Application Development A Cocktail of Java and MCP. MCP Guru Series Dan Meyer & Pramod Nair

(1)

Application Development

A

Cocktail of Java and MCP

MCP Guru Series

(2)

Agenda

Which of the following topics can be found in an Application

Development cocktail?

o

Calling Java from COBOL-85

o

Using Java7 NIO2 features

o

Accessing DMSII from Java

o

All of the above

o

Some of the above

(3)

“A Cocktail of Java and MCP”

(4)

Application Development

•

“Wouldn’t It Be Nice” by the Beach Boys

“Wouldn't it be nice if we were older

Then we wouldn't have to wait so long

Wouldn't it be nice to live together

In the kind of world where we belong

You know its gonna make it that much better

When we can say goodnight and stay together”

•

Wouldn’t it be nice if:

–

Your favorite programming language could be used for everything?

–

You could find libraries that could be easily called and not support?

–

There were an endless supply of COBOL programmers?

(5)

Mixing Languages Through Libraries

•

We Invented It Application Program Interface (Wii API)

–

A “was well documented”, in-house developed standard

–

Specific application during definition

–

Communication over TCPIP (Socket-to-Socket)

•

Common Object Request Broker Architecture (CORBA)

–

A well-defined Object Management Group (OMG) standard

–

Vendor-independent architecture and structure

–

Communication over the Internet Inter-Orb Protocol (IIOP)

•

Java Native Interface (JNI)

–

A well-defined Java standard

–

Defined for C

(6)

COBOL



????

•

COBOL app needs to access an Oracle database

•

COBOL app needs to be web services enabled

•

COBOL app needs to create a PDF file

•

COBOL app needs to decrypt messages encrypted with …

(7)

Java Invocation Interface (Jii)

•

COBOL-85 (via ALGOL) calling Java methods

•

Can invoke standard Java packages

•

Usually need minimal Java code

•

Native program is in control

•

Uses Java as a private library

(8)

Java Invocation Interface (Jii)

•

API developed to call Java methods

–

Simplified with “com.unisys.mcp.tools.JifGen”

•

Reads Java source or class and generates “entrypoint” INCLUDE file

•

Does all the ‘dirty work’ of calling JNI methods

–

Based on C JNI method definition in a generated ALGOL library

•

Calls for identifying methods by name

•

Calls for identifying objects by name

•

Chatty and “error prone”

JNI Proxy Lib JProcessor Java Worker Java Worker JVM Application JNI Interfaces Java Class

(9)

Jii Development Process Demo

•

Create or identify a Java class with public methods

– Demo – COBOL program needing to accessing ‘remote’ database using data from a DMSII database

– Java application needs 3 methods

• Connect to the remote database – getConnection()

• Close database connection – releaseConnection()

• Retrieve record using key passed from COBOL-85 and compare data – compareEqual (int id, String word)

UniverseDemo.zip

(10)

Jii Development Process Demo

package com.unisys.mcp.universe; import java.sql.*;

public class Demo {

static Connection con = null;

static PreparedStatement pStmt = null;

static String url = “jdbc:unisys:dmsql:Unisys.DMSII”; public static boolean releaseConnection()

{

try {

if (pStmt <> null) pStmt.close(); if (con <> null) con.close();

return true;

} catch (SQLException seq) { sqe.printStackTrace(); return false;

} }

(11)

Jii Development Process Demo

public static boolean getConnection() {

boolean onMCP = System.getProperty("os.name").contains("MCP"); String hostname = onMCP ? “EVLANMCP” : “ECCSK”;

try {

Class.forName ("com.unisys.jdbc.dmsql.Driver“) url = url + “resource=UNIVERSEDB;”

+ “host=“ + hostname + “;port=1897” + “user=JAVA;password=JAVA”);

con = DriverManager.getConnection (url); if (con == null) return false;

pStmt = con.prepareStatement

("SELECT * FROM universedb.words “ + “ where word_id = ?");

if (pStmt == null) return false; return true;

} catch (SQLException sqe) { sqe.printStackTrace();

return false; }

(12)

Jii Development Process Demo

public static boolean compareEqual (int id, String wordA) { wordA = wordA.trim(); try { pStmt.setInt(1, id); ResultSet rs = pStmt.executeQuery(); if (rs.next() { String a = rs.getString(“dmsii_word_a”); if (a.compareTo(wordA) != 0) {

System.err.println (id + “) “ + a + “<>” + wordA); return false;

}

} else {

System.err.println (id + “) not found [“+ wordA +”]”); return false;

}

return true;

} catch (SQLException sqe) { sqe.printStackTrace(); return false;

(13)

Jii Development Process Demo

public static void main (String args[]) {

String command = “select * from dmsii_words”); try {

if (getConnection()) {

Statement stmt = con.createStatement(); ResultSet rs = stmt.executeQuery(command); while (rs.next()) {

int id = rs.getInt (“word_id”);

String wordA = rs.getString (“dmsii_word_a”);

Initialize-JVM.

STRING jvmOptions, jvmCP1, jvmCP2, jvmCP3, jvmCP4 DELIMITED BY SIZE INTO ARGUMENTS.

ADD FUNCTION Length ( jvmOptions ), FUNCTION Length ( jvmCP1 ), FUNCTION Length ( jvmCP2 ), FUNCTION Length ( jvmCP3 ), FUNCTION Length ( jvmCP4 ) GIVING ArgLength.

MOVE MCP-Options TO Arguments-2.

MOVE FUNCTION Length ( MCP-Options ) to Arg2Length. CALL JNI-CREATE-JAVA-VM

USING JNI-VM, JNI-ENV, Interface-Version, ARGUMENTS, ArgLength ARGUMENTS-2, Arg2Length GIVING RESULT. CALL INITIALIZE-DEMO USING JNI-ENV. CALL DEMO-DEMO-GET-CONNECTION USING JNI-ENV, bRESULT.

(18)

Jii Development Process Demo

OPEN INQUIRY UNIVERSEDB ON EXCEPTION GO TO XIT. loop-it.

FIND WORD VIA NEXT IDX-WORDS ON EXCEPTION GO TO XIT. MOVE DMSII-WORD-A TO DataWord.

MOVE WORD-SZ TO WordSz.

CALL DEMO-DEMO-COMPARE-EQUAL

USING JNI-ENV, WORD-ID, DataWord, WordSz, bRESULT. IF NOT bRESULT THEN

DISPLAY "COMPARE STRING ERROR=", bRESULT. GO loop-it.

xit.

(19)

Jii Possibilities?

•

Calling

Bouncy Castle

Crypto API

•

Accessing JBoss through its

Java Naming and Directory

Interface (JNDI)

•

Accessing third-party databases

•

Creating thumbnails of images

•

PDF Generation

•

Creating JSON data files

•

Using “off-the-shelf” components written in Java

(20)

Guidelines for Calling Java

•

Calling Java from native code is complicated and tedious.

•

Crossing between MCP and the Java environment is

expensive.

•

Try to write “heavy” functions.

•

Pass everything as parameters rather than calling back for

more information.

(21)

Java Docs Main Page

Virtual Machine for the

Java™ 6.0 Platform

on ClearPath MCP

Programming Guide

Installation and Administration Guide

ClearPath Common Appliance Configuration Guide

JVM for MCP API Specification

Java Native Interface for MCP

Readme, Errata and Other Notes

Optimizing Java Socket Performance

(22)

“A Cocktail of Java and MCP”

(23)

Java 7

•

Java SE 7 – Available with MCPJAVA in 15.0

•

New I/O features:

–

Asynchronous I/O

–

Ability to extend and customize the I/O interface.

•

For MCP this means:

(24)

Java 7 Example

import java.nio.file.*;

import com.unisys.mcp.file.*;

import static com.unisys.mcp.file.InitialFileAttributes.*;

…

Path file = FileSystems.getDefault().getPath( args[0] );

file.createFile(

FileKind.COBOL85SYMBOL.asFileAttribute(),

FileClass.RECORDORIENTED.asFileAttribute(),

maximumRecordSize(80),

(25)

Java 7 Example

•

Copies a file identified by the “file” path at ECCSK to

the local host as the file identified by the destination

path.

•

Uses MCP copy operation (BNA, FTP).

•

Similar moveTo will change the file name, if possible;

otherwise copy and delete the original.

file.copyTo( destination,

StandardCopyOption.ReplaceExisting,

McpCopyOption.Recursive,

(26)

McpFileAttributes Class

•

Provides most MCP attributes for a file.

•

All the various time stamps.

•

Title

•

Note

(27)

File Attributes

areaLength

accessTimestamp

fileClass

areas

alterTimestamp

fileKind

blockSize

attributeModifyTimestamp

fileName

clearAreas

backupTimestamp

fileStructure

compilerKind

copyDestinationTimestamp

frameSize

ccsVersion

copySourceTimestamp

hostName

extMode

creationTimestamp

licenseKey

familyIndex

executeTimestamp

note

familyName

openTimestamp

pathName

sensitiveData

readTimestamp

product

userInfo

maximumRecordSize

title

(28)

Open Options

•

Specify any of these when opening a file.

File Options

Record Options

Buffers

Fold

BufferSize

IncludeSequenceNumbers

HostName

NoCrLf

IntName

StripSpaces

Truncate

Unfold

(29)

Initial File Attributes

•

Specify any of these when creating a file.

areaLength

areas

blockSize

clearAreas

familyIndex

frameSize

hostName

maximumRecordSize

note

sensitiveData

userInfo

(30)

Java Docs Main Page

Virtual Machine for the

Java™ 6.0 Platform

on ClearPath MCP

Programming Guide

Installation and Administration Guide

ClearPath Common Appliance Configuration Guide

JVM for MCP API Specification

Java Native Interface for MCP

Readme, Errata and Other Notes

Optimizing Java Socket Performance

(31)

“A Cocktail of Java and MCP”

(32)

Accessing DMSII From Java

DMSII Databases

D

M

S

Q

L

(33)

Accessing DMSII From Java

•

COBOL & ALGOL access via Host Language constructs

–

OPEN, FIND/LOCK, CREATE, STORE, …

–

BEGIN-TRANSACTION, END-TRANSACTION, …

•

Java access

–

Java Host Language Interface (JHLI) and Java DMInterface (JDMI)

–

Java EE Connector Architecture (JCA) components

•

Resource Adapters

– MCP Transaction Resource Adapter (JRAC)

– Open Distributed Transaction Processing Resource Adapter (DTP-RA)

–

Java Database Connectivity (JDBC)

•

Resource adapters based on JCA

•

Structured Query Language (SQL) based

(34)

Querying DMSII using JDBC SQL Client Tools

(35)

DMSII-JDBC @ GSA

ClearPath

MCP

SQL Query Processor for ClearPath MCP DMSII

JProcessor

Presentation Tier/ Business Tier JSF/RichFaces POJO

JDBC

Drive

r

(36)

Summary

•

Invocation interface lets ALGOL or COBOL program call

Java libraries.

•

Java 7 will allow tighter file system integration.

•

Consider the alternatives for accessing a DMSII database

from Java

(37)

Bouncy Castle

Java Naming and Directory Interface (JNDI)

http://www.componentsource.com/features/java-components/index.html