为什么在servlet中无法获取到参数? 急！
我贴一下主要的代码
登陆页面
public class Login extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) {
try {
//中文乱码
response.setContentType("text/html;charset=gb2312");
PrintWriter pw=response.getWriter();
//返回登陆界面
pw.println("<html>");
pw.println("<body>");
//得到error信息
String info=request.getParameter("info");
if (info!=null) {
pw.println("<h1>你的用户名或是密码错误</h1>");
}
pw.println("<h1>登陆界面</h1>");
pw.println("<form action=Logincl method=post>");
pw.println("用户名:<input type=text name='username' /><br/>");
pw.println("密码:<input type=password name=password /><br/>");
pw.println("<input type=submit value=login /><br/>");
pw.println("</form>");
pw.println("</body>");
pw.println("</html");
} catch (Exception e) {
e.printStackTrace();
}
}
}
public class Logincl extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) {
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
// 业务逻辑
try {
request.setCharacterEncoding("GBK");
// 接收用户名和密码
String username = request.getParameter("username");
String pwd = request.getParameter("password");
// 连接数据库
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection(
"jdbc:oracle:thin:@localhost:1521:sjbitdb", "epet", "bdqn");
pstmt = conn
.prepareStatement("select * from master where loginname=? and pwd=?");
pstmt.setString(1, username);
pstmt.setString(2, pwd);
rs = pstmt.executeQuery();
// 验证
if (rs.next()) {
// 合法（跳转到welcome）
response.sendRedirect("Welcome?username="+username+"&pwd="
+ pwd);
System.out.println("username"+username);//此处在控制台显示 仍然能够打印出 张三
} else {
// 不合法
response.sendRedirect("Login");// 写你要跳到的servlet的url
}
} catch (Exception e) {
e.printStackTrace();
}finally{
try {
if (rs!=null) {
rs.close();
}
if (pstmt!=null) {
pstmt.close();
}
if (conn!=null) {
conn.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response) {
doGet(request, response);
}
}
public class Welcome extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) {
// 业务逻辑
try {
request.setCharacterEncoding("GBK");
String username=request.getParameter("username");
System.out.println("username"+username);//此处在控制台显示为空
String pwd = request.getParameter("pwd");
response.setContentType("text/html;charset=gbk");
PrintWriter pw = response.getWriter();
pw.println("welcome!" + "用户名" + username + "密码" + pwd);
} catch (Exception e) {
}}
public void doPost(HttpServletRequest request, HttpServletResponse response) {
doGet(request, response);
}
}
http://localhost:8080/Servlet1/Welcome?username=%20&pwd=888888
[解决办法]
编码问题，你把你浏览器的设置为GBK看看。
[解决办法]
获取参数的时候将编码格式改为UTF-8 或GBK或GB2312 试试。
String username= new String(request.getParameter("username").getBytes("ISO-8859-1"),"UTF-8");
这样在欢迎页面应该可以看到你输入的中文字符了。
[解决办法]
要是乱码，最起码也得有乱码输出来吧 觉得不是乱码问题！
[解决办法]
撸主说输出是null？ Welcome页面在输出一遍 ，在控制台看看是啥？
[解决办法]
"Welcome?username="+username+"&pwd=" + pwd 登陆处理页面打印出来看看是啥？
[解决办法]
