B4J Question Class Explorer: Getting Methods and Properties

[Mashiane]

Hi

Is it possible to get all the methods and properties of a class?

As an Example, lets say I have a class named clsPerson with Method, Initialize, SetAge, GetAge and properties Age, Gender, MobilePhone.

How can I get these properies by reading the class via a loop?

For each prop as Property in clsPerson.Properties
    log(prop.Name)
next

for each meth as method in clsPerson.Methods
    log(meth.definition)
    log(meth.variables)
    for each v as variable in meth.variables
        log(v.name)
        log(v.type)    'boolean, string, datetime  
    next
next

Is there anything like this possible?

Anyone please advise?

 

[Erel]

You can use Java reflection APIs to get this information. It is not so simple and the APIs required to listing the available fields are not exposed in JavaObject or jReflection libraries.

 

[Daestrum]

Little example

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
    Dim theCode,inline As JavaObject
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    inline = Me
    MainForm = Form1
    MainForm.SetFormStyle("UNIFIED")
    MainForm.Show
    ' you need to know the name of the class contained in the jar
    ' (jarFile).(className) etc
    theCode.InitializeNewInstance("java.lang.String",Null)
    Dim s As String = theCode.RunMethod("getClass",Null)
    Dim l As List = inline.RunMethod("getMethods",Array(s.replace("class ","")))
    For Each item As String In l
        Log(item)
    Next
End Sub
#if java
import java.util.List;
import java.lang.reflect.Method;
import java.lang.reflect.Constructor;
import java.util.ArrayList;

public static List<String> getMethods(String cname) {
        List<String> li = new ArrayList<String>();
        Method[] methods = null;
        Class<?> c = null;
        try {
            c = Class.forName(cname);
            methods = c.getDeclaredMethods();
            System.out.println("Method count = " + methods.length);
            if (methods.length > 0 && methods != null){
                for (int a = 0 ; a < methods.length;a++){
                    li.add(methods[a].toString());
                }   
            } 
        } catch (ClassNotFoundException ex) {
            System.out.println("Class not found");
        }
        return li;
    }
#end if

Hope it helps.

 

[Mashiane]

Little example

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
    Dim theCode,inline As JavaObject
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    inline = Me
    MainForm = Form1
    MainForm.SetFormStyle("UNIFIED")
    MainForm.Show
    ' you need to know the name of the class contained in the jar
    ' (jarFile).(className) etc
    theCode.InitializeNewInstance("java.lang.String",Null)
    Dim s As String = theCode.RunMethod("getClass",Null)
    Dim l As List = inline.RunMethod("getMethods",Array(s.replace("class ","")))
    For Each item As String In l
        Log(item)
    Next
End Sub
#if java
import java.util.List;
import java.lang.reflect.Method;
import java.lang.reflect.Constructor;
import java.util.ArrayList;

public static List<String> getMethods(String cname) {
        List<String> li = new ArrayList<String>();
        Method[] methods = null;
        Class<?> c = null;
        try {
            c = Class.forName(cname);
            methods = c.getDeclaredMethods();
            System.out.println("Method count = " + methods.length);
            if (methods.length > 0 && methods != null){
                for (int a = 0 ; a < methods.length;a++){
                    li.add(methods[a].toString());
                }  
            }
        } catch (ClassNotFoundException ex) {
            System.out.println("Class not found");
        }
        return li;
    }
#end if

Hope it helps.

Thanks a lot, how do I pass to this, assuming the jarfile is me.jar and the clasname is dothat
(jarFile).(className)

 

[Daestrum]

It's like the default B4J package is b4j.example so u would pass "b4j.example.?" to the init static method.

Sorry if the jarfile.classname part was misleading, my original code reads directly from jar files, saves adding them to the project with #AdditionalJar.

You would add the jar with #AdditionalJar as usual, then simply call with "dothat" unless you have a package name, then it would be
"your.package.name.dothat"