How to use variables for each object

Question

I have an array of elements. I am making object on the basis of each elements name and call some getter functions. The object of the class that i am making is actually a third party library, "Sigar".

The problem is i don't want to modify this third party library, because of which i am not able to keep variables values separate for each object. I need come up with some way to keep separate variable separate for each object.

I hope my description explains what i want. Following is my code

private long lastDiskCheck = 0;
private long lastDiskRead = 0;
private long lastDiskWrite = 0;
private String getDiskUsage() {
    try {
        List<FileSystem> result = new ArrayList<FileSystem>();
        org.hyperic.sigar.FileSystem[] fss = null;
        fss = sig.getFileSystemList();
        List<Integer> diskUsage = new ArrayList<Integer>();
        String ioStat = "";
        for (int i = 0; i<fss.length; i++) {
            FileSystem fs = fss[i];
            FileSystemUsage usage = sig.getFileSystemUsage(fs.getDirName());
            if (lastDiskCheck!=0) {
                long diff = (nanoTime() - lastDiskCheck)/1000000;
                long diffRead = usage.getDiskReadBytes() - lastDiskRead;
                long diffWrite = usage.getDiskWriteBytes() - lastDiskWrite;
                ioStat = String.format("(%d/%d kB/s)", diffRead/diff, diffWrite / diff);
            }
            lastDiskRead = usage.getDiskReadBytes();
            lastDiskWrite = usage.getDiskWriteBytes();
            lastDiskCheck = nanoTime();
            diskUsage.add((int)(usage.getUsePercent()*100));
        }
        return String.format("%d%% %s", (Collections.max(diskUsage)), ioStat);
    } catch (SigarException e) {
        e.printStackTrace();
    }
    return "n/a";
}

the three variables

private long lastDiskCheck = 0;
private long lastDiskRead = 0;
private long lastDiskWrite = 0;

updates for each object inside the loop which i don't want. How can i keep it different for each object?

You can create a class which keeps your object and these 3 values. — xxlali, Sep 30 '15 at 11:28

xxlali · Accepted Answer · 2015-09-30T12:03:09.300

1

public class MyClass {
    private long lastDiskCheck;
    private long lastDiskRead;
    private long lastDiskWrite;

    private YourObject object;

    public void setLastDiskCheck(lastDiskCheck){ // setter of lastDiskCheck
        this.lastDiskCheck = lastDiskCheck;
    }

    public long getLastDiskCheck(){ //getter of lastDiskCheck
        return lastDiskCheck;
    }
}

With this methodology, you can keep each object in your MyClass and keep different value for each.

edited Sep 30 '15 at 12:03

answered Sep 30 '15 at 11:33

xxlali

996
2
15
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I am actually very new with java. I have some confusions i would really appreciate if you can give me some more detailed sample. I am confused how would i interact with this new class. – Shaonline Sep 30 '15 at 11:37
you will generate your objects with this new class. and you will set each value and do your operations with this. – xxlali Sep 30 '15 at 11:45
you mean by "with this new class" of this new class? can you give me an example of the setter please? i would really appreciate that. – Shaonline Sep 30 '15 at 12:00
I guess i was overthinking i did work thanks a lot for your time :) – Shaonline Sep 30 '15 at 12:50
Can you check this out please http://stackoverflow.com/questions/32871480/how-to-manage-variables-for-multiple-objects – Shaonline Oct 01 '15 at 08:13

score 1 · Answer 2 · edited May 23 '17 at 12:22

1

Well, in your case. You should study the 4 pillars of Object Oriented Programming in Java: http://learn2geek.com/4-pillars-oop-java/

After that, you understand how to create different instances and if you have a programming knowledge, you will not have any problem.

Moreove, to clarify and answer your problem. The best solution is to create a class with private attributes. You will access these attributes with getters/setters methods (public modifier). Indeed, you could create some objects and you could introduce and receive values of each object with the getters and setters.

Brief explanation: How do getters and setters work?

edited May 23 '17 at 12:22

Community

1
1

answered Sep 30 '15 at 12:15

Braisly

385
3
13

my confusion which i can't clear is, if i declare these properties in a new class it will be the properties of that class and objects of that class. i have set a new class DiskMembers with setters and getters. But still i don't know how can i interact with this new class. – Shaonline Sep 30 '15 at 12:37
Example: DiskMembers arrayTest[] = new DiskMembers[3]; arrayTest[0].setName("Charlie"); arrayTest[1].setName("Robert"); arrayTest[2].setName("Mario"); Now, each time that you call getName, you receive different name for the differents objects. Do you understand me? The previous "code", is a random example with random setters. – Braisly Sep 30 '15 at 12:57
Yes i do. That's helpful :), Thanks. – Shaonline Sep 30 '15 at 13:18
Could you please check this out http://stackoverflow.com/questions/32871480/how-to-manage-variables-for-multiple-objects – Shaonline Sep 30 '15 at 16:42

How to use variables for each object

2 Answers2