java判断http地址是否连通(示例代码)

private boolean isOk(String url) {
        if(StrUtil.isEmpty(url)) return false;
        try {
            URL netUrl = new URL(url);
            HttpURLConnection connection = (HttpURLConnection) netUrl.openConnection();
            connection.setConnectTimeout(3000); //连接主机超时时间ms
            connection.setReadTimeout(3000); //从主机读取数据超时时间ms
            if (HttpURLConnection.HTTP_OK == connection.getResponseCode()) {
                System.out.println("网络联通！");
                return true;
            }
        } catch (IOException e) {
            log.error("连接不通", e.getMessage());
            return false;
        }
        return false;
    }

System.setProperty("sun.net.client.defaultConnectTimeout", "30000");  

System.setProperty("sun.net.client.defaultReadTimeout", "30000");  

HttpURLConnection urlCon = (HttpURLConnection)url.openConnection();  

urlCon.setConnectTimeout(30000);  

urlCon.setReadTimeout(30000);