HttpClient4.X发送Get请求的url参数拼接

HttpClient4.X发送Get请求的参数拼接

使用httpClient发送get请求时，请求参数可以以？key=val&key1=val1的拼接到url后面。
但是请求参数较多时，这种方法比较麻烦，也不太优雅；研究了一下发现HttpClient4.X本身
是支持处理参数的。

1. 使用 URIBuilder来构建请求URI

httpclient相关的jar包mvn依赖：

<dependency> ???<groupId>org.apache.httpcomponents</groupId> ???<artifactId>httpcore</artifactId> ???<version>4.4.3</version></dependency><dependency> ???<groupId>org.apache.httpcomponents</groupId> ???<artifactId>httpclient</artifactId> ???<version>4.5.1</version></dependency>

import com.google.common.collect.Lists;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.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.utils.URIBuilder;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; ???private HttpGet buildHttpGet(String url, Map<String, String> para) ???????????throws URISyntaxException { ???????URIBuilder builder = new URIBuilder(url); ???????Set<String> set = para.keySet(); ???????for(String key: set){ ???????????builder.setParameter(key, para.get(key)); ???????} ???????HttpGet request = new HttpGet(builder.build()); ???????RequestConfig requestConfig = RequestConfig.custom() ???????????????.setSocketTimeout(6000) ???????????????.setConnectTimeout(6000) ???????????????.setConnectionRequestTimeout(6000).build(); ???????request.setConfig(requestConfig); ???????System.out.println(request.getURI().toString()); ???????return request; ???}

2. 使用 NameValuePair 来拼接URI

List<NameValuePair> params = Lists.newArrayList();params.add(new BasicNameValuePair("cityEname", "henan"));String str = "";//转换为键值对str = EntityUtils.toString(new UrlEncodedFormEntity(params, Consts.UTF_8));System.out.println(str);HttpGet httpGet = new HttpGet(url + "?" + str);

3. 根据 HttpGet反向获取键值对列表

HttpGet request = new HttpGet("http://example.com/?var=1&var=2");URIBuilder newBuilder = new URIBuilder(request.getURI());//获取键值对列表List<NameValuePair> params = newBuilder.getQueryParams();//转换为键值对字符串String str = EntityUtils.toString(new UrlEncodedFormEntity(params, Consts.UTF_8));