A file collection showing use of dummy data class.

DummyData.java

package com.example.data;

import java.util.ArrayList;

public class DummyData {

    /**
     * An {@link ArrayList} to store data.
     */
    private static ArrayList<Model> mData;

    /**
     * Private constructor to prevent instantiation
     */
    private DummyData() {
    }

    /*
     * This code block runs when the class is loaded. Initialize any data here.
     */
    static {

        // Initialize objects
        mData = new ArrayList<>();

        // Add data manually to get diverse data
        mData.add(new Model("String A", 13, true));
        mData.add(new Model("String B", 53, false));
        mData.add(new Model("String C", 119, true));

        // Or just use a loop to generate monotonous data
        for (int i = 0; i < 10; i++) {
            String string = "String " + i;
            mData.add(new Model(string, i, (i % 2 == 0)));
        }
    }

    /**
     * Returns {@link Model} data.
     *
     * @return ArrayList of Model objects.
     */
    public static ArrayList<Model> getData() {
        return mData;
    }
}

Main.java

package com.example.data;

import java.util.ArrayList;

public class Main {
    
    public static void main(String[] args) {
        // You can use the DummyData class anywhere in the app now. The data provided by DummyData will be consitent.
        ArrayList<Model> modelArrayList = DummyData.getData();
    }
}

Model.java

package com.example.data;

public class Model {

    private String mStringData;

    private int mIntData;

    private boolean mBoolData;

    public Model(String stringData, int intData, boolean boolData) {
        mStringData = stringData;
        mIntData = intData;
        mBoolData = boolData;
    }

    public String getStringData() {
        return mStringData;
    }

    public void setStringData(String stringData) {
        mStringData = stringData;
    }

    public int getIntData() {
        return mIntData;
    }

    public void setIntData(int intData) {
        mIntData = intData;
    }

    public boolean isBoolData() {
        return mBoolData;
    }

    public void setBoolData(boolean boolData) {
        mBoolData = boolData;
    }
}