Purpose

Here is a Java Bean that allows to manage an "auto completion" Swing JComboBox.







The Java code

     CBAutoCompletion.java     ComboBoxCompletion.java



The implementation class of the Bean Item

     oracle.forms.fd.ComboBoxCompletion

The methods you can set



Init the ComboBox values

-- Single value list --
Get_Custom_Property('BLOCK.ITEM',1,'INIT','value[,value[,...]]');

e.g.:
-- initialise the ComboBox values --
Set_Custom_Property('BL.BEAN',1,'INIT','Ester,Jordi,Jordina,Jorge,Sergi');    

-- Twin value list (code+value) --
Get_Custom_Property('BLOCK.ITEM',1,'INIT_TWIN','code,value[,code,value[,...]]');
code(stored value) is provided, then after value (displayed)

e.g.:
-- initialise the ComboBox values --
Set_Custom_Property('BL.BEAN',1,'INIT_TWIN','v1,Ester,v2,Jordi,v3,Jordina,v4,Jorge,v5,Sergi');

This method must be the first called.

If you need to incorporate NULL values in the list, use the equivalent INIT_NULL and INIT_TWIN_NULL methods.

To set the focus on the NULL value, use the SELECT_INDEX,'1' or SELECT_CODE,'' methods.

If the amount of data to transfer is greater than 4000 bytes, replace the INIT[_NULL] or INIT_TWIN[_NULL] methods by the equivalent ADD[_NULL] of ADD_TWIN[_NULL]:

  Set_Custom_Property('BL.BEAN',1,'CLEAR','');
  Set_Custom_Property('BL.BEAN',1,'ADD_TWIN','v1,Ester,v2,Jordi,v3,Jordina');
  Set_Custom_Property('BL.BEAN',1,'ADD_TWIN','v4,Jorge,v5,Sergi,v6,Theodor');
  Set_Custom_Property('BL.BEAN',1,'ADD_TWIN','......');
  Set_Custom_Property('BL.BEAN',1,'ADD_TWIN','[END_DATA]');

In this case, the last call to ADD_XXX methods must contains the [END_DATA] string.

Set the Font

Get_Custom_Property('BLOCK.ITEM',1,'SET_FONT','font_name[,font_weight[,font_size]]);

font_weight could be one of the following:

P  : Plain
B  : Bold
I : Italic
BI : Bold+Italic

e.g.:
-- set the font --
Set_Custom_Property('BL.BEAN',1,'SET_FONT','Arial,B,12'); 

Enable/disable the combobox

Get_Custom_Property('BLOCK.ITEM',1,'SET_ENABLED','true | false');

e.g.:
-- disable the ComboBox --
Set_Custom_Property('BL.BEAN',1,'SET_ENABLED,'false');   

Show/hide the ComboBox values

Get_Custom_Property('BLOCK.ITEM',1,'SET_VISIBLE','true | false');

e.g.:
-- hide the ComboBox --
Set_Custom_Property('BL.BEAN',1,'SET_VISIBLE,'false');   

Set the starting index (by position)

Get_Custom_Property('BLOCK.ITEM',1,'SELECT_INDEX','index_num');

e.g.:
-- set focus on the 3rd option --
Set_Custom_Property('BL.BEAN',1,'SELECT_INDEX','3');   

Set the starting index (by code)

Get_Custom_Property('BLOCK.ITEM',1,'SELECT_CODE','code');

e.g.:
-- set focus on the 3rd option --
Set_Custom_Property('BL.BEAN',1,'SELECT_CODE','v2');   

Set the starting index (by value) twin value list only

Get_Custom_Property('BLOCK.ITEM',1,'SELECT_VALUE','value);

e.g.:
-- set focus on the 3rd option --
Set_Custom_Property('BL.BEAN',1,'SELECT_VALUE','Jordi');   

The event raised by the bean

SELECTION_CHANGED

Each time the end user change the current value of the combobox, a message is send to Forms.

You can get this message in the When-Custom-Item-Event trigger of the Bean Item:
The index number is read from the SELECTION_INDEX list parameter
The code is read from the SELECTION_CODE list parameter
The value is read from the SELECTION_VALUE list parameter

DECLARE
    eventName varchar2(30) := :system.custom_item_event;
    eventValues ParamList;
    eventValueType number;
    LC$Index  varchar2(10);
    LC$Code  varchar2(1000);
    LC$Value  varchar2(1000);
BEGIN
   IF (eventName='SELECTION_CHANGED') THEN
      eventValues := get_parameter_list(:system.custom_item_event_parameters);
      get_parameter_attr(eventValues,'SELECTION_INDEX',eventValueType, LC$Index);
      get_parameter_attr(eventValues,'SELECTION_Code',eventValueType, LC$Code);
      get_parameter_attr(eventValues,'SELECTION_VALUE',eventValueType, LC$Value);
    
      -- display the current selction --
      :BL.SELECT := '[' || LC$Index || '] (' || LC$Code || ') ' || LC$Value ;

   END IF;
END;

The sample dialog


     . Download the CBAutoCompletion.zip file
     . Unzip the file
     . copy the ComboBoxCompletion.jar file in the <ORACLE_HOME>/forms/java directory
     . Edit your /forms/server/formsweb.cfg file to add the ComboBoxCompletion.jar .
     . Open the CBAUTOCOMPLETION.fmb module (Oracle Forms 9.0.2)
     . Compile all and run the module

     The JAR file has to be signed.

Purpose

Here is a Java Bean that allows sending back to the Forms application each key pressed in any Text Item.







The Java code

     keypressed.java



The implementation class of the Bean Item

     oracle.forms.fd.KeyPressed


The methods you can call




Initialize the bean

Set_Custom_Property('BLOCK.ITEM',1,'INIT','');

This method must be called in the When-New-Form-Instance. It is used to search for every Text Items in the Forms to attach to them a key listener.

e.g.:
-- Init the bean --
Set_Custom_Property( 'BL.BEAN', 1, 'INIT', '' ) ; 

The event fired by the JavaBean


KEY_PRESSED


It is constituted by 3 parameters to get the key code, the key char and the key modifier.

To know what text item has just fired the event, ask the :SYSTEM.CURSOR_ITEM variable.

When-Custom-Item-Event:

DECLARE
  
    eventName varchar2(30) := :system.custom_item_event;
    eventValues ParamList;
    eventValueType number;
    LC$Code   varchar2(25); -- code
    LC$Char   varchar2(25); -- char
    LC$Modif  varchar2(25); -- modifier

  
BEGIN
  
   IF (eventName='KEY_PRESSED') THEN
      eventValues := get_parameter_list(:system.custom_item_event_parameters);
      get_parameter_attr(eventValues,'KEY_CODE',eventValueType, LC$Code);
      get_parameter_attr(eventValues,'KEY_CHAR',eventValueType, LC$Char);
      get_parameter_attr(eventValues,'KEY_MODIFIER',eventValueType,  LC$Modif);
     
      :BL.RESULT := :System.cursor_item || ' Key pressed:'|| LC$Code || ' (' || LC$Char||') '||' modif:'||LC$Modif ;
      Synchronize ;

   END IF; 
  
END;





The sample dialog


     . Download the keypressed.zip file
     . Unzip the file
     . copy the keypressed.jar file in the <ORACLE_HOME>/forms/java directory
     . Edit your /forms/server/formsweb.cfg file to add the keypressed.jar .
     . Open the KEYPRESSED.fmb module (Oracle Forms 9.0.2)
     . Compile all and run the module

Purpose

Here is a Java Bean that allows reading, displaying with scaling and writing images.

It allows scaling images to fit the target item size, and includes a FileChooser with image preview dialog.

In its third version, it does not need any JDBC connexion to handle images from/to the database.

It uses the JRE 1.4 javax.imageio.ImageIO package, so it needs, at least the Sun Java plugin 1.4.
It won't run against JInitiator.






The Java code

     HandleImage.java      GetImageFileName.java



The implementation class of the Bean Item

     oracle.forms.fd.HandleImage


The methods you can call




Read an image from a file

Set_Custom_Property('BLOCK.ITEM',1,'READIMGFILE','the_complete_filename');

e.g.:
-- read image from the file system --
Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGFILE', 'D:/image.jpg' ) ; 

-- read image from the JAR file --
Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGFILE', '/image.jpg' ) ;

-- read image from the Internet --
Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGFILE', 'http://the_url/image.jpg' ) ;

Read an image from the database table

The reading process is composed by three steps:

1. Select the Blob table's column
2. Read the image chunks and send them to the Java Bean
3. End the sending process

1. Select the Blob table's column:

Pkg_Read_Blob_Image.Select_Blob(LC$Clause); (*)

LC$Clause is a string that must contain the Select order to fetch the corresponding single row:

 LC$Clause := 'Select PHOTO_JAVA From PHOTOS Where IDENTIFIANT = 10'  ;
 -- Select the Blob column --
 If Pkg_Read_Blob_Image.Select_Blob(LC$Clause) Then
    ...

2. Read the image chunks from the database then send them to the Java Bean:

Pkg_Read_Blob_Image.Get_B64_Chunk() (*)

     -- Get the image chunks from the database --
     LC$Image := Pkg_Read_Blob_Image.Get_B64_Chunk ;
     If LC$Image Is Not Null Then
       -- Send the chunks to the Java Bean --
       Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGBASE', LC$Image ) ;

3. End the sending process:

     Else
       -- End the sending process --
       Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGBASE', '[END_IMAGE]' ) ;

(*) the PKG_READ_BLOB_IMAGE database's package is provided with the zip file.

e.g.:

PROCEDURE Read_Image IS
  LB$Ok      boolean ;
  LC$Image   Varchar2(32767) ;
  LC$Clause  Varchar2(4000) ;
BEGIN
 
 --
 -- Read an image from the database
 --
 LC$Clause := 'Select PHOTO_JAVA From PHOTOS Where IDENTIFIANT = ' || :PHOTOS.IDENTIFIANT ;
 -- Select the Blob column --
 If Pkg_Read_Blob_Image.Select_Blob(LC$Clause) Then
   Loop
     -- Get the image chunks from the database --
     LC$Image := Pkg_Read_Blob_Image.Get_B64_Chunk ;
     If LC$Image Is Not Null Then
       -- Send the chunks to the Java Bean --
       Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGBASE', LC$Image ) ;
     Else
       -- End the sending process --
       Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGBASE', '[END_IMAGE]' ) ;
       Exit ;
     End if ; 
   End loop ;
 End if ; 
  
END;


Put this method into the When-New-Record-Instance block-level trigger


Write an image to the database table

The writing process is also composed by three steps:

1. Initialize the transfer
2. Read the image chunks from the Java Bean and send them to the database
3. Update the Blob column with the new content

1. Initialize the transfer:

Pkg_Read_Blob_Image.Init_Transfer() (*)

This will empty the current Blob column:

 Pkg_Read_Blob_Image.Init_Transfer ;

2. Read the image chunks from the Java Bean and send them to the database:

Get_Custom_Property('BLZ.BEAN',1,'GETIMAGE');

Pkg_Read_Blob_Image.Set_B64_Chunk(LC$Req) (*)

    Loop
      -- Get the image chunk from the Java Bean --
      LC$Req := Get_Custom_Property('BLZ.BEAN',1,'GETIMAGE');
      Exit When LC$Req is null ;
      ...   
      -- Send the image chunks to the Database --
      Pkg_Read_Blob_Image.Set_B64_Chunk(LC$Req);
    End loop;

3. Update the Blob column with the new content:

     LC$Res := Pkg_Read_Blob_Image.Save_Blob('PHOTOS','PHOTO_JAVA','IDENTIFIANT=' || :PHOTOS.IDENTIFIANT );

The Save_Blob() function takes the table name, the blob column name and the Where clause arguments.

(*) the PKG_READ_BLOB_IMAGE database's package is provided with the zip file.

Put this method into the Post-Insert and Post-Update block-level trigger

e.g.:

PROCEDURE Save_Image IS
    LC$Req  Varchar2(32000);
    LN$Cpt  Pls_integer := 0 ;
    LC$Res  Varchar2(2000) ;
BEGIN
    --
    -- Save the image to the database
    --
    Loop
      -- Get the image chunk from the Java Bean --
      LC$Req := Get_Custom_Property('BLZ.BEAN',1,'GETIMAGE');
      Exit When LC$Req is null ;
      LN$Cpt := LN$Cpt + 1 ;
      If Ln$Cpt = 1 Then
         Pkg_Read_Blob_Image.Init_Transfer ;
      End if ;  
      -- Send the image chunks to the Database --
      Pkg_Read_Blob_Image.Set_B64_Chunk(LC$Req);
    End loop;
    If LN$Cpt > 0 Then
      -- Update the Blob column with the new content --
      LC$Res := Pkg_Read_Blob_Image.Save_Blob('PHOTOS','PHOTO_JAVA','IDENTIFIANT=' || :PHOTOS.IDENTIFIANT );
    End if ;
    Clear_Message ;
    Message('Result:'|| LC$Res, no_acknowledge);
END;


Put this method into the Post-Insert and Post-Update block-level triggers


Clear the image

Set_Custom_Property( 'BL.BEAN', 1, 'CLEAR' , '' ) ;

This function has to be called in a When-New-Record-Instance trigger if the record does not exist:

When-New-Record-Instance trigger:
If :PHOTOS.IDENTIFIANT is not null Then
   Read_Image ;
Else
   Set_Custom_Property( 'BLZ.BEAN', 1, 'CLEAR', '' ) ;
End if ;
:BLZ.IMG_SIZE := Get_Custom_Property( 'BLZ.BEAN', 1, 'GETSIZE' ) ;


Set the display image scalling

This function concerns only the image displayed. The image stored with the WRITEIMGBASE method will be the initial image.

Set_Custom_Property( 'BL.BEAN', 1, 'SCALE_IMAGE ','Width=x,Height= y' ) ;

Both Width and Height parameters must be transmitted

x and y can take the following values:

Any value greater then 0 that express an absolute size in pixels
the special value: FIT that extends the image to fit the exact size of the image panel' size
-1 that to keep the corresponding aspect ratio
0 that indicates no scale at all

Examples:

-- Scale the image to fit horizontally and vertically the image item --
Set_Custom_Property('BLZ.BEAN',1,'SCALE_IMAGE', 'Width=FIT,Height=FIT' ) ;

-- Scale the image to 200x100 pixels --
Set_Custom_Property('BLZ.BEAN',1,'SCALE_IMAGE', 'Width=200,Height=100' ) ;

-- Scale the image to 200 horizontal pixels and keep vertical aspect ratio --
Set_Custom_Property('BLZ.BEAN',1,'SCALE_IMAGE', 'Width=200,Height=-1' ) ;




Display/hide the image panel' scrollbars

Set_Custom_Property('BLOCK.ITEM',1,'SETSCROLL','true|false');

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'SETSCROLL', 'true' ) ; 





Set the item border

Set_Custom_Property('BLOCK.ITEM',1,'SETBORDER','thick[,color]');

e.g.:

-- set a null border --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SETBORDER', '0' ) ; 

-- set a 4 pixel red border --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SETBORDER', '4,r255g0b0' ) ; 



Set the JFileChooser title and starting directory

Set_Custom_Property('BLOCK.ITEM',1,'SET_FILECHOOSER_TITLE','title[,directory]');

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_TITLE', 'Select a file,D:/' ) ; 

the directory argument is not mandatory



Set the JFileChooser Look and Feel

Set_Custom_Property('BLOCK.ITEM',1,'SET_FILECHOOSER_LAF','SYSTEM|other_value');

e.g.:
-- use the current O.S. L&F --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_LAF ', 'SYSTEM' ) ; 

-- use the Metal L&F --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_LAF ', 'JAVA' ) ; 


Set the log mode to output the Bean messages

Set_Custom_Property( 'BL.BEAN', 1, 'SETLOG' , 'true|false' ) ;

In the sample dialog provided, here is the code used in the When-New-Form-Instance trigger:

PROCEDURE InitForm IS
BEGIN
  -- switch the log to true --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETLOG', 'true' ) ;
  -- set the baen image bckground color --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETBG', '255,255,255' ) ;
  -- Set the JFileChooser title --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_TITLE',  'Select an image file' ) ;
  -- Set the JFileChooser L&F --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_LAF', 'SYSTEM' ) ;
  -- scalling properties --
  Set_Custom_Property('BLZ.BEAN',1,'SCALE_IMAGE','Width=FIT,Height=FIT' ) ;
  -- display scrollbars policy --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETSCROLL',  'false' ) ;  
END;

Here is the description of the database table used:

CREATE TABLE PHOTOS
   (   
      "IDENTIFIANT" NUMBER(5,0) NOT NULL ENABLE,
      "NOM" VARCHAR2(50 BYTE),
      "PHOTO" BLOB,
      "PHOTO_JAVA" BLOB,
      CONSTRAINT "PHOTO_PK" PRIMARY KEY ("IDENTIFIANT") ENABLE
   )
/



The properties you can get from the JavaBean


Get the image size

Varchar2 := Get_Custom_Property( 'BL.BEAN', 1, 'GETSIZE' ) ;

The format returned (width,height) is like the following : 50,120



Get the selected filename (JFileChooser)

Varchar2 := Get_Custom_Property( 'BL.BEAN', 1, 'GET_FILE_NAME' ) ;

this method both displays the JFileChooser and returns the selected file.

Get the current image chunks

Varchar2 := Get_Custom_Property( 'BL.BEAN', 1, 'GETIMAGE' ) ;

This method returns the last image read by the READIMGFILE() method..
It returns null when the image is completly read.

The events raised to Forms

Two events are raised by the Java Bean to Forms:

MOUSE_CLICKED and MOUSE_DOUBLECLICKED that you can trap through the When-Custom-Item-Event trigger:

DECLARE
    eventName varchar2(30) := :system.custom_item_event;
    eventValues ParamList;
    eventValueType number;
BEGIN
   IF (eventName='MOUSE_DOUBLECLICKED') THEN
      Message('Mouse double-click',no_acknowledge);
   ElsIF (eventName='MOUSE_CLICKED') THEN
      Message('Mouse click',no_acknowledge);
   END IF;
END;

The sample dialog


     . Download the handleimage3.zip file
     . Unzip the file
     . run the create_table.sql script under the Oracle user you want to test (It creates the sample image table).
     . run the PKG_READ_BLOB_IMAGE.sql script under the Oracle user you want to test (It creates the database package).
     . copy the handleimage3.jar file in the <ORACLE_HOME>/forms/java directory
     . Edit your /forms/server/formsweb.cfg file to add the handleimage3.jar .
     . Open the HANDLEIMAGE3.fmb module (Oracle Forms 9.0.2)
     . Compile all and run the module

Purpose

Here is a Java Bean to handle CLOB/NCLOB database columns in a Forms application.

It needs a database package to read the LOB data from the database, split into chunks in order to send them to Forms and finally to the JavaBean, and also to send back the modified text from the JavaBean to the database LOB column.

This package (PKG_CLOB), provided in the zip file, have functions and procedures to handle both CLOB and NCLOB columns.
It uses the EXECUTE IMMEDIATE function to Read and Write via full SQL orders passed as argument, so it is generic.

It has been successfully tested with Forms 10.1.2 and XE database.







The Java code

     bigtextarea.java

The implementation class of the Bean Item

     oracle.forms.fd.TextArea

The methods you can call


Add text to the text item

Set_Custom_Property('BLOCK.ITEM',1,'ADD_TEXT','text');

e.g. :

LC$Text := 'Text to send to the bean' ;
Set_Custom_Property( 'BL.BEAN', 1, 'ADD_TEXT', LC$Text ) ;   

Use this method to read the database CLOB/NCLOB content then send it to the bean.

Here is a sample code you could write in a Post-Query trigger for instance:

Declare
  LN$Length  pls_integer ;
  LC$Chunk   Varchar2(32767) ;
  LN$Cpt     pls_integer := 0 ;
  LC$Req     Varchar2(1024);
Begin    
 
  ----------------------------------
  --  Build the Select SQL order  --
  ----------------------------------
  LC$Req := 'Select NTEXT From TEST_CLOB Where ID=1' ;
 
  ---------------------------------------
  --  select the database CLOB column  --
  ---------------------------------------
  If pkg_clob.select_nclob(LC$Req) then
    Loop
      -------------------------
      --  get the chunks...  --
      -------------------------
      LC$Chunk := pkg_clob.get_nchunk ;
      Exit when LC$Chunk is null ;
      LN$Cpt := LN$Cpt + 1 ;
      --------------------------------------
      --  ... then send them to the Bean  --
      --------------------------------------
      Set_Custom_Property('BLOCK3.BEAN',1, 'ADD_TEXT',LC$Chunk);
    End loop ;
    ---------------------------------
    --  display the complete text  --
    ---------------------------------
    Set_Custom_Property('BLOCK3.BEAN',1, 'SHOW','');
    ---------------------------
    --  get the text length  --
    ---------------------------
    LN$Length := Get_Custom_Property('BLOCK3.BEAN',1,'GET_LENGTH') ;
    message('length=' || LN$Length);    
  Else
    message('problem reading CLOB');      
  End if ;
 
end;

In this sample, we are selecting  the content of the NTEXT NCLOB column from the TEST_CLOB table.


Display the complete text

Set_Custom_Property('BL.BEAN',1,'SHOW','');

Use this method when all teh text chunks have been sent to the bean.

Clear the text

Set_Custom_Property('BL.BEAN',1,'CLEAR','');

The properties you can get from the JavaBean


Get the current text length

Varchar2 := Get_Custom_Property( 'BL.BEAN', 1, 'GET_LENGTH' ) ;

Get the current text chunks

Varchar2 := Get_Custom_Property( 'BL.BEAN', 1, 'GET_TEXT' ) ;

Use this method in a loop to get every chunk, then store them in the corresponding CLOB/NCLOB database column.

Here is a sample  code you can use in a Post-Insert or Post-Update trigger:

Declare
    LC$Chunk  Varchar2(32767) ;
    LC$Req    Varchar2(1024) ;
    LC$Msg    Varchar2(4000);
Begin  
    --------------------------------
    --  set the UPDATE SQL order  --
    --------------------------------
    LC$Req := 'Update TEST_CLOB Set NTEXT = :1 Where ID=1' ;
    -------------------------------------
    --  Init the transfer for a NCLOB  --
    -------------------------------------
    PKG_CLOB.Init_Transfer ( 'NCLOB' );
    Loop
      LC$Chunk := Get_Custom_Property('BLOCK3.BEAN',1,'GET_TEXT') ;
      Exit When  LC$Chunk Is Null ;
      ---------------------------------------
      --  Send the chunks to the database  --
      ---------------------------------------
      PKG_CLOB.Set_NChunk ( LC$Chunk ) ;
    End loop;
    ---------------------------------------------
    --  Update the CLOB/NCLOB database column  --
    ---------------------------------------------
    LC$Msg :=  PKG_CLOB.Transfer( LC$Req, 'NCLOB' ) ;
    If LC$Msg = 'OK' Then
     Forms_ddl('Commit') ;
    Else
         Message(LC$Msg);
    End if ;
End;

The writting process is done through three steps:

• init the transfer by cleaning the target CLOB/NCLOB package's variable with Init_Transfer()
• send the chunks to the database package to populate the package CLOB/NCLOB variable with Set_Chunk()
• update the database row with the current CLOB/NCLOB variable with Transfer()

The sample dialog


     . Download the bigtextarea.zip file
     . Unzip the file
     . copy the bigtextarea.jar file in the <ORACLE_HOME>/forms/java directory
     . Edit your /forms/server/formsweb.cfg file to add  bigtextarea.jar .
     . If needed, create the database sample table (create_table_test_clob.sql)
     . create the database package (pkg_clob.sql)
     . Open, compile and run the BIGTEXT.fmb module (Oracle Forms 9.0.2)

Purpose

Here is a Java Bean that allows reading, displaying with scaling and writing images.

(See the last  evolution of this solution here)

This Bean allows scaling images to fit the target item size, and includes a FileChooser with image preview dialog.




This JavaBean connects to the database through the JDBC driver to read and write the images, and does not need the Webutil library to pick up the image files from the JAR file, the client machine files or the Internet.


The Java code

     HandleImage.java     LectureBlob.java        GetImageFileName.java



The implementation class of the Bean Item

     oracle.forms.fd.HandleImage


The methods you can call


Set the connection string

Set_Custom_Property('BLOCK.ITEM',1,'SETCONN','the_connection_string');
e.g. :
Set_Custom_Property( 'BL.BEAN', 1, 'SETCONN', 'jdbc:oracle:thin:@my-machine:1521:XE' ) ;   
(Provide the complete jdbc:oracle:thin:... syntax)


Set the username

Set_Custom_Property('BLOCK.ITEM',1,'SETUSER','username');


Set the password

Set_Custom_Property('BLOCK.ITEM',1,'SETPWD','password');


Set the database image table information

Set_Custom_Property('BLOCK.ITEM',1,'SETTABLEINFO','p1,p2');

p1 is the table name that holds the image Blob column
p2 is the Blob column name that holds the image

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'SETTABLEINFO', 'PHOTOS,IMAGE' ) ;  

The instruction above indicates that the PHOTOS table handle images in the IMAGE Blob column..


Read an image from a file

Set_Custom_Property('BLOCK.ITEM',1,'READIMGFILE','the_complete_filename');

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGFILE', 'D:/image.jpg' ) ; 


Read an image from the database table

Set_Custom_Property('BLOCK.ITEM',1,'READIMGBASE,'where_clause');

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGBASE', 'IDENTIFIANT=20' ) ;  

where_clause is the SQL clause to identify a unique row to update in the table. The above instruction will be interpreted as :

   Select IMAGE From PHOTOS Where IDENTIFIANT=20

Put this method into the When-New-Record-Instance block-level trigger


Write an image to the database table

Set_Custom_Property('BLOCK.ITEM',1,'WRITEIMGFILE','where_clause');

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'WRITEIMGBASE', 'IDENTIFIANT=20' ) ;  

where_clause is the SQL clause to identify a unique row to update in the table. The above instruction will be interpreted as :

   Update PHOTOS Set IMAGE = ? Where IDENTIFIANT=20

Put this method into the Post-Insert and Post-Update block-level triggers


Clear the image

Set_Custom_Property( 'BL.BEAN', 1, 'CLEAR' , '' ) ;

This function has to be called in a When-New-Record-Instance trigger if the record does not exist:

When-New-Record-Instance trigger:
If :PHOTOS.IDENTIFIANT is not null Then
   Set_Custom_Property( 'BLZ.BEAN', 1, 'READIMGBASE', 'IDENTIFIANT=12' ) ;
Else
   Set_Custom_Property( 'BLZ.BEAN', 1, 'CLEAR', '' ) ;
End if ;
:BLZ.IMG_SIZE := Get_Custom_Property( 'BLZ.BEAN', 1, 'GETSIZE' ) ;


Set the display image scalling

This function concerns only the image displayed. The image stored with the WRITEIMGBASE method will be the initial image.

Set_Custom_Property( 'BL.BEAN', 1, 'SCALE_IMAGE' , 'Width=x,Height=y' ) ;

Both Width and Height parameters must be transmitted

x and y can take the following values:

Any value greater than 0 that express an absolute size in pixels
the special value: FIT that extend to fit the exact size of the image panel' size
-1 that to keep the corresponding aspect ratio
0 that indicates no scale at all

Examples:

-- Scale the image to fit horizontally and vertically the image item --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SCALE_IMAGE', 'Width=FIT,Height=FIT' ) ;

-- Scale the image to 200x100 pixels --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SCALE_IMAGE', 'Width=200,Height=100' ) ;

-- Scale the image to 200 horizontal pixels and keep vertical aspect ratio --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SCALE_IMAGE', 'Width=200,Height=-1' ) ;




Display/hide the image panel' scrollbars

Set_Custom_Property('BLOCK.ITEM',1,'SETSCROLL','true|false');

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'SETSCROLL', 'true' ) ; 



Set the JFileChooser title and starting directory

Set_Custom_Property('BLOCK.ITEM',1,'SET_FILECHOOSER_TITLE','title[,directory]');

e.g.:
Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_TITLE', 'Select a file,D:/' ) ; 


Set the JFileChooser Look and Feel

Set_Custom_Property('BLOCK.ITEM',1,'SET_FILECHOOSER_LAF','SYSTEM|other_value');

e.g.:
-- use the current O.S. L&F --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_LAF', 'SYSTEM' ) ; 

-- use the Metal L&F --
Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_LAF', 'JAVA' ) ; 


Set the log mode to output the Bean messages

Set_Custom_Property( 'BLZ.BEAN', 1, 'SETLOG' , 'true|false' ) ;



In the sample dialog provided, here is the code used in the When-New-Form-Instance trigger:

PROCEDURE InitForm IS
BEGIN
  -- switch the log to true --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETLOG', 'true' ) ;
  -- set the baen image bckground color --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETBG', '255,255,255' ) ;
  -- set the JDBC connection information --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETCONN', 'jdbc:oracle:thin:@my-machine:1521:XE' ) ;
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETUSER', 'tutoforms' ) ;
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETPWD',  'tutoforms' ) ;
  -- set the image table and column name --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETTABLEINFO',  'PHOTOS,PHOTO_JAVA,IDENTIFIANT' ) ;
  -- Set the JFileChooser title --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_TITLE',  'Select an image file' ) ;
  -- Set the JFileChooser L&F --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SET_FILECHOOSER_LAF', 'SYSTEM' ) ;
  -- scalling properties --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SCALE_IMAGE' , 'Width=FIT,Height=FIT' ) ;
  -- display scrollbars policy --
  Set_Custom_Property( 'BLZ.BEAN', 1, 'SETSCROLL',  'false' ) ;  
END;

Here is the description of the database table used:

CREATE TABLE PHOTOS
   (   
      "IDENTIFIANT" NUMBER(5,0) NOT NULL ENABLE,
      "NOM" VARCHAR2(50 BYTE),
      "PHOTO" BLOB,
      "PHOTO_JAVA" BLOB,
      CONSTRAINT "PHOTO_PK" PRIMARY KEY ("IDENTIFIANT") ENABLE
   )
/



The properties you can get from the JavaBean


Get the image size

Varchar2 := Get_Custom_Property( 'BL.BEAN', 1, 'GETSIZE' ) ;

The format returned (width,height) is like the following : 50,120



Get the selected filename (JFileChooser)

Varchar2 := Get_Custom_Property( 'BL.BEAN', 1, 'GET_FILE_NAME' ) ;


This method, both open the JFileChooser dialog box, then returns the selected file.




Accessing to a remote database

Because the JavaBean is executed within an applet, it is not possible to connect to a remote database without a little adaptation:

   - first, the jar file must be signed.
   - second : you have to update the java.policy file stored in the Jinitiator directory

For example, to access to the database located on the machine-name server on the port 1524, add the following lines to the java.policy file:

C:/Program Files/Oracle/JInitiator 1.3.1.xx/lib/security/java.policy file

 permission java.net.SocketPermission "machine-name:1524-", "accept,connect,listen,resolve"; 
 
 permission java.security.AllPermission; 

The sample dialog


     . Download the handleimage2.zip file
     . Unzip the file
     . run the create_table.sql under the Oracle user you want to test (It creates the sample image table).
     . copy the handleimage2.jar file in the <ORACLE_HOME>/forms/java directory
     . Edit your /forms/server/formsweb.cfg file to add both handleimage2.jar and classes12.jar (the classes12.jar is located in the <DEV_HOME>/jdbc/lib directory. add a copy of this file in the <DEV_HOME>/forms/java directory).
     . Open the HANDLEIMAGE2.fmb module (Oracle Forms 10.1.2)
     . Compile all and run the module