Question

我正在实现一个JSF应用程序，其中用户提供的凭据通过查看MySQL数据库表进行验证，如果找到它们，则客户端和服务器之间的HTTP会话启动并且“欢迎” “页面是根据他/她的请求返回的。 “欢迎”页面包含一个注销按钮，当我点击它时，什么都不做（我检查了HTTP流量以确保它）。

<h:commandButton value="Logout" type="submit" action="#{logoutBean.terminate}"/>

注销按钮与处理注销过程的托管bean相关（即终止会话并返回起始页）。终止会话并返回起始页面的功能如下：

public String terminate() {
    System.out.println("Here!"); //for debug
    FacesContext fc = FacesContext.getCurrentInstance();
    HttpSession session = 
        (HttpSession) fc.getExternalContext().getSession(false);
    try {
        session.invalidate();
    } catch(IllegalStateException isEx) {
        isEx.printStackTrace();
    }

    return "index";
}

即使消息Here!也未在控制台中查看。

更具体地说，让我发布下面的完整代码。

我的welcome.xhtml页面：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
    <title>Admin's page</title>
</head>

<body>
    <h2>Welcome admin!</h2>
    <p>You are successfully logged in</p> <br/>
    <h:commandButton value="Logout" type="submit" action="#{logoutBean.terminate}"/>
</body>

</html>

我的LogoutBean.java文件（处理退出请求）：

package loginbean;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpSession;

@ManagedBean(name="logoutBean")
@RequestScoped
public class LogoutBean {
    private String errorMsg = null;

    public LogoutBean() { }

    public String getErrorMsg() {
        return errorMsg;
    }

    public void setErrorMsg(String errorMsg) {
        this.errorMsg = errorMsg;
    }

    public String terminate() {
        System.out.println("Here!");
        FacesContext fc = FacesContext.getCurrentInstance();
        HttpSession session = 
            (HttpSession) fc.getExternalContext().getSession(false);
        try {
            session.invalidate();
        } catch(IllegalStateException isEx) {
            isEx.printStackTrace();
        }

        return "index";
    }
}

我的首页（index.xhtml）

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" 
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:h="http://java.sun.com/jsf/html">

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
    <title>Login</title>
</head>

<body>
    <h2>Login</h2>
    <h:outputText value="#{loginBean.errorMsg}"
    rendered="#{loginBean.errorMsg != null}"
    style="color:red;"/>

    <h:form>
        User Name: <h:inputText id="userName" value="# {loginBean.userName}"/>
        <br/>
        Password: <h:inputSecret id="password" value="#{loginBean.password}"/>
        <br/>
        <h:commandButton value="Submit" type="submit" action="#{loginBean.validate}"/>
        <h:commandButton value="Reset" type="reset"/>
    </h:form>
</body>

</html>

和我的LoginBean.java（处理登录请求）

package loginbean;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpSession;

import java.sql.*;

@ManagedBean(name="loginBean")
@RequestScoped
public class LoginBean {
private String userName = null;
private String password = null;
private String errorMsg = null;

public LoginBean() {}

public String getUserName() {
    return userName;
}

public void setUserName(String userName) {
    this.userName = userName;
}

public String getPassword() {
    return password;
}

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

public String getErrorMsg() {
    return errorMsg;
}

public void setErrorMsg(String errorMsg) {
    this.errorMsg = errorMsg;
}

public String validate() {
    try {
        Connection conn = DriverManager.getConnection(
                "jdbc:mysql://localhost:3306/dbname?useSSL=false", 
                "rootName", "aPassword");
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("select name, password from admins;");

        // Look for the credentials into the table.
        while (rs.next()) {
            if (rs.getString("name").equals(userName) 
                && rs.getString("password").equals(password)) {
                errorMsg = "null";

                // Start a session with the client.
                FacesContext fc = FacesContext.getCurrentInstance();
                HttpSession session = (HttpSession)    fc.getExternalContext().getSession(true);
                System.out.println("Session ID = " + session.getId());
                // Return the "welcome.xhtml" page.
                return "welcome";
            }
        }
    } catch(SQLException sqlEx) {
        System.out.println("Error code: " + sqlEx.getErrorCode());
    }
    errorMsg = "Invalid user. Please try again";
    return null;
}

}

我认为没有必要发布我的web.xml，因为这对于这样的应用来说非常明显。

有人可以帮我正确实施这样的退出流程吗？

JSF应用程序中的功能失调的注销按钮

0 个答案: