使用HttpClient调用接口

一，编写返回对象

public class HttpResult {
// 响应的状态码
private int code;

// 响应的响应体
private String body;
get/set…
}

二，封装HttpClient

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<String, Object> 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<String, Object> 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<String, Object> 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<NameValuePair> params = new ArrayList<NameValuePair>();

            // 遍历map，设置参数到list中

            for (Map.Entry<String, Object> 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<String, Object> 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<NameValuePair> params = new ArrayList<NameValuePair>();

            // 遍历map，设置参数到list中

            for (Map.Entry<String, Object> 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<String, Object> 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<String, Object> 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;

    }

}

三，调用接口

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<String, Object> map = new HashMap<String, Object>();

        // 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<String, Object> map = new HashMap<String, Object>();

        // 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());

    }

}