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How to send HTTP request using Java HttpClient

王林
Release： 2023-04-20 23:49:09
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1. Import dependencies

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.3</version>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.58</version>
</dependency>

 <dependency>
     <groupId>org.apache.httpcomponents</groupId>
     <artifactId>httpmime</artifactId>
     <version>4.5.3</version>
 </dependency>

 <dependency>
     <groupId>org.apache.httpcomponents</groupId>
     <artifactId>httpcore</artifactId>
     <version>4.4.13</version>
 </dependency>
 
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.7</version>
</dependency>
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2. Use tool class

This tool class has written several parameter passing methods for get request and post request, including get address bar transmission Parameters, get's params parameters, post's params parameters, post's json parameters. 

import com.alibaba.fastjson.JSONObject;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
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.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntityBuilder;
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 org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class HttpClientUtil {

    private static Logger logger = LoggerFactory.getLogger(HttpClientUtil.class);

    private static final int DEFULT_TIMEOUT = 30 * 1000;//默认超时时间20秒

    /**
     * 可以访问  http://localhost:9005/yzhwsj/addPersonal/1/2 这样的接口
     * @param url
     * @param headers
     * @param urlParam
     * @param timeout
     * @return
     */
    private static String doUrlGet(String url, Map<String, String> headers, List<String> urlParam, Integer timeout) {
        //创建httpClient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        String resultString = null;
        CloseableHttpResponse response = null;
        try {
            //创建uri
            if (urlParam != null){
                for (String param : urlParam) {
                    url = url + "/" + param;
                }
            }
            //创建hTTP get请求
            HttpGet httpGet = new HttpGet(url);
            //设置超时时间
            int timeoutTmp = DEFULT_TIMEOUT;
            if (timeout != null) {
                timeoutTmp = timeout;
            }
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
                    .setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
            httpGet.setConfig(requestConfig);
            //设置头信息
            if (null != headers) {
                for (String key : headers.keySet()) {
                    httpGet.setHeader(key, headers.get(key));
                }
            }
            //执行请求
            response = httpClient.execute(httpGet);
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {
                resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
            }
        } catch (IOException e) {
            logger.error("http调用异常" + e.toString(), e);
        } finally {
            try {
                if (null != response) {
                    response.close();
                }
            } catch (IOException e) {
                logger.error("response关闭异常" + e.toString(), e);
            }
            try {
                if (null != httpClient) {
                    httpClient.close();
                }
            } catch (IOException e) {
                logger.error("httpClient关闭异常" + e.toString(), e);
            }
        }
        return resultString;
    }

    /**
     * @param url
     * @param headers
     * @param params
     * @param timeout
     * @return
     */
    private static String doGet(String url, Map<String, String> headers, Map<String, Object> params, Integer timeout) {
        //创建httpClient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        String resultString = null;
        CloseableHttpResponse response = null;
        try {
            // 1.创建uri
            URIBuilder builder = new URIBuilder(url);
            if (params != null) {
                //uri添加参数
                for (String key : params.keySet()) {
                    builder.addParameter(key, String.valueOf(params.get(key)));
                }
            }
            URI uri = builder.build();
            // 2.创建hTTP get请求
            HttpGet httpGet = new HttpGet(uri);
            // 3.设置超时时间
            int timeoutTmp = DEFULT_TIMEOUT;
            if (timeout != null) {
                timeoutTmp = timeout;
            }
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
                    .setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
            httpGet.setConfig(requestConfig);
            // 4.设置头信息
            if (null != headers) {
                for (String key : headers.keySet()) {
                    httpGet.setHeader(key, headers.get(key));
                }
            }
            // 5.执行请求
            response = httpClient.execute(httpGet);
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {
                resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
            }
        } catch (URISyntaxException e) {
            logger.error("http调用异常" + e.toString(), e);
        } catch (IOException e) {
            logger.error("http调用异常" + e.toString(), e);

        } finally {
            try {
                if (null != response) {
                    response.close();
                }
            } catch (IOException e) {
                logger.error("response关闭异常" + e.toString(), e);
            }
            try {
                if (null != httpClient) {
                    httpClient.close();
                }
            } catch (IOException e) {
                logger.error("httpClient关闭异常" + e.toString(), e);
            }
        }
        return resultString;
    }

    /**
     * 调用http post请求（json数据）
     *
     * @param url
     * @param headers
     * @param json
     * @return
     */
    public static String doJsonPost(String url, Map<String, String> headers, JSONObject json, Integer timeout) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 1.创建http post请求
            HttpPost httpPost = new HttpPost(url);
            // 2.设置超时时间
            int timeoutTmp = DEFULT_TIMEOUT;
            if (timeout != null) {
                timeoutTmp = timeout;
            }
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
                    .setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
            httpPost.setConfig(requestConfig);
            // 3.设置参数信息
            StringEntity s = new StringEntity(json.toString(), Consts.UTF_8);
            // 发送json数据需要设置的contentType
            s.setContentType("application/json");
            httpPost.setEntity(s);
            // 4.设置头信息
            if (headers != null) {
                for (String key : headers.keySet()) {
                    httpPost.setHeader(key, headers.get(key));
                }
            }
            // 5.执行http请求
            response = httpClient.execute(httpPost);
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
            }
        } catch (UnsupportedEncodingException e) {
            logger.error("调用http异常" + e.toString(), e);
        } catch (ClientProtocolException e) {
            logger.error("调用http异常" + e.toString(), e);
        } catch (IOException e) {
            logger.error("调用http异常" + e.toString(), e);
        } finally {
            try {
                if (null != response) {
                    response.close();
                }
            } catch (IOException e) {
                logger.error("关闭response异常" + e.toString(), e);
            }
            try {
                if (null != httpClient) {
                    httpClient.close();
                }
            } catch (IOException e) {
                logger.error("关闭httpClient异常" + e.toString(), e);
            }
        }
        return resultString;
    }

    /**
     * 调用http post请求 基础方法
     *
     * @param url     请求的url
     * @param headers 请求头
     * @param params  参数
     * @param timeout 超时时间
     * @return
     */
    public static String doPost(String url, Map<String, String> headers, Map<String, Object> params, Integer timeout) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 1.创建http post请求
            HttpPost httpPost = new HttpPost(url);
            // 2.设置超时时间
            int timeoutTmp = DEFULT_TIMEOUT;
            if (timeout != null) {
                timeoutTmp = timeout;
            }
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
                    .setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
            httpPost.setConfig(requestConfig);
            // 3.设置参数信息
            if (params != null) {
                List<NameValuePair> paramList = new ArrayList<>();
                for (String key : params.keySet()) {
                    paramList.add(new BasicNameValuePair(key, String.valueOf(params.get(key))));
                }
                // 模拟表单
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList, Consts.UTF_8);
                httpPost.setEntity(entity);
            }
            // 4.设置头信息
            if (headers != null) {
                for (String key : headers.keySet()) {
                    httpPost.setHeader(key, headers.get(key));
                }
            }
            // 5.执行http请求
            response = httpClient.execute(httpPost);
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
            }
        } catch (UnsupportedEncodingException e) {
            logger.error("调用http异常" + e.toString(), e);
        } catch (ClientProtocolException e) {
            logger.error("调用http异常" + e.toString(), e);
        } catch (IOException e) {
            logger.error("调用http异常" + e.toString(), e);
        } finally {
            try {
                if (null != response) {
                    response.close();
                }
            } catch (IOException e) {
                logger.error("关闭response异常" + e.toString(), e);
            }
            try {
                if (null != httpClient) {
                    httpClient.close();
                }
            } catch (IOException e) {
                logger.error("关闭httpClient异常" + e.toString(), e);
            }
        }
        return resultString;
    }
    
	/**
     * 通过httpClient上传文件
     *
     * @param url      请求的URL
     * @param headers  请求头参数
     * @param path     文件路径
     * @param fileName 文件名称
     * @param timeout  超时时间
     * @return
     */
    public static String UploadFileByHttpClient(String url, Map<String, String> headers, String path, String fileName, Integer timeout) {
        String resultString = "";
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        InputStream content = null;
        BufferedReader in = null;
        try {
            // 1.创建http post请求
            HttpPost httpPost = new HttpPost(url);

            // 2.设置超时时间
            int timeoutTmp = DEFULT_TIMEOUT;
            if (timeout != null) {
                timeoutTmp = timeout;
            }
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
                    .setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
            httpPost.setConfig(requestConfig);

            // 3.设置参数信息
            // HttpMultipartMode.RFC6532参数的设定是为避免文件名为中文时乱码
            MultipartEntityBuilder builder = MultipartEntityBuilder.create().setMode(HttpMultipartMode.RFC6532);
            // 上传文件的路径
            File file = new File(path + File.separator + fileName);
            builder.setCharset(Charset.forName("UTF-8"));
            builder.addBinaryBody("file", file, ContentType.MULTIPART_FORM_DATA, fileName);
            HttpEntity entity = builder.build();
            httpPost.setEntity(entity);

            // 4.设置头信息
            if (headers != null) {
                for (String key : headers.keySet()) {
                    httpPost.setHeader(key, headers.get(key));
                }
            }

            // 5.执行http请求
            response = httpClient.execute(httpPost);
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
            }
        } catch (Exception e) {
            logger.error("上传文件失败：", e);
        } finally {
            try {
                if (null != httpClient) {
                    httpClient.close();
                }
            } catch (IOException e) {
                logger.error("关闭httpClient异常" + e.toString(), e);
            }
            try {
                if (null != content) {
                    content.close();
                }
            } catch (IOException e) {
                logger.error("关闭content异常" + e.toString(), e);
            }
            try {
                if (null != in) {
                    in.close();
                }
            } catch (IOException e) {
                logger.error("关闭in异常" + e.toString(), e);
            }
        }

        return resultString;
    }
 }

	/**
     * 通过httpClient批量上传文件
     *
     * @param url     请求的URL
     * @param headers 请求头参数
     * @param params  参数
     * @param paths   文件路径(key文件名称，value路径)
     * @param timeout 超时时间
     * @return
     */
    public static String UploadFilesByHttpClient(String url, Map<String, String> headers, Map<String, String> params, Map<String, String> paths, Integer timeout) {
        String resultString = "";
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        InputStream content = null;
        BufferedReader in = null;
        try {
            // 1.创建http post请求
            HttpPost httpPost = new HttpPost(url);

            // 2.设置超时时间
            int timeoutTmp = DEFULT_TIMEOUT;
            if (timeout != null) {
                timeoutTmp = timeout;
            }
            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
                    .setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
            httpPost.setConfig(requestConfig);

            // 3.设置文件信息
            // HttpMultipartMode.RFC6532参数的设定是为避免文件名为中文时乱码
            MultipartEntityBuilder builder = MultipartEntityBuilder.create().setMode(HttpMultipartMode.RFC6532);
            builder.setCharset(Charset.forName("UTF-8"));
            // 上传文件的路径
            for (Map.Entry<String, String> m : paths.entrySet()) {
                File file = new File(m.getValue() + File.separator + m.getKey());
                builder.addBinaryBody("files", file, ContentType.MULTIPART_FORM_DATA, m.getKey());
            }

            // 4.设置参数信息
            ContentType contentType = ContentType.create("text/plain", Charset.forName("UTF-8"));
            for (Map.Entry<String, String> param : params.entrySet()) {
                builder.addTextBody(param.getKey(), param.getValue(), contentType);
            }
            HttpEntity entity = builder.build();
            httpPost.setEntity(entity);

            // 5.设置头信息
            if (headers != null) {
                for (String key : headers.keySet()) {
                    httpPost.setHeader(key, headers.get(key));
                }
            }

            // 6.执行http请求
            response = httpClient.execute(httpPost);
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
            }
        } catch (Exception e) {
            logger.error("上传文件失败：", e);
        } finally {
            try {
                if (null != httpClient) {
                    httpClient.close();
                }
            } catch (IOException e) {
                logger.error("关闭httpClient异常" + e.toString(), e);
            }
            try {
                if (null != content) {
                    content.close();
                }
            } catch (IOException e) {
                logger.error("关闭content异常" + e.toString(), e);
            }
            try {
                if (null != in) {
                    in.close();
                }
            } catch (IOException e) {
                logger.error("关闭in异常" + e.toString(), e);
            }
        }

        return resultString;
    }
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3. Extend the tool class above

. All methods carry token and timeout. If the interface is not used, you can expand the interface. For example: 

/**
 * 调用http get请求
 *
 * @param url
 * @param params
 * @return
 */
public static String doGet(String url, Map<String, Object> params) {
    return doGet(url, null, params, null);
}
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If it involves put requests and delete requests, it is similar to the above, except when creating the request, it is changed to: 

HttpDelete httpDelete = new HttpDelete();

HttpPut httpPut = new HttpPut();
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Related labels：
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source：yisu.com
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