第一种：

    public static String getURLContent(String urlStr) {
        /** 网络的url地址 */
        URL url = null;
        /** http连接 */
        HttpURLConnection httpConn = null;
        /**//** 输入流 */
        BufferedReader in = null;
        StringBuffer sb = new StringBuffer();
        try {
            url = new URL(urlStr);
            in = new BufferedReader(new InputStreamReader(url.openStream(), "GBK"));
            String str = null;
            while ((str = in.readLine()) != null) {
                sb.append(str);
            }
        } catch (Exception ex) {
 
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
            }
        }
        String result = sb.toString();
        System.out.println(result);
        return result;
    }

第二种：

//http请求返回json
            public static String httpGetJson(String url){
                    String result = "";
                    BufferedReader in = null;
                    try {
                        String urlNameString = url;
                        URL realUrl = new URL(urlNameString);
                        // 打开和URL之间的连接
                        URLConnection connection = realUrl.openConnection();
                        // 设置通用的请求属性
                        //connection.setRequestProperty("contentType", "utf8");  
                        connection.setReadTimeout(5000);
                        connection.setRequestProperty("accept", "*/*");
                        connection.setRequestProperty("connection", "Keep-Alive");
                        connection.setRequestProperty("user-agent",
                                "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
                        // 建立实际的连接
                        connection.connect();
                        // 获取所有响应头字段
                       // Map<String, List<String>> map = connection.getHeaderFields();
            
                  
                        // 定义 BufferedReader输入流来读取URL的响应
                        in = new BufferedReader(new InputStreamReader(
                                connection.getInputStream(),"UTF-8"));//防止乱码
                        String line;
                        while ((line = in.readLine()) != null) {
                            result += line;
                        }
                    } catch (Exception e) {
                        //System.out.println("发送GET请求出现异常！" + e);
                        e.printStackTrace();
                        result="";
                    }
                    // 使用finally块来关闭输入流
                    finally {
                        try {
                            if (in != null) {
                                in.close();
                            }
                        } catch (Exception e2) {
                            e2.printStackTrace();
                        }
                    }
                   // System.out.println("123");
                    
                    return result;
            }