Q:

Combining native app with worklight project

I am working on a worklight application which needs file IO in it.  I have written that code in  an android project separately.  Can anyone tell me how I can combine the both of them into one?  

A:

Like Idan said, there's no way to port your existing native application to a Worklight Hybrid Application.  However, you can take advantage of the File API that works out of the box with Worklight Hybrid Applications in different environments, such as Android and iOS.  If you create a Cordova Plugin you will need to create a plugin for all the environments you wish to support. 
Here's a quick example of the File I/O API for Writing a file:
// Wait for Cordova to load
//
document.addEventListener("deviceready", onDeviceReady, false);

// Cordova is ready
//
function onDeviceReady() {
    window.requestFileSystem(LocalFileSystem. PERSISTENT, 0, gotFS, fail);
}

function gotFS(fileSystem) {
    fileSystem.root.getFile("readme.txt", {create: true, exclusive: false}, gotFileEntry, fail);
}

function gotFileEntry(fileEntry) {
    fileEntry.createWriter(gotFileWriter, fail);
}

function gotFileWriter(writer) {
    writer.onwriteend = function(evt) {
        console.log("contents of file now 'some sample text'");
        writer.truncate(11);  
        writer.onwriteend = function(evt) {
            console.log("contents of file now 'some sample'");
            writer.seek(4);
            writer.write(" different text");
            writer.onwriteend = function(evt){
                console.log("contents of file now 'some different text'");
            }
        };
    };
    writer.write("some sample text");
}

function fail(error) {
    console.log(error.code);
}

Here's an example of Reading a file:
// Wait for Cordova to load
//
function onLoad() {
    document.addEventListener("deviceready", onDeviceReady, false);
}

// Cordova is ready
//
function onDeviceReady() {
    window.requestFileSystem(LocalFileSystem. PERSISTENT, 0, gotFS, fail);
}

function gotFS(fileSystem) {
    fileSystem.root.getFile("readme.txt", null, gotFileEntry, fail);
}

function gotFileEntry(fileEntry) {
    fileEntry.file(gotFile, fail);
}

function gotFile(file){
    readDataUrl(file);
    readAsText(file);
}

function readDataUrl(file) {
    var reader = new FileReader();
    reader.onloadend = function(evt) {
        console.log("Read as data URL");
        console.log(evt.target.result);
    };
    reader.readAsDataURL(file);
}

function readAsText(file) {
    var reader = new FileReader();
    reader.onloadend = function(evt) {
        console.log("Read as text");
        console.log(evt.target.result);
    };
    reader.readAsText(file);
}

function fail(evt) {
    console.log(evt.target.error.code);
}

