/**
 * Copyright (c) 2015-2016, Chill Zhuang 庄骞 (smallchill@163.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.stylefeng.guns.core.support;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

public class HttpKit {
	
	/**   
	 * 获取 HttpServletRequest
	*/
	public static HttpServletResponse getResponse() {
		HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();
		return response;
	}

	/**   
	 * 获取 包装防Xss Sql注入的 HttpServletRequest
	 * @return request
	*/
	public static HttpServletRequest getRequest() {
		HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
		return new WafRequestWrapper(request);
	}

	/**
	 * 向指定URL发送GET方法的请求
	 * 
	 * @param url 发送请求的URL
	 * @param param 请求参数
	 * @return URL 所代表远程资源的响应结果
	 */
	public static String sendGet(String url, Map<String, String> param) {
		String result = "";
		BufferedReader in = null;
		try {
			String para = "";
			for (String key : param.keySet()) {
				para += (key + "=" + param.get(key) + "&");
			}
			if (para.lastIndexOf("&") > 0) {
				para = para.substring(0, para.length() - 1);
			}
			String urlNameString = url + "?" + para;
			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("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();
			// 遍历所有的响应头字段
			for (String key : map.keySet()) {
				System.out.println(key + "--->" + map.get(key));
			}
			// 定义 BufferedReader输入流来读取URL的响应
			in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
			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();
		}
		// 使用finally块来关闭输入流
		finally {
			try {
				if (in != null) {
					in.close();
				}
			} catch (Exception e2) {
				e2.printStackTrace();
			}
		}
		return result;
	}

	/**
	 * 向指定 URL 发送POST方法的请求
	 * 
	 * @param url 发送请求的 URL
	 * @param param  请求参数
	 * @return 所代表远程资源的响应结果
	 */
	public static String sendPost(String url, Map<String, String> param) {
		PrintWriter out = null;
		BufferedReader in = null;
		String result = "";
		try {
			String para = "";
			for (String key : param.keySet()) {
				para += (key + "=" + param.get(key) + "&");
			}
			if (para.lastIndexOf("&") > 0) {
				para = para.substring(0, para.length() - 1);
			}
			String urlNameString = url + "?" + para;
			URL realUrl = new URL(urlNameString);
			// 打开和URL之间的连接
			URLConnection conn = realUrl.openConnection();
			// 设置通用的请求属性
			conn.setRequestProperty("accept", "*/*");
			conn.setRequestProperty("connection", "Keep-Alive");
			conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
			// 发送POST请求必须设置如下两行
			conn.setDoOutput(true);
			conn.setDoInput(true);
			// 获取URLConnection对象对应的输出流
			out = new PrintWriter(conn.getOutputStream());
			// 发送请求参数
			out.print(param);
			// flush输出流的缓冲
			out.flush();
			// 定义BufferedReader输入流来读取URL的响应
			in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
			String line;
			while ((line = in.readLine()) != null) {
				result += line;
			}
		} catch (Exception e) {
			System.out.println("发送 POST 请求出现异常！" + e);
			e.printStackTrace();
		}
		// 使用finally块来关闭输出流、输入流
		finally {
			try {
				if (out != null) {
					out.close();
				}
				if (in != null) {
					in.close();
				}
			} catch (IOException ex) {
				ex.printStackTrace();
			}
		}
		return result;
	}
	
}
