Java HttpClient怎么使用

今天小编给大家分享一下Java HttpClient怎么使用的相关知识点，内容详细，逻辑清晰，相信大部分人都还太了解这方面的知识，所以分享这篇文章给大家参考一下，希望大家阅读完这篇文章后有所收获，下面我们一起来了解一下吧。

1、导入依赖

<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>

2、使用工具类

该工具类将get请求和post请求当中几种传参方式都写了，其中有get地址栏传参、get的params传参、post的params传参、post的json传参。

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        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;    }        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;    }        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;    }        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;    }        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;    } }    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;    }

3、扩展

上面的工具类，方法都携带了token和超时时间，假如接口用不到可以做接口拓展。例如：

public static String doGet(String url, Map<String, Object> params) {    return doGet(url, null, params, null);}

如果涉及到put请求和delete请求，跟上面都差不多，只不过创建请求的时候改为:

HttpDelete httpDelete = new HttpDelete();HttpPut httpPut = new HttpPut();

以上就是“Java HttpClient怎么使用”这篇文章的所有内容，感谢各位的阅读！相信大家阅读完这篇文章都有很大的收获，小编每天都会为大家更新不同的知识，如果还想学习更多的知识，请关注编程网行业资讯频道。