使用HttpClient调用外部系统接口

Myth丶恋晨 2022-05-14 04:59 254阅读 0赞

package xx;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.ParseException;
    import org.apache.http.client.ClientProtocolException;
    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.HttpGet;
    import org.apache.http.client.methods.HttpPost;
    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 java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.util.ArrayList;
    import java.util.List;
    
    /**
     * 调用外部接口
     *
     * @author 
     * @date 2018/9/3 09:54
     */
    public class HttpClient {
        /**
         * 发送 post请求访问本地应用并根据传递参数不同返回不同结果
         */
        public void post() {
            // 创建默认的httpClient实例.
            CloseableHttpClient httpclient = HttpClients.createDefault();
            // 创建httppost
            HttpPost httppost = new HttpPost("http://localhost:8080/demo");
            // 创建参数队列
            List formparams = new ArrayList<>();
            formparams.add(new BasicNameValuePair("type", "house"));
            UrlEncodedFormEntity uefEntity;
            try {
                uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
                httppost.setEntity(uefEntity);
                System.out.println("executing request " + httppost.getURI());
                CloseableHttpResponse response = httpclient.execute(httppost);
                try {
                    HttpEntity entity = response.getEntity();
                    if (entity != null) {
                        System.out.println("--------------------------------------");
                        System.out.println("Response content: " + EntityUtils.toString(entity, "UTF-8"));
                        System.out.println("--------------------------------------");
                    }
                } finally {
                    response.close();
                }
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (UnsupportedEncodingException e1) {
                e1.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                // 关闭连接,释放资源
                try {
                    httpclient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    
        /**
         * 发送 get请求
         */
        public void get() {
            CloseableHttpClient httpclient = HttpClients.createDefault();
            try {
                // 创建httpget.
                HttpGet httpget = new HttpGet("https://www.baidu.com");
                System.out.println("executing request " + httpget.getURI());
                // 执行get请求.
                CloseableHttpResponse response = httpclient.execute(httpget);
                try {
                    // 获取响应实体
                    HttpEntity entity = response.getEntity();
                    System.out.println("--------------------------------------");
                    // 打印响应状态
                    System.out.println(response.getStatusLine());
                    if (entity != null) {
                        // 打印响应内容长度
                        System.out.println("Response content length: " + entity.getContentLength());
                        // 打印响应内容
                        System.out.println("Response content: " + EntityUtils.toString(entity));
                    }
                    System.out.println("------------------------------------");
                } finally {
                    response.close();
                }
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (ParseException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                // 关闭连接,释放资源
                try {
                    httpclient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    
        public String doHttpGet() {
            // 需要访问的接口路径
            String url = "https://www.baidu.com";
            // 配置请求信息（请求时间）
            RequestConfig rc = RequestConfig.custom().setSocketTimeout(5000)
                    .setConnectTimeout(5000).build();
            // 获取使用DefaultHttpClient对象
            CloseableHttpClient httpclient = HttpClients.createDefault();
            // 返回结果
            String result = null;
            try {
                if (url != null) {
                    // 创建HttpGet对象，将URL通过构造方法传入HttpGet对象
                    HttpGet httpget = new HttpGet(url);
                    // 将配置好请求信息附加到http请求中
                    httpget.setConfig(rc);
                    // 执行DefaultHttpClient对象的execute方法发送GET请求，通过CloseableHttpResponse接口的实例，可以获取服务器返回的信息
                    CloseableHttpResponse response = httpclient.execute(httpget);
                    try {
                        // 得到返回对象
                        HttpEntity entity = response.getEntity();
                        if (entity != null) {
                            // 获取返回结果
                            result = EntityUtils.toString(entity);
                        }
                    } finally {
                        // 关闭到客户端的连接
                        response.close();
                    }
                }
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    // 关闭http请求
                    httpclient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return result;
        }
    
        public static void main(String[] args) {
            HttpClient httpClient=new HttpClient();
            httpClient.get();
    
            String str=httpClient.doHttpGet();
            System.out.println(str);
    
        }
    }

要引入jar包

<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.5</version>
    </dependency>