$api="http://api.veapi.cn/douke/materials_ProductCategory?vekey=xxx&parent_id=0";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $api);
//curl_setopt($ch, CURLOPT_POST, true);  //POST方式时启用
//curl_setopt($ch, CURLOPT_POSTFIELDS, $postData );  //POST方式时传参

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);  //如果使用https请启用
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);  //如果使用https请启用
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true );   //返回数据流，不直接输出
curl_setopt($ch, CURLOPT_ENCODING, 'gzip'); //使用gzip压缩传输让访问更快
curl_setopt($ch, CURLOPT_TIMEOUT, 6);  //允许执行的最长秒数。这里设定6S
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);

$result = curl_exec($ch);
$info = curl_getinfo($ch);
curl_close($ch);

echo $result; //返回值

import cn.hutool.http.HttpResponse;
import cn.hutool.http.HttpRequest;

public class testGetParam {

    public static void main(String[] args) {
        // API网址
        String url = "http://api.veapi.cn/douke/materials_ProductCategory?vekey=xxx&parent_id=0";
        // JDK 8u111版本后，若目标页面为HTTPS协议，请启用proxy用户密码鉴权
        //System.setProperty("jdk.http.auth.tunneling.disabledSchemes", "");

        // 发送请求
        String result = HttpRequest.get(url)
                .timeout(10000)//设置超时，毫秒
                .execute().body();
        System.out.println(result);
    }
}

import requests
		
# 要访问的API网页
target_url = "http://api.veapi.cn/douke/materials_ProductCategory?vekey=xxx&parent_id=0"

# 发送请求
response = requests.get(target_url)

# 获取页面内容
if response.status_code == 200:
	print response.text