Java实现HttpClient发送GET、POST请求（https、http）

朴灿烈づ我的快乐病毒、 2021-09-28 22:06 1564阅读 0赞

# 1、引入相关依赖包 #

jar包下载：[httpcore4.5.5.jar][]    [fastjson-1.2.47.jar][]

maven：

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<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.5</version>
    </dependency>
    
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.47</version>
    </dependency>

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# 2、主要类HttpClientService #

![复制代码][copycode.gif]

1 package com.sinotn.service;
      2 
      3 import com.alibaba.fastjson.JSONObject;
      4 import org.apache.http.HttpEntity;
      5 import org.apache.http.NameValuePair;
      6 import org.apache.http.client.entity.UrlEncodedFormEntity;
      7 import org.apache.http.client.methods.CloseableHttpResponse;
      8 import org.apache.http.client.methods.HttpGet;
      9 import org.apache.http.client.methods.HttpPost;
     10 import org.apache.http.client.utils.URIBuilder;
     11 import org.apache.http.entity.StringEntity;
     12 import org.apache.http.impl.client.CloseableHttpClient;
     13 import org.apache.http.impl.client.HttpClients;
     14 import org.apache.http.message.BasicHeader;
     15 import org.apache.http.message.BasicNameValuePair;
     16 import org.apache.http.util.EntityUtils;
     17 import org.slf4j.Logger;
     18 import org.slf4j.LoggerFactory;
     19 import java.util.ArrayList;
     20 import java.util.List;
     21 
     22 /**
     23  * HttpClient发送GET、POST请求
     24  * @Author libin
     25  * @CreateDate 2018.5.28 16:56
     26  */
     27 public class HttpClientService {
     28 
     29     private static final Logger LOGGER = LoggerFactory.getLogger(HttpClientService.class);
     30     /**
     31      * 返回成功状态码
     32      */
     33     private static final int SUCCESS_CODE = 200;
     34 
     35     /**
     36      * 发送GET请求
     37      * @param url   请求url
     38      * @param nameValuePairList    请求参数
     39      * @return JSON或者字符串
     40      * @throws Exception
     41      */
     42     public static Object sendGet(String url, List<NameValuePair> nameValuePairList) throws Exception{
     43         JSONObject jsonObject = null;
     44         CloseableHttpClient client = null;
     45         CloseableHttpResponse response = null;
     46         try{
     47             /**
     48              * 创建HttpClient对象
     49              */
     50             client = HttpClients.createDefault();
     51             /**
     52              * 创建URIBuilder
     53              */
     54             URIBuilder uriBuilder = new URIBuilder(url);
     55             /**
     56              * 设置参数
     57              */
     58             uriBuilder.addParameters(nameValuePairList);
     59             /**
     60              * 创建HttpGet
     61              */
     62             HttpGet httpGet = new HttpGet(uriBuilder.build());
     63             /**
     64              * 设置请求头部编码
     65              */
     66             httpGet.setHeader(new BasicHeader("Content-Type", "application/x-www-form-urlencoded; charset=utf-8"));
     67             /**
     68              * 设置返回编码
     69              */
     70             httpGet.setHeader(new BasicHeader("Accept", "text/plain;charset=utf-8"));
     71             /**
     72              * 请求服务
     73              */
     74             response = client.execute(httpGet);
     75             /**
     76              * 获取响应吗
     77              */
     78             int statusCode = response.getStatusLine().getStatusCode();
     79 
     80             if (SUCCESS_CODE == statusCode){
     81                 /**
     82                  * 获取返回对象
     83                  */
     84                 HttpEntity entity = response.getEntity();
     85                 /**
     86                  * 通过EntityUitls获取返回内容
     87                  */
     88                 String result = EntityUtils.toString(entity,"UTF-8");
     89                 /**
     90                  * 转换成json,根据合法性返回json或者字符串
     91                  */
     92                 try{
     93                     jsonObject = JSONObject.parseObject(result);
     94                     return jsonObject;
     95                 }catch (Exception e){
     96                     return result;
     97                 }
     98             }else{
     99                 LOGGER.error("HttpClientService-line: {}, errorMsg{}", 97, "GET请求失败！");
    100             }
    101         }catch (Exception e){
    102             LOGGER.error("HttpClientService-line: {}, Exception: {}", 100, e);
    103         } finally {
    104             response.close();
    105             client.close();
    106         }
    107         return null;
    108     }
    109 
    110     /**
    111      * 发送POST请求
    112      * @param url
    113      * @param nameValuePairList
    114      * @return JSON或者字符串
    115      * @throws Exception
    116      */
    117     public static Object sendPost(String url, List<NameValuePair> nameValuePairList) throws Exception{
    118         JSONObject jsonObject = null;
    119         CloseableHttpClient client = null;
    120         CloseableHttpResponse response = null;
    121         try{
    122             /**
    123              *  创建一个httpclient对象
    124              */
    125             client = HttpClients.createDefault();
    126             /**
    127              * 创建一个post对象
    128              */
    129             HttpPost post = new HttpPost(url);
    130             /**
    131              * 包装成一个Entity对象
    132              */
    133             StringEntity entity = new UrlEncodedFormEntity(nameValuePairList, "UTF-8");
    134             /**
    135              * 设置请求的内容
    136              */
    137             post.setEntity(entity);
    138             /**
    139              * 设置请求的报文头部的编码
    140              */
    141             post.setHeader(new BasicHeader("Content-Type", "application/x-www-form-urlencoded; charset=utf-8"));
    142             /**
    143              * 设置请求的报文头部的编码
    144              */
    145             post.setHeader(new BasicHeader("Accept", "text/plain;charset=utf-8"));
    146             /**
    147              * 执行post请求
    148              */
    149             response = client.execute(post);
    150             /**
    151              * 获取响应码
    152              */
    153             int statusCode = response.getStatusLine().getStatusCode();
    154             if (SUCCESS_CODE == statusCode){
    155                 /**
    156                  * 通过EntityUitls获取返回内容
    157                  */
    158                 String result = EntityUtils.toString(response.getEntity(),"UTF-8");
    159                 /**
    160                  * 转换成json,根据合法性返回json或者字符串
    161                  */
    162                 try{
    163                     jsonObject = JSONObject.parseObject(result);
    164                     return jsonObject;
    165                 }catch (Exception e){
    166                     return result;
    167                 }
    168             }else{
    169                 LOGGER.error("HttpClientService-line: {}, errorMsg：{}", 146, "POST请求失败！");
    170             }
    171         }catch (Exception e){
    172             LOGGER.error("HttpClientService-line: {}, Exception：{}", 149, e);
    173         }finally {
    174             response.close();
    175             client.close();
    176         }
    177         return null;
    178     }
    179 
    180     /**
    181      * 组织请求参数{参数名和参数值下标保持一致}
    182      * @param params    参数名数组
    183      * @param values    参数值数组
    184      * @return 参数对象
    185      */
    186     public static List<NameValuePair> getParams(Object[] params, Object[] values){
    187         /**
    188          * 校验参数合法性
    189          */
    190         boolean flag = params.length>0 && values.length>0 &&  params.length == values.length;
    191         if (flag){
    192             List<NameValuePair> nameValuePairList = new ArrayList<>();
    193             for(int i =0; i<params.length; i++){
    194                 nameValuePairList.add(new BasicNameValuePair(params[i].toString(),values[i].toString()));
    195             }
    196             return nameValuePairList;
    197         }else{
    198             LOGGER.error("HttpClientService-line: {}, errorMsg：{}", 197, "请求参数为空且参数长度不一致");
    199         }
    200         return null;
    201     }
    202 }

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# 3、调用方法 #

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1 package com.sinotn.service.impl;
     2 
     3 import com.sinotn.service.HttpClientService;
     4 import org.apache.http.NameValuePair;
     5 
     6 import java.util.List;
     7 
     8 /**
     9  * 发送post/get 测试类
    10  */
    11 public class Test {
    12 
    13     public static void main(String[] args) throws Exception{
    14         String url = "要请求的url地址";
    15         /**
    16          * 参数值
    17          */
    18         Object [] params = new Object[]{"param1","param2"};
    19         /**
    20          * 参数名
    21          */
    22         Object [] values = new Object[]{"value1","value2"};
    23         /**
    24          * 获取参数对象
    25          */
    26         List<NameValuePair> paramsList = HttpClientService.getParams(params, values);
    27         /**
    28          * 发送get
    29          */
    30         Object result = HttpClientService.sendGet(url, paramsList);
    31         /**
    32          * 发送post
    33          */
    34         Object result2 = HttpClientService.sendPost(url, paramsList);
    35 
    36         System.out.println("GET返回信息：" + result);
    37         System.out.println("POST返回信息：" + result2);
    38     }
    39 }

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# 4、对于发送https #

为了避免需要证书，所以用一个类继承DefaultHttpClient类，忽略校验过程。

写一个SSLClient类，继承至HttpClient

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1 import java.security.cert.CertificateException;
     2 import java.security.cert.X509Certificate;
     3 import javax.net.ssl.SSLContext;
     4 import javax.net.ssl.TrustManager;
     5 import javax.net.ssl.X509TrustManager;
     6 import org.apache.http.conn.ClientConnectionManager;
     7 import org.apache.http.conn.scheme.Scheme;
     8 import org.apache.http.conn.scheme.SchemeRegistry;
     9 import org.apache.http.conn.ssl.SSLSocketFactory;
    10 import org.apache.http.impl.client.DefaultHttpClient;
    11 //用于进行Https请求的HttpClient
    12 public class SSLClient extends DefaultHttpClient{
    13     public SSLClient() throws Exception{
    14         super();
    15         SSLContext ctx = SSLContext.getInstance("TLS");
    16         X509TrustManager tm = new X509TrustManager() {
    17                 @Override
    18                 public void checkClientTrusted(X509Certificate[] chain,
    19                         String authType) throws CertificateException {
    20                 }
    21                 @Override
    22                 public void checkServerTrusted(X509Certificate[] chain,
    23                         String authType) throws CertificateException {
    24                 }
    25                 @Override
    26                 public X509Certificate[] getAcceptedIssuers() {
    27                     return null;
    28                 }
    29         };
    30         ctx.init(null, new TrustManager[]{tm}, null);
    31         SSLSocketFactory ssf = new SSLSocketFactory(ctx,SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
    32         ClientConnectionManager ccm = this.getConnectionManager();
    33         SchemeRegistry sr = ccm.getSchemeRegistry();
    34         sr.register(new Scheme("https", 443, ssf));
    35     }
    36 }

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# 5、对于https调用 #

![1165001-20180601134234180-703438592.png][]

转载自：[https://www.cnblogs.com/klslb/p/9121276.html][https_www.cnblogs.com_klslb_p_9121276.html]

[httpcore4.5.5.jar]: http://central.maven.org/maven2/org/apache/httpcomponents/httpclient/4.5.5/httpclient-4.5.5.jar
[fastjson-1.2.47.jar]: http://central.maven.org/maven2/com/alibaba/fastjson/1.2.47/fastjson-1.2.47.jar
[copycode.gif]: /images/20210923/c4ee74a3c2c34242ac19b0c09d81c8aa.png
[1165001-20180601134234180-703438592.png]: /images/20210923/6739be58356a418c95ab94ea4df14b6f.png
[https_www.cnblogs.com_klslb_p_9121276.html]: https://www.cnblogs.com/klslb/p/9121276.html