java使用httpcomponents发送get请求

一、适用场景

　　在ESTful webservice中，get方法一般都是用来获取数据。我们可以使用httpcomponents组件来完成调用。

　　如我们需要发起get请求，携带的参数都是附加到请求的url后面。

　　url："http://www.xxxxx.com/message?id=000010"

二、代码示例

package com.demo.test;

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class Test2 {

    public static String sendInfo(String url, String param) {
        String geturl = String.format("%s?id=%s", url, param);
        CloseableHttpClient client = HttpClients.createDefault();
        HttpGet get = new HttpGet(geturl);
        String responseContent = null; // 响应内容
        CloseableHttpResponse response = null;
        try {
            response = client.execute(get);
            HttpEntity entity = response.getEntity();// 响应体
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {// 正确返回
                responseContent = EntityUtils.toString(entity, "UTF-8");
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (response != null)
                    response.close();
                if (client != null)
                    client.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return responseContent;
    }

    public static void main(String[] args) {
        String param = "000010";
        String result = sendInfo("http://www.xxxxx.com/message", param);
        System.out.println(result);
    }
}

　　请求成功后，后天会打印返回的信息。