HttpServletResponse类、重定向

Tomcat服务器每次接收到一个请求都会和HttpServletRequest类一样创建一个HttpServletResponse对象，用来设置给客户端回传的响应信息

1.以流的形式向客户端传输数据

public class Web06 extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//解决响应中文乱码问题

resp.setContentType("text/html;charset=utf-8");

//获取字节流

//ServletOutputStream outputStream = resp.getOutputStream();

//获取字符流

PrintWriter writer = resp.getWriter();

writer.write("哈哈哈哈");

}

}

2.重定向

客户端向服务端发送Servlet1程序的请求，Servlet1程序将Servlet2程序的请求地址回传给客户端，让客户端发送Servlet2的请求

public class Response1 extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

String username = req.getParameter("username");

req.setAttribute("key", username);

resp.sendRedirect("http://localhost:8090/myWebApp/res2");

}

}

public class Response2 extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//设置客户端与服务器的编码都为utf-8

resp.setContentType("text/html;charset=utf-8");

PrintWriter writer = resp.getWriter();

writer.write("重定向成功");

}

}

1)重定向相当于客户端发送两次请求

2)地址栏会发生改变

3)不会共享request对象

4)重定向的请求需要填写绝对路径