Unlocking Data Access: A Comprehensive Guide to Reading Files from your Computer using PL/SQL in Oracle APEX

Welcome to my tutorial on integrating file reading capabilities into Oracle APEX using a SQL statement! Are you ready to take your application to the next level? In this step-by-step guide, I'll walk you through the process of seamlessly reading files from your computer and displaying them within your Oracle APEX application.

By following this tutorial carefully, you'll gain a solid understanding of how to incorporate this functionality into your own projects. Don't worry about complex coding or intricate steps – all you need to do is copy and paste the provided code, making minor modifications to the elements highlighted in red.

Throughout this tutorial, I'll ensure that each instruction is clear and easy to follow, eliminating any potential roadblocks. By the end, you'll have the knowledge and confidence to effortlessly integrate file reading into your Oracle APEX application, opening up a world of possibilities for data enrichment.

So, let's get started! Follow along closely, and soon you'll be harnessing the power of reading files from your computer within Oracle APEX. Get ready to revolutionize your application with this essential feature. Let's dive in!

Step 1: Secure Login and Execution of Code in SQL*Plus (IMPORTANT) In this step, we'll ensure a secure login to SQL*Plus using the "sys" account and execute the provided code, laying the foundation for integrating file reading capabilities in Oracle APEX.

CONN sys/Password@//localhost:1521/orclpdb AS SYSDBA

 

Step 2: Executing Statements and Granting Privileges After successfully logging in, execute two regular SQL statements followed by granting the necessary privileges to ensure a smooth integration of file reading capabilities in Oracle APEX.

EXEC DBMS_JAVA.grant_permission('TEST', 'java.io.FilePermission', '<>', 'read');

EXEC DBMS_JAVA.grant_permission('TEST', 'SYS:java.lang.RuntimePermission', 'readFileDescriptor', '');

GRANT JAVAUSERPRIV TO TEST;

Step 3: Assigning Important Roles and Logging in as User TEST In this step, we will assign all the necessary important roles to the user "TEST" and proceed to log in using the TEST account, ensuring the required privileges for seamless file reading integration in Oracle APEX.

CONN test/Password@//localhost:1521/orclpdb

Step 4: Copying and Pasting the Code In this step, simply copy and paste the provided code without making any modifications. This code snippet will enable the seamless reading of files from your computer and displaying them within Oracle APEX using a SQL statement.

CREATE OR REPLACE AND COMPILE JAVA SOURCE NAMED "FileListHandler" AS

import java.lang.*;

import java.util.*;

import java.io.*;

public class FileListHandler

{

public static String list (String path) {

String list = "";

File myFile = new File (path);

String[] arrayList = myFile.list();

Arrays.sort(arrayList, String.CASE_INSENSITIVE_ORDER);

for (int i=0; i < arrayList.length; i++) {

// Prevent directory listing expanding if we will blow VARCHAR2 limit.

if ((list.length() + arrayList[i].length() + 1) > 32767)

break;

if (!list.equals(""))

list += "," + arrayList[i];

else

list += arrayList[i];

}

return list;

}

};

/

show errors java source "FileListHandler"

CREATE OR REPLACE PACKAGE file_list_api AS

FUNCTION list (p_path IN VARCHAR2) RETURN VARCHAR2

AS LANGUAGE JAVA

NAME 'FileListHandler.list (java.lang.String) return java.lang.String';

END file_list_api;

/

SHOW ERRORS

CREATE OR REPLACE TYPE t_varchar2_arr AS TABLE OF VARCHAR2(500);

/

CREATE OR REPLACE FUNCTION get_files (p_dir IN VARCHAR2)

RETURN t_varchar2_arr PIPELINED

AS

l_array APEX_APPLICATION_GLOBAL.vc_arr2;

l_string VARCHAR2(32767);

BEGIN

l_array:= APEX_STRING.string_to_table(FILE_LIST_API.list(p_dir), ',');

FOR i in 1..l_array.count LOOP

PIPE ROW(l_array(i));

END LOOP;

RETURN;

END;

/

Step 5: Wrapping Up - Testing with PL/SQL or SQL Congratulations on reaching the final step! Now it's time to put everything to the test. Choose either PL/SQL or SQL, and run the necessary commands to validate the file reading functionality in Oracle APEX.

DECLARE

l_array APEX_APPLICATION_GLOBAL.vc_arr2;

l_string varchar2(2000);

BEGIN

l_array:= APEX_STRING.string_to_table(FILE_LIST_API.list ('/u01/app/oracle/diag/rdbms/cdb1/cdb1/trace'), ',');

FOR i in 1..l_array.count LOOP

DBMS_OUTPUT.put_line('Array(' || i || ') : ' || l_array(i));

END LOOP;

END;

SELECT column_value AS file_name

FROM TABLE(get_files('/u01/app/oracle/diag/rdbms/cdb1/cdb1/trace'));

Step 6: Optional - Creating a View to Define a Fixed Path If you find it necessary, you can create a view in Oracle APEX to define a fixed path for reading files. This step will provide you with a convenient and standardized way to access files, ensuring consistent and reliable file retrieval within your application.

CREATE OR REPLACE VIEW trace_files_v AS

SELECT column_value AS file_name

FROM TABLE(get_files('/u01/app/oracle/diag/rdbms/cdb1/cdb1/trace'));

Step 7: Conclusion - Gain File Visibility Congratulations! You have successfully completed the tutorial. Now, you have the capability to view and access all the files located on your computer within your Oracle APEX application. Enjoy the enhanced functionality and leverage the power of seamless file integration in your projects.