Databases
StackOverflow2013
Postsdbo
POwhy the ArrayList is Returning empty strings [] [] []?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POwhy the ArrayList is Returning empty strings [] [] []?
    primarykey
    data
    text
    <p>this is my DB enquiry function</p> <pre><code> public static List&lt;UserPass&gt; selectAllUser() { ConnectionPool pool = ConnectionPool.getInstance(); Connection connection = pool.getConnection(); PreparedStatement ps = null; ResultSet rs = null; List&lt;UserPass&gt; usersPass = new ArrayList&lt;UserPass&gt;(); String query = "select * from UserPass"; try{ ps = connection.prepareStatement(query); rs = ps.executeQuery(); while(rs.next()){ UserPass users = new UserPass(); users.setUserName(rs.getString("user_name")); usersPass.add(users); } return usersPass; </code></pre> <p>and this is my UserPass object get function</p> <pre><code> public ArrayList&lt;UserPass&gt; getusernames(){ return usernames; } </code></pre> <p>my servlet dopost is simply this </p> <pre><code> request.setAttribute("users", UserPassDb.selectAllUser()); String forward = "/testpage.jsp"; RequestDispatcher view = request.getRequestDispatcher(forward); view.forward(request, response); </code></pre> <p>and my display jsp page is </p> <pre><code> &lt;form action="TestServlet" method="post"&gt; &lt;input type="submit"&gt; &lt;/form&gt; &lt;c:forEach var="user" items="${users}"&gt; &lt;c:out value="${user.usernames}"/&gt; &lt;/c:forEach&gt; </code></pre> <p>UserPass Class </p> <pre><code> /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package business; import java.io.Serializable; import java.util.ArrayList; /** * * @author One */ public class UserPass implements Serializable { public String username; public String password; public ArrayList&lt;UserPass&gt; usernames; public UserPass(){ this.username =""; this.password =""; this.usernames = new ArrayList&lt;UserPass&gt;(); } public void setUserName(String username) { this.username = username; } public String getUserName(){ return username; } public ArrayList&lt;UserPass&gt; getusernames(){ return usernames; } public void setusernames(ArrayList&lt;UserPass&gt; a){ this.usernames = a; } } </code></pre> <p>tried changing this it tells me property doesn't exist when it does as far as i understand. am sure am wrong</p> <p>Thanks in advance</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USTrackmeifYouCan
    1. USTrackmeifYouCan
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload