一、向客户端写入数据
1、写入文字
protected voiddoGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");//设置服务器的编码，默认是ISO-8859-1
response.setContentType("text/html; charset = utf-8");//告诉浏览器服务器的编码格式
response.getWriter().write("你好，JAVA");
}
2、图片
protected voiddoGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ServletOutputStreamout=response.getOutputStream();
File file=new File("图片路径");
FileInputStream fi= newFileInputStream(file);byte[] buf = new byte[1024];int len = 0;while ((len = fi.read(buf)) != -1) {out.write(buf, 0, len); //将数组中的指定长度的数据写入到输出流中。
}
fi.close();out.close();
}
采用了缓冲数组读入图片数据，减少了时间的消耗。创建ServletOutputStream对象，将数据输出到了客户端。
二、response对响应的设置
1、response对象设置响应行状态码：
protected voiddoGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setStatus(404);
}
2、response对象添加响应头：
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Date date=new Date(121344444);
response.addHeader("zzz","I love JAVA.");
response.addIntHeader("myself",22);
response.addDateHeader("Time:",date.getTime());
}
3、response对象设置响应头：
protected void doGet(HttpServletRequest request, HttpServletResponse response) throwsServletException, IOException {
Date date=new Date(121344444);
response.addHeader("zzz","I love JAVA.");
response.addIntHeader("myself",22);
response.addDateHeader("Time:",date.getTime());
response.setIntHeader("myself",23);
}
