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());

    }

}