http

在pom.xml增加httpclient

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.example</groupId>
  <artifactId>json</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>json</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
    <dependency>
      <groupId>org.apache.httpcomponents</groupId>
      <artifactId>httpclient</artifactId>
      <version>4.5.6</version>
    </dependency>
  </dependencies>
</project>

封装操作类

package com.example;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
 * HttpClient工具类
 */
public class HttpUtil {
    //private static Logger logger = Logger.getLogger(HttpUtil.class);
    /**
     * get请求
     * @return
     */
    public static String get(String url,Map<String,String>headers){
        String result = "";
        try {
            // 构造httprequest设置
            RequestConfig config = RequestConfig.custom().setConnectTimeout(5)
                    .setConnectionRequestTimeout(10).build();
            HttpClient client = HttpClientBuilder.create().setDefaultRequestConfig(config).build();
            HttpGet htGet = new HttpGet(url);
            // 添加http headers
            if (headers != null && headers.size() > 0) {
                for (String key : headers.keySet()) {
                    htGet.addHeader(key, headers.get(key));
                }
            }
            // 读取数据
            HttpResponse response = client.execute(htGet);
            result = EntityUtils.toString(response.getEntity(), "utf-8");
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        return result;
    }
    /*
     不带参数请求
     */
    public static String get(String url) {
          return  get(url,null);
    }
    /**
     * post请求(用于key-value格式的参数)
     * @param url
     * @param param
     * @return
     */
    public static String post(String url, Map<String, String> param) {
        return post(url,param,null);
    }
    public  static  String post(String url,Map<String,String> param,Map<String,String> headers){
        String result="";
        try {
            // 构造httprequest设置
            RequestConfig config = RequestConfig.custom().setConnectTimeout(5)
                    .setConnectionRequestTimeout(10).build();
            HttpClient client = HttpClientBuilder.create().setDefaultRequestConfig(config).build();
            HttpPost httpPost = new HttpPost(url);
            if (param != null) {
                List<NameValuePair> paramList = new ArrayList<NameValuePair>();
                for (String key : param.keySet()) {
                    paramList.add(new BasicNameValuePair(key, param.get(key)));
                }
                // 模拟表单
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList, "utf-8");
                httpPost.setEntity(entity);
            }
            // 添加http headers
            if (headers != null && headers.size() > 0) {
                for (String key : headers.keySet()) {
                    httpPost.addHeader(key, headers.get(key));
                }
            }
            // 读取数据
            HttpResponse response = client.execute(httpPost);
            result = EntityUtils.toString(response.getEntity(), "utf-8");
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        return result;
    }
}