Android入门：封装一个HTTP请求的辅助类

前面的文章中，我们曾经实现了一个HTTP的GET 和 POST 请求；

此处我封装了一个HTTP的get和post的辅助类，能够更好的使用；

类名：HttpRequestUtil

提供的方法：
(1) public static URLConnection sendGetRequest(String url,Map<String, String> params, Map<String, String> headers)

参数：

(1)url：单纯的URL，不带任何参数；

(2)params：参数；

(3)headers：需要设置的HTTP请求头；

返回：

HttpURLConnection

(2)public static URLConnection sendPostRequest(String url,Map<String, String> params, Map<String, String> headers)

参数：

(1)url：单纯的URL，不带任何参数；

(2)params：参数；

(3)headers：需要设置的HTTP请求头；

返回：

HttpURLConnection

package com.xiazdong.network.http.util;

import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public class HttpRequestUtil {

	public static URLConnection sendGetRequest(String url,
			Map<String, String> params, Map<String, String> headers)
			throws Exception {
		StringBuilder buf = new StringBuilder(url);
		buf.append("?");
		Set<Entry<String, String>> entrys = params.entrySet();
		for (Map.Entry<String, String> entry : entrys) {
			buf.append(entry.getKey()).append("=")
					.append(URLEncoder.encode(entry.getValue(), "UTF-8"))
					.append("&");
		}
		buf.deleteCharAt(buf.length() - 1);
		URL url1 = new URL(buf.toString());
		HttpURLConnection conn = (HttpURLConnection) url1.openConnection();
		conn.setRequestMethod("GET");
		if (headers != null) {
			entrys = headers.entrySet();
			for (Map.Entry<String, String> entry : entrys) {
				conn.setRequestProperty(entry.getKey(), entry.getValue());
			}
		}
		conn.getResponseCode();
		return conn;
	}

	public static URLConnection sendPostRequest(String url,
			Map<String, String> params, Map<String, String> headers)
			throws Exception {
		StringBuilder buf = new StringBuilder();
		Set<Entry<String, String>> entrys = params.entrySet();
		for (Map.Entry<String, String> entry : entrys) {
			buf.append(entry.getKey()).append("=")
					.append(URLEncoder.encode(entry.getValue(), "UTF-8"))
					.append("&");
		}
		buf.deleteCharAt(buf.length() - 1);
		URL url1 = new URL(url);
		HttpURLConnection conn = (HttpURLConnection) url1.openConnection();
		conn.setRequestMethod("POST");
		conn.setDoOutput(true);
		OutputStream out = conn.getOutputStream();
		out.write(buf.toString().getBytes("UTF-8"));
		if (headers != null) {
			entrys = headers.entrySet();
			for (Map.Entry<String, String> entry : entrys) {
				conn.setRequestProperty(entry.getKey(), entry.getValue());
			}
		}
		
		conn.getResponseCode(); // 为了发送成功
		return conn;
	}
}

此后，像前面文章中的例子，我们可以很简单的通过如下方式实现：

Map<String,String> params = new HashMap<String,String>();
params.put("name", name.getText().toString());
params.put("age", age.getText().toString());
HttpURLConnection conn = (HttpURLConnection) HttpRequestUtil.sendGetRequest("http://192.168.0.103:8080/Server/PrintServlet", params, null);

简单了很多，对吧？