详解Java发送HTTP请求

前言

请求http的Demo是个人亲测过，目前该方式已经在线上运行着。因为是http请求，所有发送post 和get 请求的demo都有在下方贴出，包括怎么测试，大家可直接 copy到自己的项目中使用。

正文

使用须知

为了避免大家引错包我把依赖和涉及到包路径给大家

import java.net.HttpURLConnection;
import java.net.URI;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
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.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import com.fasterxml.jackson.databind.ObjectMapper;

<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.4.8</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.3</version>
</dependency>

HTTP 发送 get 请求

首先我们引入两个包

发送get请求的工具类，可直接 copy 使用即可

另外，我抛出异常的代码大家改成自己业务的异常，不需要就删除掉。

参数说明：

host：ip

servUri：url

reString：参数

public static String getHttpData(String host, String servUri, String reString) throws Exception {
StringBuffer sb = new StringBuffer();
sb.append("getHttpData:host:" + host + ",servUri:" + servUri + ",reString:" + reString);
String strResp = null;
try {
URI uri = new URIBuilder().setScheme("http").setHost(host).setPath(servUri)
.setParameter("strInfo", reString).build();
HttpGet httpGet = new HttpGet(uri);
CloseableHttpClient client3 = HttpClients.createDefault();
HttpResponse resp;
resp = client3.execute(httpGet);
if (resp.getStatusLine().getStatusCode() == HttpURLConnection.HTTP_OK) {
strResp = EntityUtils.toString(resp.getEntity());
logger.info("the return result:{}", strResp);
} else {
logger.info("Error Response:", resp.getStatusLine().toString());
throw new CommonBusinessException(CommonConstants.TASK_RELEASE_WCF,
CommonConstants.TASK_RELEASE_WCF_DESC);
}
} catch (Exception e) {
logger.error(sb.toString() + ":" + e.getMessage(), e.getCause());
throw new CommonBusinessException(CommonConstants.TASK_RELEASE_WCF, CommonConstants.TASK_RELEASE_WCF_DESC);
}
return strResp;
}
 

HTTP 发送 post 请求

发送post分两种,我分两种的原因是为了让大家方便，想传对象和 json 可以直接复制过用就可以用，不用你们在转了。

第一种是直接接收json

参数明说：

url：url

json：参数

public static String doPostData(String url, String json) throws Exception {
DefaultHttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
String result = "";
HttpResponse res = null;
try {
StringEntity s = new StringEntity(json.toString(), "UTF-8");
s.setContentType("application/json");
post.setHeader("Accept", "application/json");
post.setHeader("Content-type", "application/json; charset=utf-8");
post.setEntity(s);
res = client.execute(post);
if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
result = EntityUtils.toString(res.getEntity());
return HttpStatus.SC_OK + "";
}
} catch (Exception e) {
if(res == null) {
return "HttpResponse 为 null!";
}
throw new RuntimeException(e);
}
if(res == null || res.getStatusLine() == null) {
return "无响应";
}
return res.getStatusLine().getStatusCode() + "";
}

@Test
 public void test12() throws Exception {
   String HOST = "http://eipwcf.aspirecn.com/SvcEF/Service1.svc/WCF_EF_MSA_GetDataInfo_P";
   HttpClient client = new HttpClient();
   JSONObject json = new JSONObject();
   json.put("msgId", msgId);
   String reslut=client.doPostData(HOST, json);
 }
 

第二种是参数是对象

参数说明：

url：url

tram：对象

public static String doHttpPostData(String url, TaskReleaseApprovalModel tram)
throws Exception {
StringBuffer sb = new StringBuffer();
sb.append("doHttpPostData:url:" + url + ",tram:" + tram.toString() + ",contentType:" + contentType);
logger.info(sb.toString());
String tmpString = "";
HttpPost request = new HttpPost(url);
request.setHeader("Accept", "application/json");
request.setHeader("Content-type", "application/json");
ObjectMapper mapper = new ObjectMapper();
String jsonString;
try {
jsonString = mapper.writeValueAsString(tram);
StringEntity entity = new StringEntity(jsonString, "UTF-8");
request.setEntity(entity);
CloseableHttpClient client = HttpClients.createDefault();
HttpResponse response = client.execute(request);
if (response.getStatusLine().getStatusCode() == HttpURLConnection.HTTP_OK) {
tmpString = EntityUtils.toString(response.getEntity());
logger.info("the post result:tmpString:{}", tmpString);
} else {
logger.info("the post failure:tmpString:", tmpString);
throw new CommonBusinessException(CommonConstants.TASK_RELEASE_WCF,
CommonConstants.TASK_RELEASE_WCF_DESC);
}
} catch (Exception e) {
logger.error(sb.toString() + ":" + e.getMessage(), e.getCause());
throw new CommonBusinessException(CommonConstants.TASK_RELEASE_POSTWCF,
CommonConstants.TASK_RELEASE_POSTWCF_DESC);
}
return tmpString;
}

这个方法我想不用写测试类大家也会用，传过去对象和地址就可以了，很方便很简单。

以上所述是小编给大家介绍的Java发送HTTP请求详解整合网站的支持！

来源：https://blog.csdn.net/weixin_38003389/article/details/88661280