使用HttpClient调用接口的实例讲解

 public class HttpResult { // 响应的状态码 private int code; // 响应的响应体 private String body; get/set… } 

 package cn.xxxxxx.httpclient; import java.util.ArrayList; import java.util.List; import java.util.Map; 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.HttpDelete; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpPut; import org.apache.http.client.utils.URIBuilder; 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; public class APIService { private CloseableHttpClient httpClient; public APIService() { // 1 创建HttpClinet，相当于打开浏览器 this.httpClient = HttpClients.createDefault(); } /** * 带参数的get请求 * * @param url * @param map * @return * @throws Exception */ public HttpResult doGet(String url, Map map) throws Exception { // 声明URIBuilder URIBuilder uriBuilder = new URIBuilder(url); // 判断参数map是否为非空 if (map != null) { // 遍历参数 for (Map.Entry entry : map.entrySet()) { // 设置参数 uriBuilder.setParameter(entry.getKey(), entry.getValue().toString()); } } // 2 创建httpGet对象，相当于设置url请求地址 HttpGet httpGet = new HttpGet(uriBuilder.build()); // 3 使用HttpClient执行httpGet，相当于按回车，发起请求 CloseableHttpResponse response = this.httpClient.execute(httpGet); // 4 解析结果，封装返回对象httpResult，相当于显示相应的结果 // 状态码 // response.getStatusLine().getStatusCode(); // 响应体，字符串，如果response.getEntity()为空，下面这个代码会报错,所以解析之前要做非空的判断 // EntityUtils.toString(response.getEntity(), "UTF-8"); HttpResult httpResult = null; // 解析数据封装HttpResult if (response.getEntity() != null) { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(response.getEntity(), "UTF-8")); } else { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), ""); } // 返回 return httpResult; } /** * 不带参数的get请求 * * @param url * @return * @throws Exception */ public HttpResult doGet(String url) throws Exception { HttpResult httpResult = this.doGet(url, null); return httpResult; } /** * 带参数的post请求 * * @param url * @param map * @return * @throws Exception */ public HttpResult doPost(String url, Map map) throws Exception { // 声明httpPost请求 HttpPost httpPost = new HttpPost(url); // 判断map不为空 if (map != null) { // 声明存放参数的List集合 List params = new ArrayList(); // 遍历map，设置参数到list中 for (Map.Entry entry : map.entrySet()) { params.add(new BasicNameValuePair(entry.getKey(), entry.getValue().toString())); } // 创建form表单对象 UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(params, "UTF-8"); // 把表单对象设置到httpPost中 httpPost.setEntity(formEntity); } // 使用HttpClient发起请求，返回response CloseableHttpResponse response = this.httpClient.execute(httpPost); // 解析response封装返回对象httpResult HttpResult httpResult = null; if (response.getEntity() != null) { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(response.getEntity(), "UTF-8")); } else { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), ""); } // 返回结果 return httpResult; } /** * 不带参数的post请求 * * @param url * @return * @throws Exception */ public HttpResult doPost(String url) throws Exception { HttpResult httpResult = this.doPost(url, null); return httpResult; } /** * 带参数的Put请求 * * @param url * @param map * @return * @throws Exception */ public HttpResult doPut(String url, Map map) throws Exception { // 声明httpPost请求 HttpPut httpPut = new HttpPut(url); // 判断map不为空 if (map != null) { // 声明存放参数的List集合 List params = new ArrayList(); // 遍历map，设置参数到list中 for (Map.Entry entry : map.entrySet()) { params.add(new BasicNameValuePair(entry.getKey(), entry.getValue().toString())); } // 创建form表单对象 UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(params, "UTF-8"); // 把表单对象设置到httpPost中 httpPut.setEntity(formEntity); } // 使用HttpClient发起请求，返回response CloseableHttpResponse response = this.httpClient.execute(httpPut); // 解析response封装返回对象httpResult HttpResult httpResult = null; if (response.getEntity() != null) { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(response.getEntity(), "UTF-8")); } else { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), ""); } // 返回结果 return httpResult; } /** * 带参数的Delete请求 * * @param url * @param map * @return * @throws Exception */ public HttpResult doDelete(String url, Map map) throws Exception { // 声明URIBuilder URIBuilder uriBuilder = new URIBuilder(url); // 判断参数map是否为非空 if (map != null) { // 遍历参数 for (Map.Entry entry : map.entrySet()) { // 设置参数 uriBuilder.setParameter(entry.getKey(), entry.getValue().toString()); } } // 2 创建httpGet对象，相当于设置url请求地址 HttpDelete httpDelete = new HttpDelete(uriBuilder.build()); // 3 使用HttpClient执行httpGet，相当于按回车，发起请求 CloseableHttpResponse response = this.httpClient.execute(httpDelete); // 4 解析结果，封装返回对象httpResult，相当于显示相应的结果 // 状态码 // response.getStatusLine().getStatusCode(); // 响应体，字符串，如果response.getEntity()为空，下面这个代码会报错,所以解析之前要做非空的判断 // EntityUtils.toString(response.getEntity(), "UTF-8"); HttpResult httpResult = null; // 解析数据封装HttpResult if (response.getEntity() != null) { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(response.getEntity(), "UTF-8")); } else { httpResult = new HttpResult(response.getStatusLine().getStatusCode(), ""); } // 返回 return httpResult; } }

 package cn.xxxxxx.httpclient.test; import java.util.HashMap; import java.util.Map; import org.junit.Before; import org.junit.Test; import cn.itcast.httpclient.APIService; import cn.itcast.httpclient.HttpResult; public class APIServiceTest { private APIService apiService; @Before public void init() { this.apiService = new APIService(); } // 查询 @Test public void testQueryItemById() throws Exception { // http://manager.aaaaaa.com/rest/item/interface/{id} String url = "http://manager.aaaaaa.com/rest/item/interface/42"; HttpResult httpResult = this.apiService.doGet(url); System.out.println(httpResult.getCode()); System.out.println(httpResult.getBody()); } // 新增 @Test public void testSaveItem() throws Exception { // http://manager.aaaaaa.com/rest/item/interface/{id} String url = "http://manager.aaaaaa.com/rest/item/interface"; Map map = new HashMap(); // title=测试RESTful风格的接口&price=1000&num=1&cid=888&status=1 map.put("title", "测试APIService调用新增接口"); map.put("price", "1000"); map.put("num", "1"); map.put("cid", "666"); map.put("status", "1"); HttpResult httpResult = this.apiService.doPost(url, map); System.out.println(httpResult.getCode()); System.out.println(httpResult.getBody()); } // 修改 @Test public void testUpdateItem() throws Exception { // http://manager.aaaaaa.com/rest/item/interface/{id} String url = "http://manager.aaaaaa.com/rest/item/interface"; Map map = new HashMap(); // title=测试RESTful风格的接口&price=1000&num=1&cid=888&status=1 map.put("title", "测试APIService调用修改接口"); map.put("id", "44"); HttpResult httpResult = this.apiService.doPut(url, map); System.out.println(httpResult.getCode()); System.out.println(httpResult.getBody()); } // 删除 @Test public void testDeleteItemById() throws Exception { // http://manager.aaaaaa.com/rest/item/interface/{id} String url = "http://manager.aaaaaa.com/rest/item/interface/44"; HttpResult httpResult = this.apiService.doDelete(url, null); System.out.println(httpResult.getCode()); System.out.println(httpResult.getBody()); } }