我是 servlet 开发的新手，我正在阅读一本电子书，发现我可以使用
重定向到不同的网页setHeader("Location", "http://www.google.com")
但这不起作用，因为我将这段代码编写为:
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class ModHelloWorld extends HttpServlet{
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException{
// response.addHeader("Location", "http://www.google.com");
response.setHeader("Location", "http://www.google.com");
response.setContentType("text/html");
PrintWriter pw = response.getWriter();
pw.println("<html><head><title>Modified Hello World</title></head><body>");
pw.println("<h1>");
//getInitParameter function reads the contents ot init-param elements.
pw.println(getInitParameter("message"));
pw.println("</h1>");
pw.println("</body></html>");
pw.close();
}
}
我已经使用我的程序检查了标题以获取网页的标题，如下所示:
import java.net.*;
import java.io.*;
class getHeaders{
public static void main(String args[]){
URL url = null;
URLConnection urc = null;
try {
url = new URL(args[0]);
urc = url.openConnection();
for(int i=0 ; ; i++) {
String name = urc.getHeaderFieldKey(i);
String value = urc.getHeaderField(i);
if(name == null && value == null)//both null so end of header
break;
else if(name == null){//first line of header{
System.out.println("Server HTTP version, Response code: ");
System.out.println(value);
System.out.println("ENd of first header field");
} else {
System.out.println("name of header is: " + name + " and its value is : " + value);
}
}
} catch(MalformedURLException e){
System.out.println("Malformed URL " + e.getMessage());
} catch(IOException e){
e.printStackTrace();
}
}
}
我得到的输出是:
Server HTTP version, Response code:
HTTP/1.1 200 OK
ENd of first header field
name of header is: Server and its value is : Apache-Coyote/1.1
name of header is: Location and its value is : http://www.google.com
name of header is: Content-Type and its value is : text/html
name of header is: Content-Length and its value is : 101
name of header is: Date and its value is : Sat, 05 Mar 2011 15:27:29 GMT
但是我的浏览器没有重定向到谷歌的页面。
提前致谢:)
最佳答案
哦不不!这不是你重定向的方式。它更简单:
public class ModHelloWorld extends HttpServlet{
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException{
response.sendRedirect("http://www.google.com");
}
}
此外，在 servlet 中编写 HTML 代码也是一种不好的做法。您应该考虑将所有这些标记放入 JSP 并使用以下方法调用 JSP:
response.sendRedirect("/path/to/mynewpage.jsp");
关于java - 使用 servlet 重定向请求并且 "setHeader"方法不起作用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5204768/