Response的用法
阿新 • • 發佈：2019-01-06
1. 設定響應行的狀態碼
setStatus(int value)
response.setStatus(302);
2.設定響應頭
addHeader(String name,String value)
addIntHeader(String name,int value)
addDateHeader(String name,long value)
public class HeaderServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Date date = new Date(); response.addHeader("name", "xiaodingdang"); response.addHeader("name", "daxiong"); response.addIntHeader("age", 15); response.addDateHeader("birthday", date.getTime()); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
setHeader(String name,String value)
setIntHeader(String name ,int value)
setDateHeader(String name, long value)
public class HeaderServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Date date = new Date(); response.setHeader("name", "xiaodingdang"); response.setHeader("name", "daxiong"); response.setIntHeader("age", 15); response.setDateHeader("birthday", date.getTime()); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
注意了 要注意setHeader和addHeader的不同 一個是設定 一個是新增 設定只能是設定最後一個 但是新增可以新增很多個
3.response實現重定向
方法一：
response.setStatus(302); //設定響應行的狀態碼為302 重定向
response.setHeader("Location", "/Servlet/servlet2"); //設定響應頭的屬性 跳轉到Servlet2
方法二：
response.sendRedirect("/Servlet/servlet2"); //利用response中的sendRedirect屬性完成重定向
4.response實現自動重新整理跳轉
public class RefreshServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setHeader("refresh", "5;url=http://www.baidu.com"); //設定頭 引數 數值5為
//秒 中間用分號間隔 url為要跳轉的網址
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
使用JS來完成自動跳轉
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
window.onload= function(){
var time = 3;
var second = document.getElementById("second");
timer = setInterval(function(){
second.innerHTML = time;
time--;
if(time==0){
location.href = "http://www.baidu.com";
clearInterval(timer);
}
},1000);
}
</script>
</head>
<body>
恭喜你,登入成功，<span id="second" style="color: red">3</span>秒後將跳轉,若不跳轉 請點選<a href="http://www.baidu.com">這裡</a>
</body>
</html>
5.解決response中文亂碼問題
//方法一：
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setHeader("content-Type", "text/html;charset=utf-8");
response.getWriter().write("小叮噹");
}
//方法二：
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// response.setCharacterEncoding("UTF-8");
// response.setHeader("content-Type", "text/html;charset=utf-8");
response.setContentType("text/html;charset=utf-8");
response.getWriter().write("中國");
}
//通常使用第二種方法解決亂碼問題
6.上傳圖片資源
public class TestServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ServletOutputStream outputStream = response.getOutputStream(); //獲得位元組輸出流
String realPath = this.getServletContext().getRealPath("1.jpg"); //獲得圖片的真實路徑
InputStream in = new FileInputStream(realPath); //獲得伺服器上的圖片
//使用高效的方法寫入客戶端圖片
int len = 0;
byte[] buffer = new byte[1024];
while((len=in.read(buffer))>0) {
outputStream.write(buffer, 0, len);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
Response中應注意的細節
1.response獲得的流OutputStream不需要手動關閉,Tomcat容器會幫助我們關閉
但是InputStream需要手動關閉
2.getWriter和getOutputStream不能同時呼叫