How to display “no result found” using arraylist in struts2

问题

Here I am firing some query ..and it displays record but what i want is if there is no record then it should display "no match/result found" .
I am using ArrayList in Struts2 . So can i be able to achieve it ? Please if anyone can make changes or suggest something that would be very helpful. I have searched solution for this but wasn't able to get relevant solution. Below I am posting my Action class and jsp page on which i want to display results.
Thanks in advance. :)

BookSearchAction.java

package org.entity;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.opensymphony.xwork2.ActionSupport;

public class BookSearchAction extends ActionSupport {

    Book book;

    List<Book> bookResultList;

    public Book getBook() {
        return book;
    }

    public void setBook(Book book) {
        this.book = book;
    }

    public List<Book> getBookResultList() {
        return bookResultList;
    }

    public void setBookResultList(List<Book> bookResultList) {
        this.bookResultList = bookResultList;
    }

    public BookSearchAction() {
        // TODO Auto-generated constructor stub
    }

    @Override
    public String execute() throws Exception {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/staff", "root", "siddheshkk");
            System.out.println("Driver Loaded");
            Statement stmt = con.createStatement();
            ResultSet rs = stmt
                    .executeQuery("select * from books12 where name like '%"
                            + book.getBookName() + "%'");
            bookResultList = new ArrayList<Book>();
            while (rs.next()) {
                bookResultList.add(new Book(rs.getString(1), rs.getInt(2)));
            }

            con.close();
        } catch (Exception e) {
            System.out.println(e);
        }

        return "success";
    }

}

success.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ taglib uri="/struts-tags" prefix="s"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Results</title>
</head>
<body>
    <h1>data retrieved successfully..</h1>
<h3>Here is the data: </h3><br>
    <table border="2">
    <th>
    <tr><td>Book Name</td><td>Cost</td></tr>
    </th>
    <s:iterator value="bookResultList">
        <s:iterator>
            <tr>
            <td><s:property value="bookName"/></td>
            <td><s:property value="bookCost"/></td>
            </tr>
        </s:iterator>

    </s:iterator>
    </table>
</body>
</html>

Anyone please help me :(

回答1:

You can use <s:if> and <s:else> tags of struts2 to check whether the list is empty or not, for example

<s:if test="%{bookResultList.size>0}">
  <table>
     <s:iterator value="bookResultList">
        <tr>      
          <td><s:property value="bookName"/></td>
          <td><s:property value="bookCost"/></td>                
       </tr>
    </s:iterator>
 </table>
 </s:if>
<s:else>
    <div> No data found</div>
</s:else>

In case Struts1.x version, you can use <logic:present> tag. Hope this helps.

来源：https://stackoverflow.com/questions/31279378/how-to-display-no-result-found-using-arraylist-in-struts2

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javascript

java

jsp

arraylist

struts2