Question

我正在做一个项目，搜索我的数据库中的特定成员，搜索他的 memberId ，然后显示所选信息，但我的Java类Setter出现问题（不确定是否真的出问题）因为我一直收到来自catch的错误消息（Exception ex）

javax.el.PropertyNotFoundException：类'Project.Members'没有属性'FirstName'。

你能帮我弄清楚我的代码出了什么问题吗？

这是我的servlet代码：

public class SearchAMember extends HttpServlet {


protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();
    Connection con = null;
    PreparedStatement stmt = null;
    ResultSet rs = null;
    String query = "SELECT memberId, FirstName FROM members WHERE memberId = ?";
    try {
        out.println("<html>");
        out.println("<head>");
        out.println("<title>Servlet SelectDemo</title>");
        out.println("</head>");
        out.println("<body>");

        try {
            Class.forName(Connect.DRIVER);
            con = DriverManager.getConnection(Connect.CONNECTION_STRING,
                    Connect.USERNAME, Connect.PASSWORD);

            stmt = con.prepareStatement(query);
            int findId = Integer.parseInt(request.getParameter("id"));
            stmt.setInt(1, findId);
            rs = stmt.executeQuery();

            Members std;
            if (rs.next()) {
                std = new Members();
                std.setMemberId(rs.getInt("memberId"));
                std.setFirstName(rs.getString("FirstName"));
                request.setAttribute("Members", std);
                RequestDispatcher rd = request.getRequestDispatcher("/DisplayAllMembers.jsp");
                rd.forward(request, response);
            } else {
                out.println("No record found...");
            }

        } catch (ClassNotFoundException ex) {
            out.println("Driver not found...");
        } catch (SQLException ex) {
            out.println("Failed connection or query...." + ex.getMessage());
        } catch (Exception ex) {
            out.println("Error.... " + ex.getMessage());
        } finally {
            try {
                con.close();
            } catch (SQLException ex) {
            }
        }
    } finally {
        out.println("</body>");
        out.println("</html>");
        out.close();
    }
}

/*<--HttpServlet Method was here-->*/
}

}

我的getter和setter的

和 Member.java 类：

公共班级成员{

private int memberId;
private String Username;
private String Password;
private String FirstName;
private String MiddleName;
private String LastName;
private String Address;
private String Email;
private int CurrPoints;

public String getAddress() {
    return Address;
}

public int getCurrPoints() {
    return CurrPoints;
}

public String getEmail() {
    return Email;
}

public String getFirstName() {
    return FirstName;
}

public String getLastName() {
    return LastName;
}

public String getMiddleName() {
    return MiddleName;
}

public String getPassword() {
    return Password;
}

public String getUsername() {
    return Username;
}

public int getMemberId() {
    return memberId;
}

public void setAddress(String Address) {
    this.Address = Address;
}

public void setCurrPoints(int CurrPoints) {
    this.CurrPoints = CurrPoints;
}

public void setEmail(String Email) {
    this.Email = Email;
}

public void setFirstName(String FirstName) {
    this.FirstName = FirstName;
}

public void setLastName(String LastName) {
    this.LastName = LastName;
}

public void setMiddleName(String MiddleName) {
    this.MiddleName = MiddleName;
}

public void setPassword(String Password) {
    this.Password = Password;
}

public void setUsername(String Username) {
    this.Username = Username;
}

public void setMemberId(int memberId) {
    this.memberId = memberId;
}

}

这也是我的 Jsp ：

<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
</head>
<body>
    <h1>Members Information</h1>
    Id: ${Members.memberId}&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
    Name: ${Members.FirstName}<br/>
</body>

问题出在我的 Members.java 类吗？我真的很无能为力了...请帮忙......

Answer 1

您应该尊重Java命名约定。变量始终以小写字母开头。属性也以小写字母开头。由于会员级代表一个会员，您也应该将其称为会员，而不是会员。

request.setAttribute("member", std);

public class Member {
    private String firstName;
    // ...
    public String getFirstName() {
        return this.firstName;
    }
}

Id: ${member.memberId}&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Name: ${member.firstName}<br/>

保持接收javax.el.PropertyNotFoundException：类'...'没有属性'...'

1 个答案: