一、首先在client端，导入maven相关依赖（httpclient以及json相关依赖）
<dependencies><dependency><groupId>org.apache.httpcomponents</groupId><artifactId>httpclient</artifactId><version>4.5.2</version></dependency><dependency><groupId>net.sf.json-lib</groupId><artifactId>json-lib</artifactId><version>2.4</version></dependency><dependency><groupId>net.sf.ezmorph</groupId><artifactId>ezmorph</artifactId><version>1.0.6</version></dependency><dependency><groupId>commons-collections</groupId><artifactId>commons-collections</artifactId><version>3.2.1</version></dependency><dependency><groupId>commons-beanutils</groupId><artifactId>commons-beanutils</artifactId><version>1.8.3</version></dependency></dependencies>
二、程序实例
import java.io.IOException;import .URI;import java.util.ArrayList;import java.util.List;import java.util.Map;import org.apache.http.Consts;import org.apache.http.NameValuePair;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.utils.URIBuilder;import org.apache.http.entity.ContentType;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;import net.sf.json.JSONObject;public class HttpClientUtil {public static String doGet(String url, Map<String, String> param) {// 创建Httpclient对象CloseableHttpClient httpclient = HttpClients.createDefault();//设置请求超时时间（各项超时参数具体含义链接）RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(10000).setSocketTimeout(10000).build();String resultString = "";CloseableHttpResponse response = null;try {// 创建uriURIBuilder builder = new URIBuilder(url);if (param != null) {for (String key : param.keySet()) {builder.addParameter(key, param.get(key));}}URI uri = builder.build();// 创建http GET请求HttpGet httpGet = new HttpGet(uri);//给这个请求设置请求配置httpGet.setConfig(requestConfig);httpGet.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; rv:6.0.2) Gecko/0101 Firefox/6.0.2");// 执行请求response = httpclient.execute(httpGet);// 判断返回状态是否为200if (response.getStatusLine().getStatusCode() == 200) {resultString = EntityUtils.toString(response.getEntity(), "UTF-8");}} catch (Exception e) {e.printStackTrace();} finally {try {if (response != null) {response.close();}httpclient.close();} catch (IOException e) {e.printStackTrace();}}return resultString;}public static String doPost(String url, Map<String, String> param) {// 创建Httpclient对象CloseableHttpClient httpClient = HttpClients.createDefault();//设置请求超时时间RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(10000).setSocketTimeout(10000).build();CloseableHttpResponse response = null;String resultString = "";try {// 创建Http Post请求HttpPost httpPost = new HttpPost(url);httpPost.setConfig(requestConfig);// 创建参数列表if (param != null) {List<NameValuePair> paramList = new ArrayList<>();for (String key : param.keySet()) {paramList.add(new BasicNameValuePair(key, param.get(key)));}// 模拟表单UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);httpPost.setEntity(entity);}// 执行http请求response = httpClient.execute(httpPost);if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){resultString = EntityUtils.toString(response.getEntity(), "utf-8");}} catch (Exception e) {e.printStackTrace();} finally {try {response.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}return resultString;}public static String doPostJson(String url, String json) {// 创建Httpclient对象CloseableHttpClient httpClient = HttpClients.createDefault();//设置请求超时时间RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(10000).setConnectionRequestTimeout(10000).setSocketTimeout(10000).build();CloseableHttpResponse response = null;String resultString = "";try {// 创建Http Post请求HttpPost httpPost = new HttpPost(url);httpPost.setConfig(requestConfig);// 创建请求内容，发送json数据需要设置contentTypeStringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON));httpPost.setEntity(entity);// 执行http请求response = httpClient.execute(httpPost);if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){resultString = EntityUtils.toString(response.getEntity(), "utf-8");}} catch (Exception e) {e.printStackTrace();} finally {try {response.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}return resultString;} }
补充：各项超时参数具体含义链接
1、发送普通格式数据：
客户端代码：
public static void httpClientTest(){String url="http://localhost/SSMActM/RestTest/restMethod";Map<String,String> map=new HashMap<String,String> ();map.put("name", "bob");map.put("id", "2");String str = HttpClientUtil.doGet(url, map);System.out.println(str);}
服务端：
@RequestMapping(value = "/restMethod")@ResponseBodypublic String restMethod(HttpServletRequest request){String username = request.getParameter("name");return username;}
2、发送json格式数据：
客户端代码：
public static void httpClientJsonTest(){String url="http://localhost/SSMActM/RestTest/restMethod";Map<String,String> map=new HashMap<String,String> ();map.put("name", "bob");map.put("id", "2");//post使用json格式String param=JSONObject.fromObject(map).toString();String str = HttpClientUtil.doPostJson(url,param);System.out.println(str);}
服务端：
@RequestMapping(value = "/restMethod")public String restMethod(HttpServletRequest request){StringBuffer str = new StringBuffer();try {BufferedInputStream in = new BufferedInputStream(request.getInputStream());int i;char c;while ((i=in.read())!=-1) {c=(char)i;str.append(c);}}catch (Exception ex) {ex.printStackTrace();}String string = str.toString();return string;}
