Java access to protected methods

Hi,
I use a java toolkit, and want to access a class (Morphy) in it.
There is only one constructor function for class Morphy:
Morphy(WordNet wn).
And here is the doc of the class Morphy.
http://nlp.stanford.edu/nlp/javadoc/wn/doc/danbikel/wordnet/Morphy.html
As some methods in this class are protected, and I will call them.
Here is my code:
import danbikel.wordnet.WordNet;
import danbikel.wordnet.Morphy;
public class wn extends Morphy {
public void test(){
wn a=new wn();
a.morphWord("running","v"); // it is a protected method in Morphy
It just report an compile error: cannot find symbol: symbol : constructor Morphy().
Can anyone tell me how to fix the problem? I don't know how to add the constructor in my code.
Thanks a lot in advance.

Read [this tutorial|http://java.sun.com/docs/books/tutorial/java/IandI/super.html] from "subclass constructors" and then think about what
wn a=new wn();tries to do what it can't do.

Similar Messages

ALV - access to protected method

Hello,
I have a object from class "CL_GUI_ALV_GRID" and want to change the protected attribute "EVT_DELAYED_CHANGE_SELECTION     Constant     Protected" with the method
    CALL METHOD alv_grid->SET_DELAY_CHANGE_SELECTION
      EXPORTING
        time = lv_delay.
How can I access this protected attribute?
Thanks in advance,
Holger

This will do what you want
Trick is to define a sub class inheriting the super class where the protected attributes and methods exist in - then you can access the protected methods and attributes.
If you do this don't forget to call the SUPER CONSTRUCTOR (of the class you are inheriting from) in your constructor method. Code example shown below.
Here I want the original and modified table of an alv grid but you can adapt this code to whatever you need.
Hope it helps.
create blank screen (100) with a custom container CCONTAINER1 and the following scren logic in it
PROCESS BEFORE OUTPUT.
MODULE STATUS_0100.
PROCESS AFTER INPUT.
MODULE USER_COMMAND_0100.
now look at the code here. Note text in Bold
PROGRAM zdynfieldcat.
class zcltest definition deferred. "For field symbol reference.
Simple test of dynamic ITAB with user defined (not ddic) fields
Build dynamic fcat
Table structure obtained via new RTTI functionality
use ALV grid to display and edit.
Create a blank screen 100 with a custom container called CCONTAINER1.
James Hawthorne
Define field symbols as these can't be defined in classes
field-symbols: <dyn_table> type standard table,
               <g2> type ref to zcltest,
               <g1> type ref to cl_gui_custom_container,
               <actual_tab> type standard table,
               <outtab> type table,
               <fs1> type ANY,
               <FS2> TYPE TABLE,
               <fs3> type table,
               <fs4> type table,
               <fs5> type table.
<b>class zcltest definition inheriting from cl_gui_alv_grid.
define this as a subclass so we can access the protected attributes
of the superclass cl_gui_alv_grid</b>
public section.
    types: g4 type ref to cl_gui_custom_container.
    types: g3 type ref to cl_alv_changed_data_protocol.
    data:   i_parent type g4,
            lr_rtti_struc TYPE REF TO cl_abap_structdescr, "RTTI
    zog like line of lr_rtti_struc->components. "RTTI
    types: struc like zog.
    types: struc1 type table of struc.
    methods:
       constructor
           importing i_parent type g4,
       disp_tab
           importing p_er_data_changed type g3,
       create_dynamic_fcat
           importing zogt type struc1
           exporting it_fldcat type lvc_t_fcat.
Protected section.
   data: stab type ref to data,
        wa_it_fldcat type lvc_s_fcat,
        c_index type sy-index.
endclass.
<b>class zcltest implementation.
METHOD constructor.
    CALL METHOD super->constructor
      EXPORTING
        i_appl_events = 'X'
        i_parent      = i_parent.
      endmethod
method disp_tab.
*mt_outtab is the data table held as a protected attribute
in class cl_gui_alv_grid.
    assign me->mt_outtab->* TO <outtab>. "Original data
    assign p_er_data_changed->mp_mod_rows TO <FS1>.
    stab = p_er_data_changed->mp_mod_rows.
    assign p_er_data_changed->mt_inserted_rows to <fs3>.
    assign p_er_data_changed->mt_deleted_rows to <fs4>.
    assign p_er_data_changed->mt_mod_cells to <fs5>.
    assign stab->* TO <fs2>.
do whatever you want with <outtab>
contains data BEFORE changes each time.
Note that NEW (Changed) table has been obtained already by
call to form check_data USING P_ER_DATA_CHANGED
TYPE REF TO CL_ALV_CHANGED_DATA_PROTOCOL.
Entered data is in table defined by <fs2>
In this method you can compare original and changed data.
Easier than messing around with individual cells.
do what you want with data in <fs2> validate / update / merge etc
endmethod.</b>
method create_dynamic_fcat.
    loop at zogt into zog.
      c_index = c_index + 1.
      clear wa_it_fldcat.
      wa_it_fldcat-fieldname = zog-name .
      wa_it_fldcat-datatype = zog-type_kind.
      wa_it_fldcat-inttype = zog-type_kind.
      wa_it_fldcat-intlen = zog-length.
      wa_it_fldcat-decimals = zog-decimals.
      wa_it_fldcat-coltext = zog-name.
      wa_it_fldcat-lowercase = 'X'.
      if c_index eq 2.
        wa_it_fldcat-emphasize = 'C411'.
      endif.
      if c_index eq 3.
        wa_it_fldcat-emphasize = 'C511'.
      endif.
      append wa_it_fldcat to it_fldcat .
    endloop.
endmethod.                    "create_dynamic_fcat
endclass.                    "zcltest IMPLEMENTATION
class lcl_grid_event_receiver definition.
public section.
methods:
    handle_data_changed
         for event data_changed of zcltest
        for event data_changed of cl_gui_alv_grid
         importing er_data_changed,
    toolbar
         for event toolbar of zcltest
         importing e_object
         e_interactive,
    user_command
         for event user_command of zcltest
         importing e_ucomm.
endclass.
class lcl_grid_event_receiver implementation.
method handle_data_changed.
code whatever required after data entry.
various possibilites here as you can get back Cell(s) changed
columns or the entire updated table.
Data validation is also possible here.
    call method <g2>->disp_tab
      EXPORTING
        p_er_data_changed = er_data_changed.
endmethod.                    "handle_data_changed
method toolbar.
    data : ls_toolbar type stb_button.
    clear ls_toolbar.
    move 0 to ls_toolbar-butn_type.
    move 'EDIT' to ls_toolbar-function.
    move space to ls_toolbar-disabled.
    move 'Edit' to ls_toolbar-text.
    move icon_change_text to ls_toolbar-icon.
    move 'Click2Edit' to ls_toolbar-quickinfo.
    append ls_toolbar to e_object->mt_toolbar.
    clear ls_toolbar.
    move 0 to ls_toolbar-butn_type.
    move 'UPDA' to ls_toolbar-function.
    move space to ls_toolbar-disabled.
    move 'Update' to ls_toolbar-text.
    move icon_system_save to ls_toolbar-icon.
    move 'Click2Update' to ls_toolbar-quickinfo.
    append ls_toolbar to e_object->mt_toolbar.
    clear ls_toolbar.
    move 0 to ls_toolbar-butn_type.
    move 'EXIT' to ls_toolbar-function.
    move space to ls_toolbar-disabled.
    move 'Exit' to ls_toolbar-text.
    move icon_system_end to ls_toolbar-icon.
    move 'Click2Exit' to ls_toolbar-quickinfo.
    append ls_toolbar to e_object->mt_toolbar.
endmethod.                    "toolbar
method user_command.
    case e_ucomm .
      when 'EDIT'. "From Tool bar
        perform set_input.
        perform init_grid.
      when 'UPDA'. "From Tool bar
        perform refresh_disp.
        perform update_table.
      when 'EXIT'. "From Tool bar
        leave program.
    endcase.
endmethod.                    "user_command
endclass.                    "lcl_grid_event_receiver IMPLEMENTATION
program data
include <icon>.
define any old internal structure NOT in DDIC
types: begin of s_elements,
anyfield1(20) type c,
anyfield2(20) type c,
anyfield3(20) type c,
anyfield4(20) type c,
anyfield5(11) type n,
end of s_elements.
data: wa_element type s_elements,
wa_data type s_elements.
Note new RTTI functionality allows field detail retrieval
at runtime for dynamic tables.
data:
        grid1 type ref to zcltest,
        grid_handler type ref to lcl_grid_event_receiver,
        c_dec2 type s_elements-anyfield5,
        wa_it_fldcat type lvc_s_fcat,
        it_fldcat type lvc_t_fcat,
        lr_rtti_struc TYPE REF TO cl_abap_structdescr, "RTTI
        lt_comp TYPE cl_abap_structdescr=>component_table,"RTTI
        ls_comp LIKE LINE OF lt_comp, "RTTI
        zog like line of lr_rtti_struc->components, "RTTI
        struct_grid_lset type lvc_s_layo,
        l_valid type c,
        new_table type ref to data.
        types: struc like zog.
data: zogt type table of struc,
        grid_container1 type ref to cl_gui_custom_container,
        g_event_receiver type ref to lcl_grid_event_receiver,
        ok_code like sy-ucomm,
        i4 type int4.
start-of-selection.
call screen 100.
module status_0100 output.
if grid_container1 is initial.
    create object grid_container1
    exporting
    container_name = 'CCONTAINER1'.
    assign grid_container1 to <g1>.
    create object grid1
     exporting i_parent = grid_container1.
we need reference to this instance so we can use
Methods etc of zcltest class and alv (superclass)
in our event receiver class.
     assign grid1 to <g2>.
    create object grid_handler.
    set handler:
    grid_handler->user_command for grid1,
    grid_handler->toolbar for grid1,
    grid_handler->handle_data_changed for grid1.
Get the Internal table structure
    lr_rtti_struc ?= cl_abap_structdescr=>describe_by_data( wa_data ).
Build field catalog just use basic data here
colour specific columns as well
    zogt[] = lr_rtti_struc->components.
      call method grid1->create_dynamic_fcat
      EXPORTING
        zogt      = zogt
      IMPORTING
        it_fldcat = it_fldcat.
Create dynamic internal table and assign to field symbol.
Use dynamic field catalog just built.
call method cl_alv_table_create=>create_dynamic_table
    EXPORTING
      it_fieldcatalog = it_fldcat
    IMPORTING
      ep_table        = new_table.
assign new_table->* to <dyn_table>.
    perform populate_dynamic_itab.
    perform init_grid.
    perform register_enter_event.
set off ready for input initially
    i4 = 0.
    call method grid1->set_ready_for_input
      EXPORTING
        i_ready_for_input = i4.
endif.
endmodule.                    "status_0100 OUTPUT
module user_command_0100 input.
*PAI not needed in OO ALV anymore as User Commands are handled as events
*in method user_command.
*we can also get control if the Data entered and the ENTER is pressed by
*raising an event.
Control then returns to method handle_data_changed.
endmodule.                    "user_command_0100 INPUT
form populate_dynamic_itab.
load up a line of the dynamic table
c_dec2 = c_dec2 + 11.
wa_element-anyfield1 = 'Tabbies'.
wa_element-anyfield2 = 'ger.shepards'.
wa_element-anyfield3 = 'White mice'.
wa_element-anyfield4 = 'Any old text'.
wa_element-anyfield5 = c_dec2.
append wa_element to <dyn_table>.
endform.                    "populate_dynamic_itab
form exit_program.
call method grid_container1->free.
call method cl_gui_cfw=>flush.
leave program.
endform.                    "exit_program
form refresh_disp.
call method grid1->refresh_table_display.
endform.                    "refresh_disp
form update_table.
The dynamic table here is the changed table read from the grid
after user has changed it
Data can be saved to DB or whatever.
loop at <dyn_table> into wa_element.
do what you want with the data here
endloop.
switch off edit mode again for next function
i4 = 0.
call method grid1->set_ready_for_input
    EXPORTING
      i_ready_for_input = i4.
endform.                    "update_table
form set_input.
i4 = 1.
call method grid1->set_ready_for_input
    EXPORTING
      i_ready_for_input = i4.
endform.                    "set_input
form switch_input.
if i4 = 1.
    i4 = 0.
else.
    i4 = 1.
endif.
call method grid1->set_ready_for_input
    EXPORTING
      i_ready_for_input = i4.
endform.                    "switch_input
form init_grid.
Enabling the grid to edit mode,
struct_grid_lset-edit = 'X'. "To enable editing in ALV
struct_grid_lset-grid_title = 'Jimbos Test'.
   call method grid1->set_table_for_first_display
    EXPORTING
      is_layout       = struct_grid_lset
    CHANGING
      it_outtab       = <dyn_table>
      it_fieldcatalog = it_fldcat.
endform.                    "init_grid
form register_enter_event.
call method grid1->register_edit_event
    EXPORTING
      i_event_id = cl_gui_alv_grid=>mc_evt_enter.
Instantiate the event or it won't work.
create object g_event_receiver.
set handler g_event_receiver->handle_data_changed for grid1.
endform.                    "register_enter_event

Access to protected method is ot allowed

Hi,
there is class with a protected method. I get the message
"Access to protected method is ot allowed"
How must such methods be called if they are protected ?
Regards
sas

Erdem, please try to post in the correct forum. ABAP Objects questions belong in this forum, not general.
Second, Amit Khare is correct. The concept of Public/Protected/Private methods and attributes is not limited to ABAP Objects. It is a common concept to most object oriented programming languages. But if your read the ABAP Help on the appropriate keywords, then it is explained very clearly.
matt

ECATT: How to access a protected method of a class with eCATT?

Hi,
These is a class with a protected method. now i am willing to automate the scenario with eCATT. Since the method is Protected i am unable to use createobj and use callmethod. Could anyone suggest me a work around for this ?
Regards
Amit
Edited by: Amit Kumar on Jan 10, 2012 9:53 AM

Hello Anil,
You can write ABAP Code to do that inside eCATT Command.
ABAP.
ENDABAP.
Limitation of doing that is you can only use local variable inside ABAP.... ENDABAP. bracket.
Regards,
Bhavesh

Innerclass access of extended protected methods

I have a subclass X() which extends class Y() and has an anonymous innerclass. The innerclass extends classs z() and accesses a protected method of the extended class y(). This works fine in jdk1.3, but causes a java.lang.NoSuchMethodError in jdk1.4...
Any ideas on why it works in jdk1.3 but not in jdk1.4?
Thanks,
Bruce

Sorry, you were correct... I was going between jdk1.4
and jdk1.3 and messed up. Let me restate the problem:
I have a class CreateVLANGroup() which extends class ProvisionPanel().
Class CreateVLANGroup() creates an instance of WaitMessageHandler(). WaitMessageHandler() has a method setExecutionCommand() which takes as an argument "ExecutionCommandInterface object". CreateVLANGroup() uses an anonymous innerclass to create this argument for the call to setExecutionCommandInterface(). It is the call "CreateVLANGroup.this.displayModelData()" from within the innerclass that causes the jdk1.4 error.
See the snippet of code from CreateVLANGroup() below.
     public CreateVLANGroup(PF3000View view, DMXEthernetCircuitPack model)
          super(view, model);
          ... initialization code here
WaitMessageHandler handler = new WaitMessageHandler(this,
"Retrieving data for this Ethernet Circuit Pack, please wait...");
handler.setExecutionCommand(new ExecutionCommandInterface()
public void execute(Object target) {
if (systemProperties.isTrue("ExpandedEthernetSupported")) {
virtualIDs = m_dmxPortCircuitPack.getVRTSWFabric().getAllVRTSWIds().toArray();
if (getVirtualSwitches() != null &&
getVirtualSwitches().length != 0)
CreateVLANGroup.this.displayModelData();
else
return;
} else {
displayModelData();
handler.execute(new Object());
The actual error that I'm getting at runtime is:
java.lang.NoSuchMethodError: com.lucent.cit.gui.sysview.core.common.ProvisionPanel.access$301(Lcom/lucent/cit/gui/sysview/product/dialogs/provision/CreateVLANGroup;)V
at com.lucent.cit.gui.sysview.product.dialogs.provision.CreateVLANGroup$1.execute(CreateVLANGroup.java:58)
at com.lucent.cit.gui.util.waiting.WaitMessageHandler$WaitMessageHandlerThread.run(WaitMessageHandler.java:595)

How to Access Protected Method of a Class

Hi,
I need to access a Protected method (ADOPT_LAYOUT) of class CL_REIS_VIEW_DEFAULT.
If i try to call that method by using class Instance it is giving error as no access to protected class. Is there any other way to access it..

Hi,
You can create a sub-class of this class CL_REIS_VIEW_DEFAULT, add a new method which is in public section and call the method ADOPT_LAYOUT of the super-class in the new method. Now you can create an instance of the sub-class and call the new sub-class method.
REPORT ZCD_TEST.
class sub_class definition inheriting from CL_REIS_VIEW_DEFAULT.
public section.
methods: meth1 changing cs_layout type LVC_S_LAYO.
endclass.
class sub_class implementation.
method meth1.
call method ADOPT_LAYOUT changing CS_LAYOUT = cs_layout.
endmethod.
endclass.
data: cref type ref to sub_class.
data: v_layout type LVC_S_LAYO.
start-of-selection.
create object cref.
call method cref->meth1 changing cs_layout = v_layout.

Protected methods, what did i do wrong?

Hi there, I'm trying to understand why I cant access a Protected Method from a library that I'm trying to use..
Some guidance would be great:
public class Registration {
//Create new instance of ConnectionBean
ConnectionBean conBean = new ConnectionBean();
public Registration() {
public void regUser() {
String server = JOptionPane.showInputDialog( "Enter Server address" );
InetAddress inetaddress;
try {
conBean.connect( inetaddress = InetAddress.getByName( server ));
catch( UnknownHostException unknownhostexception ) {
Object aobj[] = {
"Cancel", "OK"
int i = JOptionPane.showOptionDialog(null, "Retry Server?", server +
": Not Responding", -1, 2, null, aobj, aobj[1]);
if( i == 1 )
regUser();
System.out.println( "Cannot resolve " + server + ":" + unknownhostexception.toString ());
return;
catch( IOException ioexception ) {
Object aobj1[] = {
"Cancel", "OK"
int j = JOptionPane.showOptionDialog( null, "Cannot Connect to:",
server,-1, 2, null, aobj1, aobj1[1] );
if( j == 1 )
regUser();
System.out.println( "Cannot connect " + server);
return;
System.out.println( "Registering User" );
registrationProcess();
public void registrationProcess () {
InfoQueryBuilder iqb = new InfoQueryBuilder();
InfoQuery iq;
IQRegisterBuilder iqRegb = new IQRegisterBuilder();
IQRegister iqReg = new IQRegister( iqRegb );
try {
//Need to getXMLNS packet method getXMLNS() is protected
iqReg.getXMLNS();
catch ( InstantiationException e ) {
System.out.println( "Error in building Registration packet" );
String username = JOptionPane.showInputDialog( "Enter: Username" );
String password = JOptionPane.showInputDialog( "Enter: Password" );
The error as would be expected:
Registration.java:96: getXMLNS() has protected access in org.jabber.jabberbeans.Extension.IQRegister
iqReg.getXMLNS();
^
1 error
Appreciate the help!! :)

I tried to extend the class to make it a subclass of IQRegister (which holds the protected method) but I'm getting this error:
Reg.java:19: cannot resolve symbol
symbol : constructor IQRegister ()
location: class org.jabber.jabberbeans.Extension.IQRegister
public class Reg extends IQRegister {
^
1 error
Any ideas?
thanks

Problems on protected methods

Hi!
Im rhani, im new to java programming....i was trying to run this code from a book (below) :
import java.awt.*;
public class FrameExample extends Frame {
public static void main(String args[]){
FrameExample win = new FrameExample();
public FrameExample() {
super("FrameExample");
pack();
resize(400,400);
show();
public void paint(Graphics g) {
g.drawString("A Basic Window Program",100,100);
public boolean handleEvent(Event event) {
if(event.id==Event.WINDOW_DESTROY){
System.exit(0);
return true;
}else return false;
(Im using jdk1.3.1_12)
ahmm now it says that the method handleEvent is deprecated. Now then I tried to replaced it with :
protected void processEvent (AWTEvent e) {
if (e.getID == Event.WINDOW_DESTROY) {
System.exit(0);
no errors but i know my "if " condition is wrong....when i try to use e.id == WINDOW_DESTROY it says that im trying to access a protected method on that. Im just having difficulty in what really does a protected method does..or its limitations....and how would I be able to handle that the user is trying to close the frame/window. I would really do appreciate your help on this....I hope I had explained it clearly, ahm im not good in english...ahmm thank you very much!!!

thank you very much sir for the fast reply...ahm i dont know if Im using the right method...ahmm its just that the documentation here http://java.sun.com/j2se/1.3/docs/api/ says that it inherits a method from Class Component, then it says that I should use processEvent, ahm the processEvent there is declared protected void processEvent ( AWTEvent e). Then on e.getID() ahm it says that it returns an int value I just thought that its value is like WINDOW_DESTROY or something...thank you very much again sir for the help...

How to get protected method ?

I thought i can get protected method of my class when calling a Class.getMethod(String, Class []) in another class which inside the same package. However, it seem that i can't do that because it throw me a NoSuchMethodException when the method was protected. I thought all classes in same package can access the protected methods or fields of each other ??? Why ?
So, how i'm able to get the protected method in runtime ? (Hopefully no need to do anything with the SecurityManager)

It is working
Pls try the following program ...
public class p1 {
public static void main(String as[]) {
p2 ps2 = new p2();
ps2.abc();
class p2 {
protected void abc() {
System.out.println("Hello");
regards,
namanc

How to access a proctected method of a class

Hi All,
I have the below code where in the idents_get is a protected method of the class.so when i activate it is throwing an error, method is unkown or protected or private.
data: gv_class TYPE REF TO /tdag/cpcl_decl_sub_view_ctrl.
   create object gv_class.
    CALL METHOD gv_class->idents_get
      EXPORTING
        i_estcat       = gc_estcat6
        i_pos_wanted   = 1
      IMPORTING
        et_idents      = lt_idents
      changing
        xt_recns       = li_recn
      EXCEPTIONS
        read_failed    = 1
        others         = 2.
i know protected methods can be accessed in derived class.
I'm new to ABAP oops concepts please give me some pointers to access a protected method.
or any sample code to access protected method.
Thanks in advance,
Srilakshmi.

Hello Srilakshmi
You can access protected methods WITHIN an instance of the class or WITHIN an instance of a sub-class.
However, in your case you are calling the method from the report and, therefore, the class must be PUBLIC.
Regards
Uwe

OOABAP-How to access the protected methos from a class

How to access the protected methos from a class..There is a built in class..For tht class i have created a object..
Built in class name : CL_GUI_TEXTEDIT
method : LIMIT_TEXT.
How to access this..help me with code

hi,
If inheritance is used properly, it provides a significantly better structure, as common components only
need to be stored once centrally (in the superclass) and are then automatically available to subclasses.
Subclasses also profit immediately from changes (although the changes can also render them invalid!).
Inheritance provides very strong links between the superclass and the subclass. The subclass must
possess detailed knowledge of the implementation of the superclass, particularly for redefinition, but also in
order to use inherited components.
Even if, technically, the superclass does not know its subclasses, the
subclass often makes additional requirements of the superclass, for example, because a subclass needs
certain protected components or because implementation details in the superclass need to be changed in
the subclass in order to redefine methods.
The basic reason is that the developer of a (super)class cannot
normally predict all the requirements that subclasses will later need to make of the superclass.
Inheritance provides an extension of the visibility concept: there are protected components. The visibility of
these components lies between that of the public components (visible to all users, all subclasses, and the class itself), and private (visible only to the class itself). Protected components are visible to and can be used by all subclasses and the class itself.
Subclasses cannot access the private components particularly attributes) of the superclass. Private
components are genuinely private. This is particularly important if a (super)class needs to make local
enhancements to handle errors: it can use private components to do this without knowing or invalidating
subclasses.
Create your class inse24 and inherit this CL_GUI_TEXTEDIT
class in yours. You can then access the protected methods.
Hope this is helpful, <REMOVED BY MODERATOR>
Edited by: Runal Singh on Feb 8, 2008 1:08 PM
Edited by: Alvaro Tejada Galindo on Feb 19, 2008 2:19 PM

Protected methods not so protected

Hi,
I thought that a protected method could be called only by the methods of
the same class or the methods of a descendant class.
So I have been a bit surprised when I constated that a class
of a given package can access the protected method of all the classes in the same package !! I thought that this behaviour was reserved to the method with no access modifiers.
Example :
package mypackage;
* A first class with a protected method
public class HasProtectedMethod {
protected void iAmProtected() {
System.out.print("I am protected");
* Another class in the same package trying to access the protected
* method of the first class
package com.akazi.flowmind.modeling.gui;
import com.akazi.flowmind.modeling.gui.dialog.HasProtectedMethod;
public class Test {
static public void main(String[] args) {
new Test().callProtected();
public void callProtected() {
HasProtectedMethod method = new HasProtectedMethod();
method.iAmProtected();
This code is perfectly compiling and running under JBuilder6 and I wonder if this is correct...

This is very odd to me.
In my application, I've got a bunch of classes with subclasses, and I want the protected methods to be accessible only to the subclasses, not to the rest of the stuff in the package.
Is there no way to keep these protected methods and member variables safe, other than to make a package for each superclass? That means that the client application I am writing will baloon from one package to around 46. Ugh.
So should I just give up on data hiding for now? Did I design this thing all wrong? Maybe we're supposed to use lots and lots of packages. What do people do?
--- Eric

Why Java doesn't allow to reduce the accessibility of a method du

Why Java compiler does not allow to reduce the accessibility of a method during inheritance?
( Eg; If the base class has a public method and if that method is overridden in child class but
with defuault access, it gives compile error)
Supposed answer:
Because in the runtime, it cannot check the access modifier.
Suppose A is the base class. It has a method fun() as public.
B is the derived class of A.
Suppose in some other class (say C) there is a method myFun() which takes A as parameter and
calls the fun() method of A. So that method can take B
also as parameter (As it is derived from A).
So if the fun() method's accessibility is reduced in B, whether "that can
be called in C or not" is not known. that is why compiler does not
allow the reduce the accessibility of a method during inheritance.
Member variables do not have this problem as they can be checked at
compile time.
Is this explanation correct?

You can give private access, sort of... you could fake it, if the goal is to prevent someone from doing what the method does. Of course, they could (as long as A isn't abstract) create their own A and do whatever they want.
class A {
   public void doThis() {
class B extends A {
   public void doThis() {
      // explicitly do nothing
}But I think generally, this shouldn't be a problem. I'm not sure if it's something that is common for creating an API to subclass another class to hide the superclass's methods. Usually you are adding functionality to a subclass that is for more specific things then the superclass supports. I mention creating an API because if it's just for some application class, then you are writing it, so use or not use the methods as you want. It's APIs for library type classes that other people would use, and if you are extending the library, and really need people not to call methods for some reason, document it. Maybe a good place for an assertion?

How to use protected method in jsp code

Could anyone tell me how to use protected method in jsp code ...
I declare a Calendar class , and I want to use the isTimeSet method ,
But if I write the code as follows ..
========================================================
<%
Calendar create_date = Calendar.getInstance();
if (create_date.isTimeSet) System.out.println("true");
%>
============================================================
when I run this jsp , it appears the error wirtten "isTimeSet has protected access in java.util.Calendar"

The only way to access a protected variable is to subclass.
MyCalendar extends Calendar
but I doubt you need to do this. If you only want to tell if a Calendar object has a time associated with it, try using
cal.isSet( Calendar.HOUR );

Not sure how to use protected method in arraylisy

Hi,
Im wondering how to use the removeRange method in java arraylist, its a protected method which returns void.
http://java.sun.com/j2se/1.3/docs/api/java/util/ArrayList.html#removeRange(int,%20int)
So if my class extends Arraylist i should be able to call the method but the compiler states that it still has protected access in arraylist. Does this mean im still overriding the method in arraylist ? A little explanation of whats happeneing would be appreciated as much as an answer
thanks

In this codefinal class myClass extends java.util.ArrayList {
    private ArrayList array = new ArrayList();
    public myClass(ArrayList ary){
        for(int i=0;i<7;i++) {
            array.add(ary.get(i));
        ary.removeRange(0,7)
}You are defining a class called myClass which extends ArrayList.
You have a member variable called array which is an ArrayList
You have a constructor which takes a parameter called ary which is an ArrayList
Since ary is an ArrayList, you cannot call it's removeRange() method unless myClass is in the java.util package. Do not put your class in the java.util package.
It seems like what you want to do is to move the items in one ArrayList to another ArrayList rather than copying them. I wrote a program to do this. Here it isimport java.util.*;
public class Test3 {
public static void main(String[] args) {
    MyClass myClass = new MyClass();
    for (int i=0; i<5; i++) myClass.add("Item-"+i);
    System.out.println("------ myClass loaded -------");
    for (int i=0; i<myClass.size(); i++) System.out.println(myClass.get(i));
    MyClass newClass = new MyClass(myClass);
    System.out.println("------ newClass created -------");
    for (int i=0; i<newClass.size(); i++) System.out.println(newClass.get(i));
    System.out.println("------ myClass now contains -------");
    for (int i=0; i<myClass.size(); i++) System.out.println(myClass.get(i));
class MyClass extends java.util.ArrayList {
    public MyClass() {}
    public MyClass(MyClass ary){
        for(int i=0;i<ary.size();i++) add(ary.get(i));
        ary.removeRange(0,ary.size());
}You should notice now that I don't create an ArrayList anywhere. Everything is a MyClass. By the way, class names are normally capitalized, variable names are not. Hence this line
MyClass myClass = new MyClass();
In the code above I create an empty MyClass and then populate it with 5 items and then print that list. Then I create a new MyClass using the constructor which takes a MyClass parameter. This copies the items from the parameter list into the newly created MyClass (which is an ArrayList) and then removes the items from the MyClass passed as a parameter. Back in the main() method, I then print the contents of the two MyClass objects.
One thing which may be a little confusing is this line.
for(int i=0;i<ary.size();i++) add(ary.get(i));
the add() call doesn't refer to anything. What it really refers to is the newly created MyClass object which this constructor is building. This newly created object is the 'this' object. So the line above could be rewritten as
for(int i=0;i<ary.size();i++) this.add(ary.get(i));
Hopefully this helps a little. The problems you seem to be having are associated with object oriented concepts. You might try reading this
http://sepwww.stanford.edu/sep/josman/oop/oop1.htm

Java access to protected methods

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