java使用httpclient 發(fā)送請(qǐng)求的示例

更新時(shí)間：2023年10月19日 11:54:23 作者：有夢(mèng)想的菜

HttpClient 是Apache Jakarta Common 下的子項(xiàng)目,可以用來提供高效的、最新的、功能豐富的支持 HTTP 協(xié)議的客戶端編程工具包,并且它支持 HTTP 協(xié)議最新的版本和建議,這篇文章主要介紹了java使用httpclient 發(fā)送請(qǐng)求的示例,需要的朋友可以參考下

一、使用的Jar包

首先需要在maven中引入如下包

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpclient</artifactId>
  <version>4.5.13</version>
</dependency>
<dependency>
  <groupId>com.alibaba</groupId>
  <artifactId>fastjson</artifactId>
  <version>2.0.18</version>
</dependency>

二、接口代碼

Get的無參/有參請(qǐng)求

/**
 * @param url     接口地址
 * @param headers 請(qǐng)求頭
 * @Description get請(qǐng)求
 */
public static String getData(String url, Map<String, String> headers) {
    String StringResult = "";
    CloseableHttpClient closeableHttpClient = HttpClients.createDefault();
    HttpGet httpGet = new HttpGet(url);
    if (headers != null && !headers.isEmpty()) {
        for (String head : headers.keySet()) {
            httpGet.addHeader(head, headers.get(head));
        }
    }
    CloseableHttpResponse response = null;
    try {
        response = closeableHttpClient.execute(httpGet);
        HttpEntity entity = response.getEntity();
        StringResult = EntityUtils.toString(entity, StandardCharsets.UTF_8).trim();
        EntityUtils.consume(entity);
    } catch (Exception e) {
        e.printStackTrace();
        StringResult = "errorException:" + e.getMessage();
    } finally {
        if (response != null) {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (closeableHttpClient != null) {
            try {
                closeableHttpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return StringResult;
}

請(qǐng)求實(shí)列：在這里無參請(qǐng)求就不展示，可自行試驗(yàn)

Map<String, String> headers = new HashMap<>();
headers.put("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36");
String data = getData("https://api.vvhan.com/api/covid?city=重慶", headers);
System.out.println(data);

請(qǐng)求結(jié)果：

{
"success": true,
"data": {
"updatetime": "2022-12-23 09:46:10",
"country": "中國",
"province": "重慶",
"city": "重慶",
"now": {
"sure_new_loc": "未公布",
"sure_new_hid": "未公布",
"sure_present": 3108
},
"history": {
"sure_cnt": 10452,
"cure_cnt": 7337,
"die_cnt": 7
},
"danger": {
"high_risk": 0,
"medium_risk": 0
}
}
}

Post請(qǐng)求（application/x-www-form-urlencoded）

/**
 * @param url     接口地址
 * @param list    NameValuePair（簡(jiǎn)單名稱值對(duì)節(jié)點(diǎn)類型）類似html中的input
 * @param headers 請(qǐng)求頭（默認(rèn)Content-Type：application/x-www-form-urlencoded; charset=UTF-8）
 * @Description post請(qǐng)求
 */
public static String postData(String url, ArrayList<NameValuePair> list, Map<String, String> headers) {
    String StringResult = "";
    CloseableHttpClient closeableHttpClient = HttpClients.createDefault();
    HttpPost httpPost = new HttpPost(url);
    if (list != null && !list.isEmpty()) {
        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(list, Consts.UTF_8);
        httpPost.setEntity(formEntity);
    }
    httpPost.addHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
    if (headers != null && !headers.isEmpty()) {
        for (String head : headers.keySet()) {
            httpPost.addHeader(head, headers.get(head));
        }
    }
    CloseableHttpResponse response = null;
    try {
        response = closeableHttpClient.execute(httpPost);
        HttpEntity entity = response.getEntity();
        StringResult = EntityUtils.toString(entity, StandardCharsets.UTF_8);
        EntityUtils.consume(entity);
    } catch (Exception e) {
        StringResult = "errorException:" + e.getMessage();
        e.printStackTrace();
    } finally {
        if (response != null) {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (closeableHttpClient != null) {
            try {
                closeableHttpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return StringResult;
}

請(qǐng)求實(shí)列：

ArrayList<NameValuePair> list = new ArrayList<>();
list.add(new BasicNameValuePair("username", "用戶名"));
list.add(new BasicNameValuePair("password", "1234"));
String s = postData("http://127.0.0.1:3000/aaa/file/testPost.jsp", list, null);
System.out.println(s);

請(qǐng)求結(jié)果：

用戶名
1234
application/x-www-form-urlencoded; charset=UTF-8

Post請(qǐng)求（application/json）

/**
 * @param url        接口地址
 * @param jsonString json字符串
 * @param headers    請(qǐng)求頭(默認(rèn)Content-Type：application/json; charset=UTF-8)
 * @Description post Json 請(qǐng)求
 */
public static String postJsonData(String url, @NotNull String jsonString, Map<String, String> headers) {
    String StringResult = "";
    CloseableHttpClient closeableHttpClient = HttpClients.createDefault();
    HttpPost httpPost = new HttpPost(url);
    StringEntity jsonEntity = new StringEntity(jsonString, Consts.UTF_8);
    jsonEntity.setContentEncoding(Consts.UTF_8.name());
    httpPost.setEntity(jsonEntity);
    httpPost.addHeader("Content-Type", "application/json; charset=UTF-8");
    if (headers != null && !headers.isEmpty()) {
        for (String head : headers.keySet()) {
            httpPost.addHeader(head, headers.get(head));
        }
    }
    CloseableHttpResponse response = null;
    try {
        response = closeableHttpClient.execute(httpPost);
        HttpEntity entity = response.getEntity();
        StringResult = EntityUtils.toString(entity, StandardCharsets.UTF_8);
        EntityUtils.consume(entity);
    } catch (Exception e) {
        StringResult = "errorException:" + e.getMessage();
        e.printStackTrace();
    } finally {
        if (response != null) {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (closeableHttpClient != null) {
            try {
                closeableHttpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return StringResult;
}

請(qǐng)求實(shí)列：

JSONObject jsonObject = new JSONObject();
jsonObject.put("demo", "456789");
jsonObject.put("demo1", "哈哈哈愛發(fā)火");
String s = postJsonData("http://127.0.0.1:3000/api/workflow/v1/insert2", jsonObject.toJSONString(), null);
System.out.println(s);

請(qǐng)求結(jié)果：

Get請(qǐng)求url拼接

/**
 * @param url    接口地址(無參數(shù)/有參)
 * @param params 拼接參數(shù)集合
 * @Description get請(qǐng)求URL拼接參數(shù) & URL編碼
 */
public static String getAppendUrl(String url, Map<String, String> params) {
    StringBuffer buffer = new StringBuffer(url);
    if (params != null && !params.isEmpty()) {
        for (String key : params.keySet()) {
            if (buffer.indexOf("?") >= 0) {
                buffer.append("&");
            } else {
                buffer.append("?");
            }
            String value = "";
            try {
                value = URLEncoder.encode(params.get(key), StandardCharsets.UTF_8.name());
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            buffer.append(key)
                    .append("=")
                    .append(value);
        }
    }
    return buffer.toString();
}

請(qǐng)求實(shí)列：

Map<String, String> params = new HashMap<>();
params.put("city", "重慶");
params.put("number", "手機(jī)號(hào)");
String appendUrl = getAppendUrl("https://TestGetSplice/index", params);
String appendUrl1 = getAppendUrl("https://TestGetSplice/index?a=33", params);
System.out.println(appendUrl);
System.out.println(appendUrl1);

請(qǐng)求結(jié)果：

https://TestGetSplice/index?number=%E6%89%8B%E6%9C%BA%E5%8F%B7&city=%E9%87%8D%E5%BA%86
https://TestGetSplice/index?a=33&number=%E6%89%8B%E6%9C%BA%E5%8F%B7&city=%E9%87%8D%E5%BA%86

三、使用的類

import com.alibaba.fastjson.JSONObject;
import com.sun.istack.internal.NotNull;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
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.entity.StringEntity;
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.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

四、標(biāo)準(zhǔn)字符集的常量定義

這些字符集保證在Java平臺(tái)的每個(gè)實(shí)現(xiàn)上都可用。

import java.nio.charset.StandardCharsets;
StandardCharsets.UTF_8

五、請(qǐng)求狀態(tài)常量

import org.apache.http.HttpStatus;
// 200
HttpStatus.SC_OK

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