Get,Post请求

本文代码来自传智播客PPT
GET方法：
利用HttpURLConnection对象,我们可以从网络中获取网页数据.
 

/**
	 * Get 请求
	 * 
	 * @param reqUrl
	 * @return String
	 */
	public static String get(String reqUrl) {
		logger.info("GET Request,Url:" + reqUrl);
		InputStream is = null;
		HttpURLConnection conn = null;
		String result = "";
		try {
			URL url = new URL(reqUrl);
			conn = (HttpURLConnection) url.openConnection();
			conn.setConnectTimeout(5 * 1000);// 设置连接超时
			conn.setRequestMethod(WXConstants.METHOD_GET);// 以get方式发起请求
			if (conn.getResponseCode() != 200)
				throw new RuntimeException("请求url失败");
			is = conn.getInputStream();// 得到网络返回的输入流
			result = readData(is, "UTF-8");
			conn.disconnect();
		} catch (Exception e) {
			e.printStackTrace();
		} finally{
			if(null != is){
				try {
					is.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			
			if(null != conn){
				conn.disconnect();
			}
		}
		return result;
	}

POST方法：
利用HttpURLConnection对象,我们可以向网络发送请求参数.
 

/**
	 * POST 请求
	 * 
	 * @param reqUrl
	 * @param reqParams
	 * @return String
	 */
	public static String post(String reqUrl, String params) {
		logger.info("POST Request,Url:" + reqUrl);
		DataOutputStream outStream = null;
		HttpURLConnection conn = null;
		String result = "";
		try {
			byte[] data = params.toString().getBytes();
			URL realUrl = new URL(reqUrl);
			conn = (HttpURLConnection) realUrl
					.openConnection();
			conn.setDoOutput(true);// 发送POST请求必须设置允许输出
			conn.setUseCaches(false);// 不使用Cache
			conn.setRequestMethod(WXConstants.METHOD_POST);
			conn.setRequestProperty("Connection", "Keep-Alive");// 维持长连接
			conn.setRequestProperty("Charset", "UTF-8");
			conn.setRequestProperty("Content-Length",
					String.valueOf(data.length));
			conn.setRequestProperty("Content-Type",
					"application/x-www-form-urlencoded");
			outStream = new DataOutputStream(
					conn.getOutputStream());
			outStream.write(data);
			outStream.flush();
			if (conn.getResponseCode() == 200) {
				result = readData(conn.getInputStream(), "UTF-8");
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally{
			if(null != outStream){
				try {
					outStream.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			
			if(null != conn){
				conn.disconnect();
			}
		}
		return result;
	}

/**
	 * 第一个参数为输入流,第二个参数为字符集编码
	 * 
	 * @param inSream
	 * @param charsetName
	 * @return String
	 * @throws Exception
	 */
	private static String readData(InputStream inSream, String charsetName)
			throws Exception {
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] buffer = new byte[1024];
		int len = -1;
		while ((len = inSream.read(buffer)) != -1) {
			outStream.write(buffer, 0, len);
		}
		byte[] data = outStream.toByteArray();
		outStream.close();
		inSream.close();
		return new String(data, charsetName);
	}

问题：ajax get编码
1、get方法传文字字符串就会有乱码，因为是通过url传参的。
所以你要在js客户端经过2次转码，同样服务器端也要转码。

$.get("AjaxService?userName=" + encodeURI(encodeURI(userName)), null, function (data) {
$("#result").html(data);
});

这2个效果是一样的：

encodeURIComponent(userName) 、 encodeURI(encodeURI(userName))

服务器端转码：

String userName = URLDecoder.decode(request.getParameter("userName"), "UTF-8");

2、将tomcat服务端server.xml中<Connector ... URIEncoding="UTF-8"/>设置成这样，但tomcat布署在windows上还是有问题，在linux布署tomcat没有问题。可能是因为windows是gb2312的编码，而linux本身就是utf-8编码