java网络请求工具类（java.net API）

代码如下：

public static String httpGet(String url) {//参数拼接在地址上了
		StringBuilder inputLine = new StringBuilder();
		try {
			URL fixposition = new URL(url);
			HttpURLConnection connection = (HttpURLConnection) fixposition.openConnection();// 打开连接

			connection.setConnectTimeout(1000);
			connection.setReadTimeout(1000);
			
			connection.connect();// 连接会话
			BufferedReader in = new BufferedReader(new InputStreamReader(fixposition.openStream(), "UTF-8"));
			try {
				String readLine;
				while ((readLine = in.readLine()) != null) {
					inputLine.append(readLine);
				}
			} finally {
				in.close();
			}
			return inputLine.toString();
		} catch (Exception e) {
			//自行处理异常
		}
		return null;
	}

public static String httpPost(String url, String param) {
		PrintWriter out = null;
		BufferedReader in = null;
		StringBuilder result = new StringBuilder();
		try {
			URL realUrl = new URL(url);
			// 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.append(line);
			}
		} catch (Exception e) {
			//自行处理异常
		}
		
		//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) {
				//自行处理异常
			}
		}
		return result.toString();
	}

// 获取大文件
public static byte[] httpGetBin(String urlStr) throws Exception {

		int bytesum = 0;
		int byteread = 0;
		int byteLen = 1024;
		byte[] allBuffer = new byte[byteLen];
		URL url = null;
		url = new URL(urlStr);
		URLConnection conn = url.openConnection();

		conn.setConnectTimeout(1000);
		conn.setReadTimeout(1000);
		InputStream inStream = conn.getInputStream();
		byte[] buffer = new byte[1204];
		while ((byteread = inStream.read(buffer)) != -1) {
			//内容太大，扩大内存
			if (bytesum + byteread > byteLen) {
				byteLen = (bytesum + byteread) * 2;
				byte[] tmp = new byte[byteLen];
				System.arraycopy(allBuffer, 0, tmp, 0, bytesum);
				allBuffer = tmp;
			}
			System.arraycopy(buffer, 0, allBuffer, bytesum, byteread);
			bytesum += byteread;

		}
		byte[] ret = new byte[bytesum];
		System.arraycopy(allBuffer, 0, ret, 0, bytesum);
		return ret;

	}