Java网络编程知识点（1）

怎样将一个String对象转换成InputStream对象？

ByteArrayInputStream inputStream = new ByteArrayInputStream(str.getBytes());

怎样替换掉网络URL里面的參数值？

String baseURL = "http://sixweather.3gpk.net/SixWeather.aspx?city=%s";
String cityName = "武汉";

String resultURL = String.format(baseURL, cityName);

怎样在Java中訪问网络地址，获取返回结果？

// **************訪问网络，获取天气预报数据，将结果数据存储到result中*******************
				//初始化httpGet，将參数url传给它
				HttpGet httpGet = new HttpGet(url);

				String result = "";

				//初始化httpClient
				HttpClient httpClient = new DefaultHttpClient();

				//调用httpClient的execute方法，返回一个HttpResponse的实例
				HttpResponse httpResponse = httpClient.execute(httpGet);

				if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
					//将httpResponse中的天气数据转换成字符串形式
					result = EntityUtils.toString(httpResponse.getEntity());
				}

// ****************************************************************************************

怎样在Java中对字符串String进行编码、解码操作？

		String cityName = "武汉";

		try {
			//对cityName进行utf-8编码操作
			cityName = URLEncoder.encode(cityName, "utf-8");

			//对cityName进行utf-8解码操作
			cityName = URLDecoder.decode(cityName, "utf-8");

		} catch (Exception e) {
			e.printStackTrace();
		}