HttpClient--使用HttpClient进行Get Post请求访问

在java后台开发中，我们有时候需要调用其他网站的接口进行数据的获取操作，我们一般会采用

　　1.java net 包中的URL 类，进行网络的数据获取

　　2.使用apache提供的HttpClient进行网络中数据的获取;

这里我们使用第二种方式，使用apache 提供的HttpClient进行数据的获取，接口的对接，下面附上HttpClientUtil 工具类，实现了POST与GET方法

1.引入pom依赖

<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.3.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.3.1</version>
</dependency>

package com.project.utils;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
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.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;

public class HttpClientUtils {

    //使用HttpClient 进行doGET请求
    public static String doGet(String url) throws Exception {

        CloseableHttpClient httpclient =HttpClients.createDefault();
        HttpGet httpget =new HttpGet(url);
        try {
            HttpResponse response=httpclient.execute(httpget);
            //创建响应处理器处理服务器响应内容
            String content =  Utf8ResponseHandler.INSTANCE.handleResponse(response);

            return content;

            }

        finally {
            httpget.releaseConnection();
          }

    }

    public static void main(String[] args) throws Exception {

        String str=doPOST("https://api.weixin.qq.com/cgi-bin/menu/create?access_token=ACCESS_TOKEN","nm");
        System.out.println(str);

    }

    //使用HttpClient 进行dopOSTT请求,适合发送的数据为json数据格式
        public static String doPOST(String url,String outstr) throws Exception {

            //DefaultHttpClient httpclient =new DefaultHttpClient();//老版本的方法
            CloseableHttpClient httpclient =HttpClients.createDefault();
            HttpPost httppost =new HttpPost(url);
            String result =null;
            try {
                httppost.setEntity(new StringEntity(outstr, "UTF-8"));
                HttpResponse response=httpclient.execute(httppost);
                //创建响应处理器处理服务器响应内容
                String content =  Utf8ResponseHandler.INSTANCE.handleResponse(response);

                return content;

            }
            finally {

                httppost.releaseConnection();
            }

        }

　　　　
//传递form 表单
public static String NameValue(String URL,Map<String,String> formArgs) throws Exception {

HttpClient httpclient = HttpClients.createDefault();

HttpPost post =new HttpPost(URL);

List<BasicNameValuePair> data =new ArrayList<BasicNameValuePair>();

for(Map.Entry<String, String> entry :formArgs.entrySet()) {

data.add(new BasicNameValuePair(entry.getKey(), entry.getValue()) );
}
try {
post.setEntity(new UrlEncodedFormEntity(data));

HttpResponse response=httpclient.execute(post);

String content = Utf8ResponseHandler.INSTANCE.handleResponse(response);

return content;
}
finally {

post.releaseConnection();
}

}

}　　

创建响应处理器--utf-8编码（需要继承ResponseHandler 实现自己的方法，官方也有自己默认的一套实现方法BasicResponseHandler，但不能设置编码）

package com.project.utils;

import java.io.IOException;

import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpResponseException;
import org.apache.http.client.ResponseHandler;
import org.apache.http.util.EntityUtils;

public class Utf8ResponseHandler implements ResponseHandler<String> {

    /*
     *实现utf-8编码的返回数据类型，实现ttpclient ResponseHandler接口方法
     *
     *copy from {@link org.apache.http.impl.client.BasicResponseHandler}官方默认提供
     */
    public static final ResponseHandler<String> INSTANCE = new Utf8ResponseHandler();

    @Override
    public String handleResponse(HttpResponse response) throws ClientProtocolException, IOException {
         final StatusLine statusLine = response.getStatusLine();
            final HttpEntity entity = response.getEntity();
            if (statusLine.getStatusCode() >= 300) {
              EntityUtils.consume(entity);
              throw new HttpResponseException(statusLine.getStatusCode(), statusLine.getReasonPhrase());
            }
            return entity == null ? null : EntityUtils.toString(entity, Consts.UTF_8);
          }

    }