Http协议笔记

/**
* Servlet implementation class HelloServlet
*/
@WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public HelloServlet() {
super();
// TODO Auto-generated constructor stub
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//this.execute(request, response);

//this.test1(response);
//this.test2(response);
//this.test3(response);
test5(response);
}

private void test5(HttpServletResponse response) throws IOException {
response.setHeader("content-disposition", "attachment;filename=apple.png");
InputStream in = this.getServletContext().getResourceAsStream("/apple.png");
int len = 0;
byte[] buffer = new byte[1024];
OutputStream out = response.getOutputStream();
while(  (len=in.read(buffer)) >0 )
{
out.write(buffer, 0, len);
}
}

public void test4( HttpServletResponse response) throws IOException
{
response.setHeader("refresh", "3;url='http://www.baidu.com'"); // will goto baidu after 3s
String data = "refresh";
response.getOutputStream().write(data.getBytes());
}

public void test3( HttpServletResponse response) throws IOException
{
response.setHeader("content-type", "image/png");
InputStream in = this.getServletContext().getResourceAsStream("/apple.png");
int len = 0;
byte[] buffer = new byte[1024];
OutputStream out = response.getOutputStream();
while(  (len=in.read(buffer)) >0 )
{
out.write(buffer, 0, len);
}
}

public void test2( HttpServletResponse response) throws IOException
{
String data = "jskdljasldjasldjsdlkasjdlkasjdlskdjd";
System.out.println("before size is: " + data.getBytes().length);
ByteArrayOutputStream bout = new ByteArrayOutputStream();
GZIPOutputStream gout = new GZIPOutputStream(bout);
gout.write(data.getBytes());
gout.close();
byte[] gzip = bout.toByteArray();
System.out.println("after size is: " + gzip.length);

response.setHeader("Content-Encoding", "gzip");
response.setHeader("Content-Length", gzip.length+"");
response.getOutputStream().write(gzip);
}

public void test1( HttpServletResponse response)
{
response.setStatus(302);
response.setHeader("location", "/WebTest/1.html");
}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//this.execute(request, response);
}

}