java httpclient调用接口

1. 需要引入依赖

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version>
</dependency>

2. 使用案例

import org.apache.commons.lang3.exception.ExceptionUtils;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.config.RequestConfig;
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.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.protocol.HTTP;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.net.URI;
import java.nio.charset.Charset;

public class UseHttpclientDemo {
    public static void main(String[] args) {
        String postResultData = postResult();
        if (postResultData == null) {
            System.out.println("{\"errno\":-1,\"errmsg\":\"fail\",\"message\":\"调用接口获取数据失败\"}");
            return;
        }
        System.out.println(postResultData);

        String getResultData = getResult();
        if (getResultData == null) {
            System.out.println("{\"errno\":-1,\"errmsg\":\"fail\",\"message\":\"调用接口获取数据失败\"}");
            return;
        }
        System.out.println(getResultData);
    }

    public static String postResult() {
        //超时时间
        /**
         * RequestConfig.DEFAULT == 一直请求
         * RequestConfig.DEFAULT == RequestConfig.custom()
         *          .setConnectTimeout(-1).setConnectionRequestTimeout(-1).setSocketTimeout(-1)
         *          .build();
         */
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(3000) //连接主机超时时间
                .setConnectionRequestTimeout(4000) //请求超时时间
                .setSocketTimeout(5000) //数据读取超时时间
                .build();
        //请求体
        StringEntity requestBody = new StringEntity("{\"invoke_info\":{\"pos_1\":[{}],\"pos_2\":[{}],\"pos_3\":[{}]}}", ContentType.APPLICATION_JSON);


        //http客户端
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //post请求
        HttpPost postRequest = new HttpPost();
        postRequest.setConfig(requestConfig);
        postRequest.setURI(URI.create("https://ug.baidu.com/mcp/pc/pcsearch")); //请求路径
        postRequest.addHeader(HTTP.CONTENT_TYPE, ContentType.APPLICATION_JSON.toString()); //请求头
        postRequest.addHeader("xxx","xxx");
        postRequest.addHeader("xxx","xxx");
        postRequest.setEntity(requestBody); //请求体
        String result = null;
        try {
            //发送请求
            CloseableHttpResponse response = httpClient.execute(postRequest);
            if (response == null || response.getStatusLine() == null || response.getStatusLine().getStatusCode() !=200) {
                return null;
            }
            /**
             * response.getHeaders("xxx"); //响应头
             * response.getEntity().getContent(); //响应体(获取文件数据)
             * EntityUtils.toString(response.getEntity(), Charset.defaultCharset()); //响应体(获取json数据)
             */
            //响应内容
            String responseBody = EntityUtils.toString(response.getEntity(), Charset.defaultCharset()); //响应体(获取json数据)
            result = responseBody;
        } catch (ClientProtocolException e) {
            //接口调用异常或接口数据传输异常
            System.out.println("接口调用异常:"+e);
            System.out.println(ExceptionUtils.getStackTrace(e));
        } catch (IOException e) {
            //接口数据传输异常
            System.out.println("接口调用异常："+e);
            System.out.println(ExceptionUtils.getStackTrace(e));
        } finally {
            if (httpClient != null) {
                try {
                    httpClient.close();
                } catch (IOException e) {
                    //关闭httpclient失败
                    System.out.println("关闭httpclient失败：");
                    System.out.println(ExceptionUtils.getStackTrace(e));
                }
            }
        }
        return result;
    }

    public static String getResult() {
        //超时时间
        /**
         * RequestConfig.DEFAULT == 一直请求
         * RequestConfig.DEFAULT == RequestConfig.custom()
         *          .setConnectTimeout(-1).setConnectionRequestTimeout(-1).setSocketTimeout(-1)
         *          .build();
         */
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(3000) //连接主机超时时间
                .setConnectionRequestTimeout(4000) //请求超时时间
                .setSocketTimeout(5000) //数据读取超时时间
                .build();

        //http客户端
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //post请求
        HttpGet getRequest = new HttpGet();
        getRequest.setConfig(requestConfig);
        getRequest.setURI(URI.create("https://dict.youdao.com/login/acc/query/accountinfo?withCredentials=true&caKu=3")); //请求路径+入参
        getRequest.addHeader(HTTP.CONTENT_TYPE, ContentType.APPLICATION_JSON.toString()); //请求头
        getRequest.addHeader("xxx","xxx");
        getRequest.addHeader("xxx","xxx");
        String result = null;
        try {
            //发送请求
            CloseableHttpResponse response = httpClient.execute(getRequest);
            if (response == null || response.getStatusLine() == null || response.getStatusLine().getStatusCode() !=200) {
                return null;
            }
            /**
             * response.getHeaders("xxx"); //响应头
             * response.getEntity().getContent(); //响应体(获取文件数据)
             * EntityUtils.toString(response.getEntity(), Charset.defaultCharset()); //响应体(获取json数据)
             */
            //响应内容
            String responseBody = EntityUtils.toString(response.getEntity(), Charset.defaultCharset()); //响应体(获取json数据)
            result = responseBody;
        } catch (ClientProtocolException e) {
            //接口调用异常或接口数据传输异常
            System.out.println("接口调用异常:"+e);
            System.out.println(ExceptionUtils.getStackTrace(e));
        } catch (IOException e) {
            //接口数据传输异常
            System.out.println("接口调用异常："+e);
            System.out.println(ExceptionUtils.getStackTrace(e));
        } finally {
            if (httpClient != null) {
                try {
                    httpClient.close();
                } catch (IOException e) {
                    //关闭httpclient失败
                    System.out.println("关闭httpclient失败：");
                    System.out.println(ExceptionUtils.getStackTrace(e));
                }
            }
        }
        return result;
    }
}