http.conn.ssl.SSLConnectionSocketFactory;import org.apache.http.conn.ssl.TrustStrategy;import org.apache.http.entity.ContentType;import org.apache.http.entity.StringEntity;import org.apache.http.entity.mime.MultipartEntityBuilder;import org.apache.http.entity.mime.content.StringBody;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;import org.apache.http.message.BasicNameValuePair;import org.apache.http.ssl.SSLContextBuilder;import org.apache.http.util.EntityUtils;import com.epoint.core.utils.string.StringUtil;/*** HttpClient工具类，使用http-client包实现，原先的common-httpclient已经淘汰** @作者 ko* @version [版本号, 2017年10月18日]*/public class HttpUtil{private static PoolingHttpClientConnectionManager connMgr;private static RequestConfig requestConfig;private static final int MAX_TIMEOUT = 7000;/*** 直接以流返回*/public static final int RTN_TYPE_1 = 1;/*** 直接以string返回*/public static final int RTN_TYPE_2 = 2;/*** 以map返回，reslut:接口结果string;statusCode:http状态码*/public static final int RTN_TYPE_3 = 3;/*** 以map返回，reslut:接口结果string;statusCode:http状态码;cookie:response的cookie* cookie值键值对，格式 key1=value1;key2=value2;...*/public static final int RTN_TYPE_4 = 4;/*** 默认上传文件的文件流或file 的key Name*/private static final String DEFAULT_BINARYBODY_KEYNAME = "file";static {// 设置连接池connMgr = new PoolingHttpClientConnectionManager();// 设置连接池大小connMgr.setMaxTotal(100);connMgr.setDefaultMaxPerRoute(connMgr.getMaxTotal());// 在提交请求之前 测试连接是否可用connMgr.setValidateAfterInactivity(1);RequestConfig.Builder configBuilder = RequestConfig.custom();// 设置连接超时configBuilder.setConnectTimeout(MAX_TIMEOUT);// 设置读取超时configBuilder.setSocketTimeout(MAX_TIMEOUT);// 设置从连接池获取连接实例的超时configBuilder.setConnectionRequestTimeout(MAX_TIMEOUT);requestConfig = configBuilder.build();}/*** 发送 GET请求** @param apiUrl* API接口URL* @return String 响应内容*/public static String doGet(String apiUrl) {return doHttp(apiUrl, null, "get", RTN_TYPE_2);}/*** 发送POST请求** @param apiUrl* API接口URL* @param params* K-V参数* @return String 响应内容*/public static String doPost(String apiUrl, Map<String, Object> params) {return doHttp(apiUrl, params, "post", RTN_TYPE_2);}/*** 发送POST请求** @param apiUrl* API接口URL* @param json* json参数* @return String 响应内容*/public static String doPostJson(String apiUrl, String json) {return doHttp(apiUrl, json, "post", RTN_TYPE_2);}/*** 发送 http 请求** @param apiUrl* API接口URL* @param params* {Map<String, Object> K-V形式、json字符串}* @param method* {null、或者post:POST请求、patch:PATCH请求、delete:DELETE请求、get:GET请求}* @param type* {HttpUtil.RTN_TYPE_1:请求返回stream(此时流需要在外部手动关闭);HttpUtil.* RTN_TYPE_2:string;HttpUtil.RTN_TYPE_3:返回一个map,map包含结果(* 结果是string形式)以及http状态码;HttpUtil.RTN_TYPE_4:返回一个map,map包含结果(* 结果是string形式), http状态码和cookie;其他情况返回string}* 如果结果是个map,key为:result,statusCode,cookie,分别返回 结果* string,http状态码，cookie; cookie值键值对，格式* key1=value1;key2=value2;...* @return stream或 string 或 map*/public static <T> T doHttp(String apiUrl, Object params, String method, int type) {return doHttp(apiUrl, null, params, method, type);}/*** 发送 http 请求** @param apiUrl* API接口URL* @param headerMap* header信息Map<String, String>,可设置cookie* @param params* {Map<String, Object> K-V形式、json字符串}* @param method* {null、或者post:POST请求、patch:PATCH请求、delete:DELETE请求、get:GET请求}* @param type* {HttpUtil.RTN_TYPE_1:请求返回stream(此时流需要在外部手动关闭);HttpUtil.* RTN_TYPE_2:string;HttpUtil.RTN_TYPE_3:返回一个map,map包含结果(* 结果是string形式)以及http状态码;HttpUtil.RTN_TYPE_4:返回一个map,map包含结果(* 结果是string形式), http状态码和cookie;其他情况返回string}* 如果结果是个map,key为:result,statusCode,cookie,分别返回 结果* string,http状态码，cookie; cookie值键值对，格式* key1=value1;key2=value2;...* @return stream或 string 或 map*/public static <T> T doHttp(String apiUrl, Map<String, String> headerMap, Object params, String method, int type) {CloseableHttpClient httpClient = null;if (isSSL(apiUrl)) {httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory()).setConnectionManager(connMgr).setDefaultRequestConfig(requestConfig).build();}else {httpClient = HttpClients.createDefault();}return doHttp(httpClient, apiUrl, headerMap, params, method, type);}/*** 发送 http 请求** @param httpClient* httpclient对象 由外部传入，用户 需要保持登录状态等情况 此时如果要ssl,那么要在外部加入ssl特性* httpClient =* HttpClients.custom().setSSLSocketFactory(HttpUtil.* createSSLConnSocketFactory())* .setConnectionManager(HttpUtil.getConnMgr()).* setDefaultRequestConfig(HttpUtil..getRequestConfig()).build();* @param apiUrl* API接口URL* @param headerMap* header信息Map<String, String>,可设置cookie** @param params* {Map<String, Object> K-V形式、json字符串}* @param method* {null、或者post:POST请求、patch:PATCH请求、delete:DELETE请求、get:GET请求}* @param type* {HttpUtil.RTN_TYPE_1:请求返回stream(此时流需要在外部手动关闭);HttpUtil.* RTN_TYPE_2:string;HttpUtil.RTN_TYPE_3:返回一个map,map包含结果(* 结果是string形式)以及http状态码;HttpUtil.RTN_TYPE_4:返回一个map,map包含结果(* 结果是string形式), http状态码和cookie;其他情况返回string}* 如果结果是个map,key为:result,statusCode,cookie,分别返回 结果* string,http状态码，cookie; cookie值键值对，格式* key1=value1;key2=value2;...* @return stream或 string 或 map*/@SuppressWarnings("unchecked")public static <T> T doHttp(CloseableHttpClient httpClient, String apiUrl, Map<String, String> headerMap,Object params, String method, int type) {HttpRequestBase httpPost = null;if (StringUtil.isNotBlank(method)) {if ("patch".equalsIgnoreCase(method)) {httpPost = new HttpPatch(apiUrl);}else if ("delete".equalsIgnoreCase(method)) {httpPost = new HttpDelete(apiUrl);}else if ("get".equalsIgnoreCase(method)) {httpPost = new HttpGet(apiUrl);}else if ("post".equalsIgnoreCase(method)) {httpPost = new HttpPost(apiUrl);}}else {httpPost = new HttpPost(apiUrl);}CloseableHttpResponse response = null;try {// 设置header信息if (headerMap != null && !headerMap.isEmpty()) {for (Map.Entry<String, String> entry : headerMap.entrySet()) {httpPost.addHeader(entry.getKey(), entry.getValue());}}if (isSSL(apiUrl)) {httpPost.setConfig(requestConfig);}// 参数不为null、要处理参数if (params != null) {// get请求拼接在url后面if (httpPost instanceof HttpGet) {StringBuffer param = new StringBuffer();if (params instanceof Map) {Map<String, Object> paramsConvert = (Map<String, Object>) params;int i = 0;for (String key : paramsConvert.keySet()) {if (i == 0)param.append("?");elseparam.append("&");param.append(key).append("=").append(paramsConvert.get(key));i++;}}else {param.append("?" + params.toString());}apiUrl += param;}// delete请求暂不处理else if (!(httpPost instanceof HttpDelete)) {// K-V形式if (params instanceof Map) {Map<String, Object> paramsConvert = (Map<String, Object>) params;List<NameValuePair> pairList = new ArrayList<>(paramsConvert.size());for (Map.Entry<String, Object> entry : paramsConvert.entrySet()) {NameValuePair pair = new BasicNameValuePair(entry.getKey(),entry.getValue() == null ? "" : entry.getValue().toString());pairList.add(pair);}((HttpEntityEnclosingRequestBase) httpPost).setEntity(new UrlEncodedFormEntity(pairList, Charset.forName("UTF-8")));}// json格式else {StringEntity stringEntity = new StringEntity(params.toString(), "UTF-8");stringEntity.setContentEncoding("UTF-8");stringEntity.setContentType("application/json");((HttpEntityEnclosingRequestBase) httpPost).setEntity(stringEntity);}}}response = httpClient.execute(httpPost);// int statusCode = response.getStatusLine().getStatusCode();// if (statusCode != HttpStatus.SC_OK) {// return null;// }HttpEntity entity = response.getEntity();if (entity != null) {if (type == RTN_TYPE_1) {return (T) entity.getContent();}else if (RTN_TYPE_2 == type) {return (T) EntityUtils.toString(entity, "UTF-8");}else if (RTN_TYPE_3 == type || RTN_TYPE_4 == type) {Map<String, String> rtnMap = new HashMap<String, String>();rtnMap.put("result", EntityUtils.toString(entity, "UTF-8"));rtnMap.put("statusCode", response.getStatusLine().getStatusCode() + "");if (RTN_TYPE_4 == type) {rtnMap.put("cookie", getCookie(response));}return (T) rtnMap;}else {return (T) EntityUtils.toString(entity, "UTF-8");}}}catch (Exception e) {e.printStackTrace();}finally {if (response != null && type != RTN_TYPE_1) {try {EntityUtils.consume(response.getEntity());}catch (IOException e) {e.printStackTrace();}}}return null;}/*** 上传附件(post形式)** @param url* 请求地址* @param headerMap* header参数map Map<String, String>* @param paramMap* 额外的参数map,Map<String, String>* @param file* 可以选择本地文件上传；如果传了file，又传了fileName，那么文件名以fileName为准，否则 是file的文件名* @param fileName* 以流传输时，必须指定文件名* @param ssl* 是否需要ssl* @return result,返回上传结果，如果接口没有返回值，则为状态码*/public static String upload(String url, Map<String, String> headerMap, Map<String, String> paramMap, File file,String fileName, boolean ssl) {return upload(url, headerMap, paramMap, file, null, fileName, ssl);}/*** 上传附件(post形式)** @param url* 请求地址* @param headerMap* header参数map Map<String, String>* @param paramMap* 额外的参数map,Map<String, String>* @param in* 文件流* @param fileName* 以流传输时，必须指定文件名* @param ssl* 是否需要ssl* @return result,返回上传结果，如果接口没有返回值，则为状态码*/public static String upload(String url, Map<String, String> headerMap, Map<String, String> paramMap, InputStream in,String fileName, boolean ssl) {return upload(url, headerMap, paramMap, null, in, fileName, ssl);}/*** 上传附件(post形式)** @param httpClient* 外部传入httpClient* @param url* 请求地址* @param headerMap* header参数map Map<String, String>* @param paramMap* 额外的参数map,Map<String, String>* @param file* 可以选择本地文件上传；如果传了file，又传了fileName，那么文件名以fileName为准，否则 是file的文件名* @param fileName* 以流传输时，必须指定文件名* @param ssl* 是否需要ssl* @return result,返回上传结果，如果接口没有返回值，则为状态码*/public static String upload(CloseableHttpClient httpClient, String url, Map<String, String> headerMap,Map<String, String> paramMap, File file, String fileName, boolean ssl) {return upload(httpClient, url, headerMap, paramMap, file, null, fileName, ssl);}/*** 上传附件(post形式)** @param httpClient* 外部传入httpClient* @param url* 请求地址* @param headerMap* header参数map Map<String, String>* @param paramMap* 额外的参数map,Map<String, String>* @param in* 文件流* @param fileName* 以流传输时，必须指定文件名* @param ssl* 是否需要ssl* @return result,返回上传结果，如果接口没有返回值，则为状态码*/public static String upload(CloseableHttpClient httpClient, String url, Map<String, String> headerMap,Map<String, String> paramMap, InputStream in, String fileName, boolean ssl) {return upload(httpClient, url, headerMap, paramMap, null, in, fileName, ssl);}/*** 上传附件(post形式)** @param url* 请求地址* @param headerMap* header参数map Map<String, String>* @param paramMap* 额外的参数map,Map<String, String>* @param file* 可以选择本地文件上传，file,in互斥；如果传了file，又传了fileName，那么文件名以fileName为准，否则* 是file的文件名* @param in* 文件流* @param fileName* 以流传输时，必须指定文件名* @param ssl* 是否需要ssl* @return result,返回上传结果，如果接口没有返回值，则为状态码*/private static String upload(String url, Map<String, String> headerMap, Map<String, String> paramMap, File file,InputStream in, String fileName, boolean ssl) {CloseableHttpClient httpClient = null;if (ssl) {httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory()).setConnectionManager(connMgr).setDefaultRequestConfig(requestConfig).build();}else {httpClient = HttpClients.createDefault();}return upload(httpClient, url, headerMap, paramMap, file, in, fileName, ssl);}/*** 上传附件(post形式)** @param httpClient* 外部传入httpClient* @param url* 请求地址* @param headerMap* header参数map Map<String, String>* @param paramMap* 额外的参数map,Map<String, String>* @param file* 可以选择本地文件上传，file,in互斥；如果传了file，又传了fileName，那么文件名以fileName为准，否则* 是file的文件名* @param in* 文件流* @param fileName* 以流传输时，必须指定文件名* @param ssl* 是否需要ssl* @return result,返回上传结果，如果接口没有返回值，则为状态码*/private static String upload(CloseableHttpClient httpClient, String url, Map<String, String> headerMap,Map<String, String> paramMap, File file, InputStream in, String fileName, boolean ssl) {String result = "";CloseableHttpResponse response = null;try {HttpPost httpPost = new HttpPost(url);// 设置header信息if (headerMap != null && !headerMap.isEmpty()) {for (Map.Entry<String, String> entry : headerMap.entrySet()) {httpPost.addHeader(entry.getKey(), entry.getValue());}}if (ssl) {httpPost.setConfig(requestConfig);}MultipartEntityBuilder builder = MultipartEntityBuilder.create();// 选择以file形式上传if (file != null && file.exists()) {if (StringUtil.isNotBlank(fileName)) {builder.addBinaryBody(DEFAULT_BINARYBODY_KEYNAME, file, ContentType.DEFAULT_BINARY, fileName);}else {builder.addBinaryBody(DEFAULT_BINARYBODY_KEYNAME, file);}}// 以流上传else if (in != null && StringUtil.isNotBlank(fileName)) {builder.addBinaryBody(DEFAULT_BINARYBODY_KEYNAME, in, ContentType.DEFAULT_BINARY, fileName);}if (paramMap != null && !paramMap.isEmpty()) {for (Map.Entry<String, String> entry : paramMap.entrySet()) {builder.addPart(entry.getKey(), new StringBody(entry.getValue(), ContentType.TEXT_PLAIN));}}HttpEntity reqEntity = builder.build();httpPost.setEntity(reqEntity);response = httpClient.execute(httpPost);HttpEntity entity = response.getEntity();if (entity != null) {result = EntityUtils.toString(entity, "UTF-8");}else {result = response.getStatusLine().getStatusCode() + "";}}catch (Exception e) {e.printStackTrace();}finally {if (response != null) {try {EntityUtils.consume(response.getEntity());}catch (IOException e) {e.printStackTrace();}}}return result;}private static String getCookie(HttpResponse httpResponse) {Map<String, String> cookieMap = new HashMap<String, String>(64);Header headers[] = httpResponse.getHeaders("Set-Cookie");if (headers == null || headers.length == 0) {return null;}String cookie = "";for (int i = 0; i < headers.length; i++) {cookie += headers[i].getValue();if (i != headers.length - 1) {cookie += ";";}}String cookies[] = cookie.split(";");for (String c : cookies) {c = c.trim();if (cookieMap.containsKey(c.split("=")[0])) {cookieMap.remove(c.split("=")[0]);}cookieMap.put(c.split("=")[0],c.split("=").length == 1 ? "" : (c.split("=").length == 2 ? c.split("=")[1] : c.split("=", 2)[1]));}String cookiesTmp = "";for (String key : cookieMap.keySet()) {cookiesTmp += key + "=" + cookieMap.get(key) + ";";}return cookiesTmp.substring(0, cookiesTmp.length() - 2);}/*** 创建SSL安全连接** @return*/public static SSLConnectionSocketFactory createSSLConnSocketFactory() {SSLConnectionSocketFactory sslsf = null;try {SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy(){public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {return true;}}).build();sslsf = new SSLConnectionSocketFactory(sslContext, new HostnameVerifier(){@Overridepublic boolean verify(String arg0, SSLSession arg1) {return true;}});}catch (GeneralSecurityException e) {e.printStackTrace();}return sslsf;}public static PoolingHttpClientConnectionManager getConnMgr() {return connMgr;}public static RequestConfig getRequestConfig() {return requestConfig;}private static boolean isSSL(String apiUrl) {if (apiUrl.indexOf("https") != -1 ) {return true;}else {return false;}}}

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