SQL Application Express REST API client

The Application Express REST API client sample demonstrates calling an SQL query with a bind variable passed on the URL.

Client creation using com.oracle.ceal.ApexRestClient
```
apexClient=new ApexRestClient(apexRestUrl, proxy Host, proxy Port,cloud  
identityDomain, cloud username, cloud password, 
ignoreSSLCertificationPathErrors)
```
- Apex REST URL in the format: https://server
  
  Example: https://<SERVER>.oraclecloud.com/apex
- proxy host:
  - Leave empty if not using a proxy
  - If using a tool like Fiddler for HTTP captures, specify localhost.
  - If you need to go through a proxy to connect to Oracle cloud services, specify the proxy host.
- proxy port:
  - Leave empty if not using a proxy
  - If using Fiddler, use 8888.
  - Otherwise, enter your proxy port.
- Cloud identity domain: this is provided with your cloud login. You can also find this in the APEX URL.
- ignoreSSLCertificationPathErrors (true or false): Set this to true if connecting through a proxy like Fiddler.
Calling an SQL Query defined in APEX / SQL Workshop / RESTful web services

The REST web service must be created first. For more information, read this Oracle By Example: http://www.oracle.com/webfolder/technetwork/tutorials/obe/cloud/13_2/dbservice/restfulws/restfulws.html
```
apexClient.launchSQLQueryUsingGETAndVariableOnUrl("<module name>/<uri>", "<bind variable>")
```
Example:
```
apexClient.launchSQLQueryUsingGETAndVariableOnUrl("bics/test", "7839")
```
This example uses the following definition of the REST service in APEX:

RESTful Service Module: bics/ URI Template: test/{ID} Method: GET Source Type: Query Format: JSON Requires Secure Access: YES Source: Select EMPNO,ENAME,JOB,MGR,HIREDATE,SAL,COMM,DEPTNO from EMP where EMPNO = :ID

The URL call will be in the following format:

https://<SERVER>.oraclecloudapps.com/apex/bics/test/7839

The response will be in the following format:

Response Content-Type:application/json
```
{"next":{"$ref":"https://<SERVER>.oraclecloudapps.com/apex/bics/test/7839?page=1"},"items":[{"empno":7839,"ename":"KING","job":"PRESIDENT","hiredate":"1981-11-17T00:00:00Z","sal":5000,"deptno":10}]}
```

Calling a PL/SQL defined in APEX / SQL Workshop / RESTful web services

A method is available, but all the configuration work must be done in APEX.

apexClient.launchProcUsingGET("<module name>/<uri>")

The definition of the REST service in APEX is for this example:

RESTful Service Module: bics/ URI Template: plsql/ Method: GET Source Type: PL/SQL Requires Secure Access: YES Source:

DECLARE
		prevdeptno   number;
		deptloc      varchar2(30);
		deptname     varchar2(30);
		CURSOR getemps IS select * from emp 
				where ((select job from emp where ename = :empname)  IN ('PRESIDENT', 'MANAGER')) 
             			or deptno = (select deptno from emp where ename = :empname) 
             			order by deptno, ename;
		BEGIN
			sys.htp.htmlopen;
			sys.htp.headopen;
			sys.htp.title('Departments');
			sys.htp.headclose;
			sys.htp.bodyopen;
 			for emprecs in getemps
			loop
			if emprecs.deptno != prevdeptno or prevdeptno is null then
        					select dname, loc into deptname, deptloc 
       	     				from dept where deptno = (select deptno from emp where ename = emprecs.ename);
          			if prevdeptno is not null then
             				sys.htp.print('</ul>');
          end if;
          			sys.htp.print('Department ' || deptname || ' located in ' || deptloc || '<p/>');
          			sys.htp.print('<ul>');
          end if;
			sys.htp.print('<li>' || emprecs.ename || ', ' || emprecs.job || ', ' || emprecs.sal || '</li>');
			prevdeptno := emprecs.deptno;
			end loop;
			sys.htp.print('</ul>');
			sys.htp.bodyclose;
			sys.htp.htmlclose;
		END;

		URL call will be in the form: https://<SERVER>.oraclecloudapps.com/apex/bics/plsql/
		Response will be in following format for this specific plsql example
				Response Content-Type:text/html; charset=UTF-8
				<HTML>
				<HEAD>
				<TITLE>Departments</TITLE>
				</HEAD>
				<BODY>
				</ul>
				</BODY>
					</HTML>