Android学习（47） -- Html源文件查看器

发送GET请求

URL url = new URL(path);
//获取连接对象
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//设置连接属性
conn.setRequestMethod("GET");
conn.setConnectTimeout(5000);
conn.setReadTimeout(5000);
//建立连接，获取响应吗
if(conn.getResponseCode() == 200){

}

获取服务器返回的流，从流中把html源码读取出来

由于构建字符串String，可以通过new String(byte[] )来构建，而ByteArrayOutputStream 可以调用.toByteArray()，能够将流直接转换为字节数组

byte[] b = new byte[1024];
int len = 0;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
while((len = is.read(b)) != -1){
    //把读到的字节先写入字节数组输出流中存起来
    bos.write(b, 0, len);
}
//把字节数组输出流中的内容转换成字符串
//默认使用utf-8
text = new String(bos.toByteArray());

乱码的处理

乱码的出现是因为服务器和客户端码表不一致导致

//手动指定码表
text = new String(bos.toByteArray(), "utf-8");

核心代码

public class MainActivity extends Activity {

	Handler handler = new Handler(){
		public void handleMessage(android.os.Message msg) {
			TextView tv = (TextView) findViewById(R.id.tv);
			tv.setText((String)msg.obj);
		}
	};
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}

	public void click(View v){
		Thread t = new Thread(){
			@Override
			public void run() {
				String path = "http://192.168.1.103:8080/baidu.html";
				try {
					URL url = new URL(path);
					//获取连接对象，此时还未建立连接
					HttpURLConnection conn = (HttpURLConnection) url.openConnection();
					conn.setRequestMethod("GET");
					conn.setConnectTimeout(5000);
					conn.setReadTimeout(5000);
					//先建立连接，然后获取响应码
					if(conn.getResponseCode() == 200){
						//拿到服务器返回的输入流，流里的数据就是html的源文件
						InputStream is = conn.getInputStream();
						//从流里把文本数据取出来
						String text = Utils.getTextFromStream(is);
						
						//发送消息，让主线程刷新ui，显示源文件
						Message msg = handler.obtainMessage();
						msg.obj = text;
						handler.sendMessage(msg);
					}
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		};
		t.start();
		
	}

}

从流中获取到字符串

public class Utils {

	public static String getTextFromStream(InputStream is){
		
		byte[] b = new byte[1024];
		int len = 0;
		//创建字节数组输出流，读取输入流的文本数据时，同步把数据写入数组输出流
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		try {
			while((len = is.read(b)) != -1){
				bos.write(b, 0, len);
			}
			//把字节数组输出流里的数据转换成字节数组
			String text = new String(bos.toByteArray());
			return text;
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}
}