StringUtil.java

public class StringUtil {
    public StringUtil(){}
    private String name;
    private String pwd;
    private String cue;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPwd() {
        return pwd;
    }
    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
    public String getCue() {
        if((name==null||name.equals(""))||(pwd==null||pwd.equals(""))){
            cue="請輸入用戶名或密碼！";
        }else{
            if(name.equals("admin")&&pwd.equals("123456")){
                cue="登錄成功！";
            }else {
                cue="登錄失??！<b>用戶名</b>或<b>密碼</b>不正確！";    
            }
        }
        return cue;
    }
    public void setCue(String cue) {
        this.cue = cue;
    }
    
}

index.jsp

<form action="result.jsp" method="post">
        <table>
            <tr>
                <td align="right">請輸入用戶名：</td>
                <td><input type="text" name="name" /></td>
            </tr>
            <tr>
                <td align="right">請輸入密碼：</td>
                <td><input type="password" name="pwd" /></td>
            </tr>
            <tr>
                <td colspan="2" align="center"><input type="submit" value="登錄"/></td>
            </tr>
        </table>
    </form>

result.jsp

    <%
        request.setCharacterEncoding("utf-8");
        String name= request.getParameter("name");
        String pwd = request.getParameter("pwd");
        
    %>
    <jsp:useBean id="strBean" class="com.count.StringUtil"></jsp:useBean>
    <jsp:setProperty property="name" name="strBean" value="<%=name %>"/>
    <jsp:setProperty property="pwd" name="strBean" value="<%=pwd %>"/>
    
    <table>
        <tr>
            <td align="right">提示信息：</td>
            <td>
                <jsp:getProperty property="cue" name="strBean"/>
            </td>
        </tr>
        <tr>
            <td align="center" colspan="2"><a href="index.jsp">【返回】</a></td>
        </tr>
    </table>

16.PNG