javascript - 尝试读取 JSP 时出错(500 内部服务器错误)

Question

我正在添加用户登录我的网站的功能。我在开发登录页面的用户界面时遇到一些困难。我收到错误

Error (500 Internal Server Error) while attempting to read 'webAPIs/logonAPI.jsp?email=user1@gmail.com&password=123'

当我在数据库中输入正确的用户凭据时。当我在浏览器本地运行 logonAPI.jsp 并将凭据添加到 URL 中时，它显示了正确的信息。但是，它不适用于我的用户界面。

这是我的代码。

用户界面页面:

var logon = {};

logon.UI = function (id) {
    var content = `
        <div class='logon'>
            <br/>
            Email Address: <input type="text" id="email"/>
            &nbsp;
            Password: <input type="password" id="password"/>
            &nbsp;
            <input type="button" value="Enter" onclick="logon.findById('email', 'password', 'msgArea')"/>
            <br/> <br/>
            <div id="msgArea"></div> 
        </div>
    `;
    document.getElementById(id).innerHTML = content;
}

logon.findById = function (email, password, targetId) {

    var contentDOM = document.getElementById(targetId);
    contentDOM.innerHTML = "";
    var logonEmail = escape(document.getElementById(email).value);
    var logonPassword = escape(document.getElementById(password).value);

    var logonUrl = "webAPIs/logonAPI.jsp?email=" + logonEmail + "&password=" + logonPassword;

    ajax2({
        url: logonUrl,
        successFn: success,
        errorId: targetId
    }); 

    function success(obj) {
        if (obj.webUserList[0] === null) {
            contentDOM.innerHTML = "Email + Password incorrect.";
        }
        else {
            contentDOM.innerHTML = "You have logged on.";
        }
    }
}

登录 API:

<%@page contentType="application/json; charset=UTF-8" pageEncoding="UTF-8"%> 

<%@page language="java" import="dbUtils.*" %>
<%@page language="java" import="model.webUser.*" %> 
<%@page language="java" import="view.WebUserView" %> 
<%@page language="java" import="com.google.gson.*" %>

<%

    // default constructor creates nice empty StringDataList with all fields "" (empty string, nothing null).
    StringData list = new StringData();

    String email = request.getParameter("email");
    String password = request.getParameter("password");

    if (email == null || password == null) {
        list.errorMsg = "Cannot search for user - 'email & password' must be supplied";
    } 
    else {

        DbConn dbc = new DbConn();
        list.errorMsg = dbc.getErr(); // returns "" if connection is good, else db error msg.

        if (list.errorMsg.length() == 0) { // if got good DB connection,

            System.out.println("*** Ready to call logonAPI");
            list = DbMods.logonFind(email, password, dbc); 
            if(list == null){    
            }
            else{
                session.setAttribute("webUser", list);
            }
        }
        dbc.close(); // EVERY code path that opens a db connection, must also close it - no DB Conn leaks.
    }
    // This object (from the GSON library) can to convert between JSON <-> POJO (plain old java object) 
    Gson gson = new Gson();
    out.print(gson.toJson(list).trim());
%>

DbMods 类

package model.webUser;

import dbUtils.DbConn;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class DbMods {

    public static StringDataList findById (DbConn dbc, String id) {

        StringDataList sdl = new StringDataList();
        try {
            String sql = "SELECT web_user_id, user_email, user_password, membership_fee, birthday, image, "
                    + "web_user.user_role_id, user_role_type "
                    + "FROM web_user, user_role WHERE web_user.user_role_id = user_role.user_role_id "
                    + "AND web_user_id = ?";

            PreparedStatement stmt = dbc.getConn().prepareStatement(sql);

            // Encode the id (that the user typed in) into the select statement, into the first 
            // (and only) ? 
            stmt.setString(1, id);

            ResultSet results = stmt.executeQuery();
            if (results.next()) { // id is unique, one or zero records expected in result set
                sdl.add(results);
            }
            results.close();
            stmt.close();
        } catch (Exception e) {
            StringData sd = new StringData();
            sd.errorMsg = "Exception thrown in WebUserView.getUserById(): " + e.getMessage();
            sdl.add(sd);
        }
        return sdl;

    } // getUserById

    public static StringData logonFind(String email, String pw, DbConn dbc) {
            StringData foundData = new StringData();
            if ((email == null) || (pw == null)) {
                foundData.errorMsg = "Programmer error in model.webUser.DbMods.logonFind: email and pw must be both non-null.";
                return foundData;
            }
            try {
                String sql = "SELECT web_user_id, user_email, user_password, membership_fee, birthday, image,"
                        + "web_user.user_role_id, user_role_type "
                        + "FROM web_user, user_role "
                        + "WHERE web_user.user_role_id = user_role.user_role_id "
                        + "AND user_email = ? and user_password = ? ";
                PreparedStatement pStatement = dbc.getConn().prepareStatement(sql); // this compiles the SQL

                // Encode user supplied values into the ?s of the prepared statement.
                pStatement.setString(1, email); // replace 1st question mark
                pStatement.setString(2, pw);    // replace 2nd question mark

                ResultSet results = pStatement.executeQuery();  // Get the result set - expecting 1 or 0 records, 
                                                                // because user_email must be unique within the table.
                if (results.next()) {
                    // Record found in database, credentials are good.
                    return new StringData(results);
                } else {
                    // Returning null means that the username / pw were not found in the database
                    return null;
                }
            } catch (Exception e) {
                foundData.errorMsg = "Exception in model.webUser.DbMods.logonFind(): " + e.getMessage();
                System.out.println("******" + foundData.errorMsg);
                return foundData;
            }
        } // logonFind

} // class

这是输入正确的凭据后单击“提交”时控制台中显示的错误消息

HTTP Status 500 - Unable to compile class for JSP:
type Exception report

message Unable to compile class for JSP:

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: 27 in the jsp file: /test6/webAPIs/logonAPI.jsp
DbMods cannot be resolved
24:         if (list.errorMsg.length() == 0) { // if got good DB connection,
25: 
26:             System.out.println("*** Ready to call logonAPI");
27:             list = DbMods.logonFind(email, password, dbc); 
28:             if(list == null){    
29:             }
30:             else{


Stacktrace:
    org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:103)
    org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:366)
    org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:468)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:378)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
    org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:657)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)

Answer 1

您需要使用静态导入类:

<%@page import="static model.webUser.DbMods"%>