- 关于servlet3.0 介绍不多说,直接进入开发主题
先写个登陆页面,代码如下
- index.jsp 页面
-
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% String msg = request.getParameter("msg"); %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" -
"http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>用户登陆</title> </head> <body> <form action="login" method="post" style="text-align: center;"> <h1>用户登陆</h1> 用户名:<input type="text" name="username"> <br/> 密 码：<input type="password" name="password"> <br/> <input type="submit" value="登陆"><br/> <span id="msg"><%=msg %></span> </form> <script type="text/javascript"> var msg = <%=msg%>; if(msg==null){ document.getElementById("msg").style.display = "none"; } </script> </body> </html>原来需要在web.xml中配置,如下，在servlet3.0中通过注解功能，不再需要web.xml配置
-
<servlet> <servlet-name>login</servlet-name> <servlet-class>com.action.Login</servlet-class> </servlet> <servlet-mapping> <servlet-name>login</servlet-name> <url-pattern>/login</url-pattern> </servlet-mapping>
servlet 代码如下
-
package com.action; import java.io.IOException; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.annotation.WebInitParam; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * @author zhuweishi * @version 1.1.0 */ /* * @SuppressWarnings 表示不提示警告信息 * @WebServlet * name 相当于web.xml中servlet的servlet-name * urlPatterns servlet-maring 中的url-pattern * loadOnStartup 加载顺序 * inintParams 初始值 */ @SuppressWarnings("serial") @WebServlet(name="Test",urlPatterns={"/login","/test/login"},loadOnStartup=1, -
initParams={@WebInitParam(name="usname",value="张三")}) public class Login extends HttpServlet{ @Override public void init(ServletConfig config) throws ServletException { //ServletConfig config = this.getServletConfig(); String usname = config.getInitParameter("usname"); System.out.println(usname+"-----"); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String username = req.getParameter("username"); String password = req.getParameter("password"); System.out.println(username+"==="+password); resp.setCharacterEncoding("UTF-8"); if("sysadmin".equals(username)){ if("000000".equals(password)){ // 设置作用域 req.setAttribute("username", username); //转发 req.getRequestDispatcher("/login.jsp").forward(req,resp); }else{ String msg = java.net.URLEncoder.encode("密码错误!", "utf-8"); resp.sendRedirect(req.getContextPath()+"/index.jsp?msg="+msg); } }else{ // 解决中文乱码 String msg = java.net.URLEncoder.encode("用户名错误!", "utf-8"); resp.sendRedirect(req.getContextPath()+"/index.jsp?msg="+msg); } } }
写一个 中文乱码的Filter
package com.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
/*
* 原来 web.xml 配置
* <filter>
* <filter-name>UTFFilter</filter-name>
* <filter-class>com.action.UTFFilter</filter-class>
* <init-param>
* <param-name>enconding</param-name>
* <param-value>UTF-8</param-value>
* </init-param>
* </filter>
* <filter-mapping>
* <filter-name>UTFFilter</filter-name>
* <url-pattern>/*</url-pattern>
* </filter-mapping>
* -------------------------------------------------
* filterName 对应web.xml 中filter-name
* value 对应web.xml 中 url-pattern
* servletNames 是指定那个servlet的name
*/
@WebFilter(filterName="UTFFilter",value="/*",servletNames={"Test"})
public class UTFFilter implements Filter{
@Override
public void destroy() {
System.out.println("======销毁======");
}
@Override
public void doFilter(ServletRequest req, ServletResponse res,
FilterChain chain) throws IOException, ServletException {
// 设置编码方式
req.setCharacterEncoding("UTF-8");
chain.doFilter(req, res);
}
@Override
public void init(FilterConfig config) throws ServletException {
System.out.println("======初始化=====");
}
}
登陆成后的页面
login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
欢迎 ${username}
</body>
</html>
强制登陆
package com.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
@WebFilter("/*")
public class LoginFilter implements Filter{
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest req, ServletResponse res,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest)req;
HttpSession session = request.getSession();
// 获取登陆用户名
String username = (String)session.getAttribute("username");
// 获取请求的uri
String uri = request.getRequestURI();
System.out.println("username:"+username+"==========");
if(username != null){
chain.doFilter(request, res);
}else if(uri.contains("/login")){
chain.doFilter(request, res);
}else{
System.out.println("===else====");
request.getRequestDispatcher("/index.jsp").forward(req, res);
}
}
@Override
public void init(FilterConfig arg0) throws ServletException {
}
}
这里需要把上面servlet中的Login 修改下 session作用域
// 设置作用域
req.getSession().setAttribute("username", username); // 加上这句
//req.setAttribute("username", username); 注释掉
上传文件
- 上传文件的servlet
-
package com.action; import java.io.IOException; import java.util.UUID; import javax.servlet.ServletException; import javax.servlet.annotation.MultipartConfig; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.Part; @WebServlet("/upload") @MultipartConfig public class Upload extends HttpServlet{ @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // 获取文件部件 part Part part = req.getPart("upfile"); String name = part.getHeader("content-disposition"); System.out.println(name); System.out.println("partName:"+part.getName()); // 上传路径 String root = req.getServletContext().getRealPath("/upload"); System.out.println("root:"+root); // 后缀名 String str = name.substring(name.lastIndexOf("."),name.length()-1); System.out.println("str:"+str); // 重命名 String filename = root + "\\"+UUID.randomUUID().toString()+str; part.write(filename); } }修改login.jsp页面 ，如下
-
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> 欢迎 ${username} <br/> <form action="upload" method="post" enctype="multipart/form-data"> <input type="file" name="upfile"><br/> <input type="submit" value="上传"> </form> </body> </html>此时上传就可以了
写的不是很详细,只是粗略的进行了下测试
如果不足，多多指导。
时间： 2024-10-30 01:39:28