Questions[jsp]

I come across an error that I am not able to solve, the fact is that after making some example codes and testing them with the Tomcat 10 server that I have installed, they work fine but in the dynamic web project, specifically the web.xml file gives me error, I attach a photo and code in case someone knows how to solve it, although I have tried to change j2ee for javaee and the label continues to give me an error.

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.5" 
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>otro</display-name>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>
</web-app>

I have tried to put 2.4 and the error disappears on line 2 version="2.5" but the file continues with the error and also the error continues, thank you very much in advance.

All the best

I am trying to iterate through a list of 8 specific items. I would need to show the first three, but it has not been very clear to me how to do it.

I appreciate the help.

<c:forEach begin="0" step="1" end="3" items="${Articulos}">
                <div>${item.idArticulo}</div>
                <a class="destacado my-2" style="word-break: break-word;" 
                  href="${item.url}">${item.nombre}</a> 
</c:forEach>

I know it's not right but at least it serves to explain my doubt.

In the list of articles, I have 8 articles, I want it to show me only 3 articles.

I have a small program that makes a query to the sql server from which it extracts data, but I can't get it to show me each corresponding data.

The output I get right now is this:

Id Student, Name and phone is fine but the name of the course is the one that I can't make it come out right, the correct output would be:

1. 1, VICTOR, 2212134, FIRST THAT
2. 2, PACO, 984747321, FIRST THAT
3. 3, PEPE, 964321345, SECOND THAT

On the one hand I have a dataStudents.java:

   public class datosAlumnos 
{
Connection miconexion;
String cadsql;

    public datosAlumnos() {
         miconexion=MySQL_Util.Conectar("localhost","root","", "ciclosfp");             
    }
    
    public ResultSet getResultado() {
        
       cadsql ="select a.ID, a.NOMBRE, a.TELEFONO, cursos.NOMBRE from alumnos a, cursos "
               + "where cursos.id = a.CURSO;";
        
        ResultSet rset=
                 MySQL_Util.Sel_Consulta(miconexion, cadsql);
        return rset;
    }
}

And a dataCourses.java:

    public class datosCursos 
{
Connection miconexion;
String cadsql;
private ResultSet rsIDAlum;
private ResultSet rsFCurso;

    public datosCursos() {
         miconexion=MySQL_Util.Conectar("localhost","root","", "ciclosfp");             
    }

       public ResultSet getRsIDAlum() {
        rsIDAlum=MySQL_Util.Sel_Consulta(miconexion, "select * from alumnos");
        return rsIDAlum;
    }

    public void setRsIDAlum(ResultSet rsIDAlum) {
        this.rsIDAlum = rsIDAlum;
    }
    
    
    public ResultSet getRsFCursos() {
        try
        {
        String cadsql2 ="select cursos.nombre from cursos inner join alumnos on cursos.ID=alumnos.ID where alumnos.ID="+rsIDAlum.getString("ID");
            rsFCurso=(MySQL_Util.Sel_Consulta(miconexion, cadsql2));
       
        }
        catch (Exception e)
        {
            rsFCurso=null;
        }
        return rsFCurso;
    }

    public void setRsFCursos(ResultSet rsFCurso) {
        this.rsFCurso = rsFCurso;
    }

}

and the index to display:

    <h1><h:outputText value="Datos de los alumnos:"/></h1>
          
            <h:dataTable border="1" value="#{datosAlumnos.resultado}"
                         var="fila">
                <h:column>
                    <f:facet name="header">
                        <h:outputText value="Id Alumno"/>
                    </f:facet>
                    <h:outputText value="#{fila.ID}"/>
                </h:column>  
                <h:column>
                    <f:facet name="header">
                        <h:outputText value="Nombre Alumno"/>
                    </f:facet>
                    <h:outputText value="#{fila.NOMBRE}"/>
                </h:column>  
                <h:column>
                    <f:facet name="header">
                        <h:outputText value="Telefono"/>
                    </f:facet>
                    <h:outputText value="#{fila.TELEFONO}"/>
                </h:column> 
                     <h:column>
                    <f:facet name="header" >
                        <h:outputText value="Nombre Curso"/>
                    </f:facet>
                    <h:dataTable value="#{datosCursos.rsFCursos}" var="forma" > 
                        <h:column>
                            <h:outputText value="#{forma.nombre}"/>
                        </h:column>                   
                    </h:dataTable>                            
                </h:column>
            </h:dataTable>
        </body>
    </html>
</f:view>

The thing is that the query of the courses shows the result in the 3 tables of the students and I have tried everything and I cannot make it work. I can't find information on whether aliases can be used in jsp for the tables, since there are two tables that have the same name (name[students] and name[courses]) I can't just put row.name because it takes the name of the students twice.

Update: I have modified the DataCurso.java file since I think this is the correct path but now in Course Name it does not show me any data.

I have an old JSP project for which I use eclipse as the ide.

Once everything is configured and I test that it works, I want it to start in another path other than the default path that Eclipse launches.

when I launch the project, it runs in http://localhost:8080/miapp/. But I want that when executing, the same is executed inhttp://localhost:8080/miapp/menu/mijsp.jsp

As a bonus, I want to pass parameters to it so that it looks like this:http://localhost:8080/miapp/menu/mijsp.jsp?param1=aaa?param2=bbb

When I run it, and type the path by hand it goes to that page, so the project works.

The folder structure of my project is like this:

I suppose that I have to modify something in the Deployment Descriptor, but for a change I can't find anything that tells me what to modify or how...

Extra bonus: if someone knows how to modify the route so that where it says myapp they can change it, they get an extra coffee...

I'm working on a project and I need to know if the file type input has something to insert it into the DB, I was trying to validate if it was different from null, but even if I don't put any file, it enters as if it were different from null.

iPart part = request.getPart("aFoto");
        if (part != null) {
            InputStream inputStream = part.getInputStream();
            c.setFoto(inputStream);
        }