I have a ui tag select
<s:select list="studentList" name="selectedstudent" listKey="studentID"
listValue="studentName" headerKey="0"
headerValue="--All Student--" theme="simple"></s:select>
in java code i have selectedstudent returns let say 4 how can I get the name of student in java.
You can get the name by id in selectedstudent. For this purpose if you don't have a students list in your action, you should load them from database. Otherwise searching a Student object by id would return a name if you provide a getter for the object. Keep in mind that you have already specified a listValue as studentName. This value should be taken from a Student and thus a list should be List<Student> as well.
If your studentList is in session you can retrieve student name as follow (your code may be different):
List<Student> studentList = (List<Student>)ActionContext.getContext().getSession().get("studentList");
//You should ovveride equals(and hashCode) to point the Student equality to studentID
//You should also check if studentList.indexOf(selectedstudent) != -1
Student student = studentList.get(studentList.indexOf(selectedstudent));
String studentName = student.getStudentName();
Business layer
Student.java (model)
public class Student {
//Getter and Setter Method.
private String id;
private String name;
public Student(String id, String name) {
this.id = id;
this.name = name;
}
}
struts.xml
<action name="list_action" class="controller.ListAction">
<result name="success">struts_select.jsp</result>
</action>
package controller;
ListAction.java
private List<Student> student_list = new ArrayList<Student>();//Getter and Setter
#Override
public String execute() throws Exception {
//do your stuff
//list collect from database.
student_list=(List<Student>) criteria.list();
}
struts_select.jsp
<s:select label="Student List"
listKey="id" //use your Student.java member variable of id signature
listValue="name" //use your Student.java member variable of name signature
headerKey="0" headerValue="Select student Name"
list="s"
name="student_info" />
Related
I want to pass a session value as a hidden form value to an action class.
I have seen several examples but nothing worked for me; I get a null in the action.
Update.jsp:
<s:hidden name="name" value="%{#session.sname}" />
<s:property value="#session.sname"></s:property>//works fine and printing username
User name is stored in session. I want to send this name to action class but I am unable to send.
UpdateAction.java:
public class UpdateAction extends ActionSupport {
String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public string execute() {
System.out.println("Username"+name);//getting null value
}
}
You should try:
<s:hidden value="%{#session['sname']}" name="aName"></s:hidden>
I have a base view model with an Id property of type object (so I can have it be an int or a Guid) like so:
public abstract class BaseViewModel
{
public virtual object Id { get; set; }
}
And the view models thus derive from this
public class UserViewModel : BaseViewModel
{
public string FirstName { get; set; }
public string LastName { get; set; }
}
My HTML then is rendered as:
<input id="Id" name="Id" type="hidden" value="240" />
<input id="FirstName" name="FirstName" type="text" value="John" />
<input id="LastName " name="LastName " type="text" value="Smith" />
And when submitted to the MVC action:
[HttpPost]
public ActionResult EditUser(UserViewModel model)
{
...code omitted...
}
The values for the model properties are:
Id: string[0] = "240"
FirstName: string = "John"
LastName: string = "Smith"
My question is, why am I getting a one item string array as the value for Id, rather than just a string? And is there a way to change this behavior? It causes problems when I try to parse it into the expected type.
I ended up solving this with a custom model binder that handles the "Id" object property as a special case:
public class CustomModelBinder : DefaultModelBinder
{
protected override void BindProperty(ControllerContext controllerContext, ModelBindingContext bindingContext, System.ComponentModel.PropertyDescriptor propertyDescriptor)
{
// apply the default model binding first to leverage the build in mapping logic
base.BindProperty(controllerContext, bindingContext, propertyDescriptor);
// since "Id" is a special property on BaseViewModel of type object,
// we need to figure out what it should be and parse it appropriately
if (propertyDescriptor.Name == "Id" && propertyDescriptor.PropertyType == typeof(object))
{
// get the value that the default binder applied
var defaultValue = propertyDescriptor.GetValue(bindingContext.Model);
// this should be a one element string array
if (defaultValue is string[])
{
var defaultArray = defaultValue as string[];
// extract the first element of the array (the actual value of "Id")
var propertyString = defaultArray[0];
object value = propertyString;
// try to convert the ID value to an integer (the most common scenario)
int intResult;
if (int.TryParse(propertyString, out intResult))
{
value = intResult;
}
else
{
// try to convert the ID value to an Guid
Guid guidResult;
if (Guid.TryParse(propertyString, out guidResult)) value = guidResult;
}
// set the model value
propertyDescriptor.SetValue(bindingContext.Model, value);
}
}
}
}
The issue is with typing your id property as object -- not sure how the default binding is supposed to work here, but since an object is potentially anything -- like a complex object with multiple properties itself -- perhaps it attempts to dump all of the properties it finds there into an array?
If the Id is not always going to be an integer, I'd suggest typing this as string, since the model-binding mechanism should have no problem mapping virtually anything sent over HTTP as string, so:
public abstract class BaseViewModel
{
public virtual string Id { get; set; }
}
Is it possible to access the display name of a parameter in the controller? for example, say I defined a parameter as
public class Class1
{
[DisplayName("First Name")]
public string firstname { get; set; }
}
I now want to be able to access the display name of firstname in my controller. Something like
string name = Model.Class1.firstName.getDisplayName();
Is there a method like getDisplayName() that I can use to get the display name?
First off, you need to get a MemberInfo object that represents that property. You will need to do some form of reflection:
MemberInfo property = typeof(Class1).GetProperty("Name");
(I'm using "old-style" reflection, but you can also use an expression tree if you have access to the type at compile-time)
Then you can fetch the attribute and obtain the value of the DisplayName property:
var attribute = property.GetCustomAttributes(typeof(DisplayNameAttribute), true)
.Cast<DisplayNameAttribute>().Single();
string displayName = attribute.DisplayName;
Found the answer at this link. I created an Html helper class, added its namespace to my view web.config and used it in my controller. All described in the link
Display name for Enum is like this
Here is example
public enum Technology
{
[Display(Name = "AspNet Technology")]
AspNet,
[Display(Name = "Java Technology")]
Java,
[Display(Name = "PHP Technology")]
PHP,
}
and method like this
public static string GetDisplayName(this Enum value)
{
var type = value.GetType();
var members = type.GetMember(value.ToString());
if (members.Length == 0) throw new ArgumentException(String.Format("error '{0}' not found in type '{1}'", value, type.Name));
var member = members[0];
var attributes = member.GetCustomAttributes(typeof(DisplayAttribute), false);
if (attributes.Length == 0) throw new ArgumentException(String.Format("'{0}.{1}' doesn't have DisplayAttribute", type.Name, value));
var attribute = (DisplayAttribute)attributes[0];
return attribute.GetName();
}
And your controller like this
public ActionResult Index()
{
string DisplayName = Technology.AspNet.GetDisplayName();
return View();
}
for class property follow this step
public static string GetDisplayName2<TSource, TProperty> (Expression<Func<TSource, TProperty>> expression)
{
var attribute = Attribute.GetCustomAttribute(((MemberExpression)expression.Body).Member, typeof(DisplayAttribute)) as DisplayAttribute;
return attribute.GetName();
}
and call this method in your controller like this
// Class1 is your classname and firstname is your property of class
string localizedName = Testing.GetDisplayName2<Class1, string>(i => i.firstname);
Hey guys I'm having some problems with a project that I'm doing :/
I have this code
public class ListaAlumnoAction {
private List<Alumno> alumnos;
public String execute(){
String camino="success";
EntityManager em= Utilitario.getInstance().getEntityManager();
Query query=em.createQuery("Select o From Alumno o");
alumnos=query.getResultList();
return camino;
}
public List<Alumno> getAlumnos() {
return alumnos;
}
public void setAlumnos(List<Alumno> alumnos) {
this.alumnos = alumnos;
}
}
This method gives me a list of students. But in this case I just want 1 student, searching by code for example or by name and last name. The thing is I don't know what kind of tools use for this purpose.
Thanks in advanced.
For searching the student by specified input criteria, you are in need of passing the required input from the page to the action class. And need to modify the query which will search the student record by mentioned name or last name or desired input.
For example, assume student name is the input criteria
To pass the student name from the page:
<s:form>
......
<s:textfield name="studentName" label="Student Name"></s:textfield>
<s:submit value="Search" name="submit" action="ListaAlumnoAction"/>
......
</s:form>
Here the studentName will be the input for search operation and ListaAlumnoAction is action which will fired when Search button clicked.
To get the Student Name in the Action Class:
public class ListaAlumnoAction {
private List<Alumno> alumnos;
/* Please note both the text filed name in the page and attribute should be same "studentName" */
private String studentName;
public String execute(){
String camino="success";
EntityManager em= Utilitario.getInstance().getEntityManager();
// "name" variable will hold the studentName
String name = getStudentName();
// Modify the query, by passing the name if it is not null
Query query=em.createQuery("Select o From Alumno o");
alumnos=query.getResultList();
return camino;
}
public List<Alumno> getAlumnos() {
return alumnos;
}
public void setAlumnos(List<Alumno> alumnos) {
this.alumnos = alumnos;
}
// getter and setter for the studentName
public String getStudentName(){
return studentName;
}
public void setStudentName(String studentName){
this.studentName = studentName;
}
}
I am facing a problem in Struts2, In my sample application I have Array of objects (Say person name) , I need to display these names as a editable text fields , I am using Iterators for this , I am successful in diaplying, But When I cange the same value and submit the form. I am getting the entire array which holds null value.
Say for Exaple in my form bean I have a property
Name [] names;
In my JSP I have the iterator as
If there are 3 names then I can get these names on the UI if I can initialized them with some dummy value but when I edit and sumbit, then "names" array is not getting updated. Please help me in this regard
In Struts2, when you need to repopulate the list of bean items, you need to refer them through indices. Please refer the example below:
Bean class:
public class Person {
private int id;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
Action class:
public class PersonAction extends ActionSupport {
private List<Person> persons;
public List<Person> getPersons() {
return persons;
}
public void setPersons(List<Person> persons) {
this.persons = persons;
}
//Initial Load method
#Override
public String execute() {
persons = new ArrayList<Person>();
int alpha = 65;
for(int i = 0; i < 3 ; i++) {
Person person = new Person();
person.setId(i);
person.setName(String.valueOf((char)alpha++));
persons.add(person);
}
return SUCCESS;
}
//Function that handles the form submit
public String updatePerson() {
for(Person person : persons) {
System.out.println(person.getId() + ":" + person.getName());
}
return SUCCESS;
}
}
Page:
<s:form action="doUpdate">
<s:iterator value="persons" status="stat" var="person">
<s:textfield value="%{#person.name}" name="persons[%{#stat.count}].name"/><br/>
</s:iterator>
<s:submit value="Submit"/>
</s:form>
When you submit the above form, the url would look like doUpdate?persons[0].name=A1&persons[1].name=B1&persons[2].name=C1. Similarly if you need to update id of the first person object, you will append persons[0].id=3 to the url using form. In the <s:textfield value="%{#person.name}" name="persons[%{#stat.count}].name"/>, you tell that the predefined value is person's name, for each object. The name attribute is to set the rendered html input element; the name which will be referenced in the url when the form is submitted. You will get a clear idea if you look into the generated html.
Use the iterator tag of struts2, if list is not empty then use :
<s:iterator value="names" status="namesStatus">
<s:property/><br/>
</s:iterator>