servlet path coding problems

A path coding problems

com.itstaredu.servlet Package; 

Import javax.servlet.ServletException; 
Import the javax.servlet.http.HttpServlet; 
Import the javax.servlet.http.HttpServletRequest; 
Import javax.servlet.http.HttpServletResponse; 
Import java.io.IOException; 

/ * * 
 * use an absolute path 
 * / project name / ...... 
 * absolute path begins with / 
 * when the dispatcher does not need to forward the project under the same name as a project 
 * with the project name server will resolve not to add 
 * browser parses do not add our own project name 
 * base tag <base href = "http: // localhost: 8080 / javaweb07 /" /> behind the increase in the relative path 
 * absolute path begins with / 
 * relative path does not start with / 
 * encoding issues ISO-8859- 1 
 * server re-re-encoding the decoded 
 * request Add URIEncoding = "UTF-8" or not in line connector tab server.xml 65 
 * <p>
 * request.setCharacterEncoding("UTF-8");
 * response.setContentType("text/html;charset=UTF-8");
 * response.setHeader("content-Type","text/html;charset=UTF-8");
 */
public class PathServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");

        . response.getWriter () write ( "Three Kingdoms");
        String name = request.getParameter("username0");
        System.out.println(name);
    }
}