I had been using Netbeans since I started programming and every time I wanted something done (downloading CSV from online, scan a file and paste it into another file, etc.), I just create a JButton and put and make it an action event, it is very easy with NetBeans GUI since i can just right click on the button and click Action Performed, and all the codes will be written for me.
That worked very well until a week ago, when one method can contain up to 10,000 lines of codes (I am not joking). So that's 1 month of work down the drain and I decided to start from scratch. Regardless, the 1 month helped since it was my first program and I did not even understand what a "method" or "class" is. (Irrelevant but funny, my previous code contains 18,000 lines and it is all written on one page because I have no idea how to call another method from another class).
Now I know that if I wanted to call a method from another class, I can just write: test.calculation() to access the method calculation() from test's class.
But now I ran into another problem, it seems like the purpose of calling another method is to get the return value of that method. I am currently working on writing a method which will run different things depending on the integer, and I have a feeling that it will goes up to 100+. The if statement would look like this:
if(ID == 1){do task number 1;}
if(ID == 2){do task number 2;}
....
if(ID == 100){do task 100;}
I am on task number 1, which involves downloading files from websites and editing them, the code for task number 1 is around 120 lines.
I am planning on making a new Java Class which does specifically that task, so instead of having 120 lines of code I can just have one code, something like this:
if(ID == 1){call class/method to do task};
But I am running into a few problems that I believe does not solve the root cause, some errors include non static cannot be referenced in static etc...
All I wanted task number 1 to do is to download a file and edit it. Anything is appreciated.
Thanks in advance.
Related
We have a test where basically we need to input a specific value in a web site and make sure another value comes out. The data of the input-output for this is stored in an XML file.
Now we can create a single Scenario that runs once and loops through, submitting each value however we run into some reporting problems, if 2 out of 100 pairs fail we want to know which ones and not just have an assertion error for the whole scenario.
We would get much clearer reporting using a Scenario Outline where all the values are in the examples table. then the scenario itself runs repeatedly and we can fail an individual set as an assertion error and have that kick back clearly in a report.
Problem: we do not want to hard code all the values from the xml into the .feature. it's noisy but also if the values change it's slow to update. we would rather just provide the XML parse it and go, if things change we just drop in an updated XML.
Is there a way to create dynamic examples where we can run the scenario repeatedly, one for each data case, without explicitly defining it in the examples table ?
Using Cucumber for this is a bad idea. You should test this functionality lower down your stack with a unit test.
At some point in your code, after the user has input their value, the value will be passed to a method/function that will return your answer. This is the place to do this sort of testing.
A cucumber test going through the whole stack will upwards of 3 orders of magnitude slower than a well written unit tests. So you could test thousands of pairs of values in your unit test in the time it takes to run one single cuke.
If you do this sort of testing in Cucumber you will quickly end up with a test suite that takes far too long to run, or that can only be run quickly at great expense. This is very damaging to a project.
Cuking should be about one happy path (The user can enter a value and see the result) and maybe a sad path (the user enters a bad value and sees an error/explanation). Anything else needs to be pushed down to unit tests.
The NoraUi framework does exactly what you want to do in your project. The NoraUi code is open source. If you have questions about this framework, you can post an issue with the tag "Question"
I have JAVA SDK files to interact with a third party software.
My goal is to receive the data sampled by my RaspPi sensors online/live and pass it to this software.
The issue is that, I want to run the scripts individually (each sensor has it own python code file), because of different time cycle (sample,calc....) of everyone of the sensors.
the script are in form of:
Initialization of GPIO
Functions declarations
Var declaration
Infinite LOOP of sampling, calculating (by functions) & printing new line (the data) to screen - usually a floating number.
For now, as I understand, I need to start the python once at start of my java, by thread/process/sub-process.... while every time new line printed it supposed to parse to AtomicInteger. and that continue running on background.
Then on the Java I have another infinite loop that inside:
1."get" each one of the AtomicIntegers.
2."pass" it..
and again "get" -> "pass" (this loop while have one second cycle).
this is my first time asking a question, i hope i explained myself correctly :)
thanks in advance to all answers.
Gil
Eclipse is awesome for writing java programs but today I find that it's awesome to trick new coders like me. #_#
I write a snippet as following,
public static void main(String[] args) {
for(int i=0;i<3;i++){
System.out.println("i = " + i);
}
}
then I add a breakpoint at the line of "System.out.print....", click "Debug" button, eclipse goes to the "Debug" perspective and the line of breakpoint is highlighted, then I move the cursor over variable "i", its value is "0" as expected.
And then, I select the "i++" and click "Inspect"(or press "Ctrl+Shift+I") once, I move the cursor over variable "i", its value changed to "1". I repeat "Inspect" again, the value of i changed to "2"......(its value will add by 1 every time I clicked the "Inspect")!!
Why does this happend!? I ONLY want to watch the value of "i" for debug propuse, DO NOT want to really change its value until I step into next statement. I think that "Inspect", as well as "Display" are only for viewing the variable/expression, they should not impact the value, but in this case, it doesn't work as I expect to.
Could anyone tell me what went wrong?
My eclipse version info:
Version: Indigo Service Release 2
Build id: 20120216-1857
If you inspect an expression, eclipse has to execute that expression so you can get the value. Therefore, if you inspect i++, eclipse adds one to i.
Think about it this way: If instead of i++, you inspected myFunction(i), would you expect eclipse to execute the function "myFunction" to get the value? It's the same with i++.
If you are concerned about displaying/showing values while debugging and do you want to be sure not affecting the value, you should select the variable or expression and use the "Watch" option.
This will track the variable/expression value without executing, just updating the new value each time this is run. I think is the most secure way.
As Pablo mentioned, it has to evaluate the code in order to tell you what value it returns. You could instead put a watch on "i+1" and that would give you the value you want without the side effect you don't want.
Basically, you need to be aware of any side effects of anything you launch, whether from the "main" code or from the debugging tools. As Erhannis mentioned, this is very useful at times for modifying values while debugging your code. (For example, you can verify that a tweak/fix is indeed helpful before actually tweaking your code.)
You were expecting "an isolate area" but this would be extremely hard to do, especially in an object-oriented context where many objects are linked to many other objects. Running the whole thing in parallel might sometimes work, but you'd lose the tweaking ability above. And in any context, you'd run into tons of problems with fighting over resources; e.g. both copies trying to read/write a particular file such as a log file. Also, the two execution paths could diverge, leading to incorrect/misleading watch values.
So, preventing such side effects is not really a feasible option here and would rarely be useful anyway. Just expect that the watches can both reflect and affect the code execution.
The Problem:
I have numerous files that contain Apache web server log entries. Those entries are not in date time order and are scattered across the files. I am trying to use Pig to read a day's worth of files, group and order the log entries by date time, then write them to files named for the day and hour of the entries it contains.
Setup:
Once I have imported my files, I am using Regex to get the date field, then I am truncating it to hour. This produces a set that has the record in one field, and the date truncated to hour in another. From here I am grouping on the date-hour field.
First Attempt:
My first thought was to use the STORE command while iterating through my groups using a FOREACH and quickly found out that is not cool with Pig.
Second Attempt:
My second try was to use the MultiStorage() method in the piggybank which worked great until I looked at the file. The problem is that MulitStorage wants to write all fields to the file, including the field I used to group on. What I really want is just the original record written to the file.
The Question:
So...am I using Pig for something it is not intended for, or is there a better way for me to approach this problem using Pig? Now that I have this question out there, I will work on a simple code example to further explain my problem. Once I have it, I will post it here. Thanks in advance.
Out of the box, Pig doesn't have a lot of functionality. It does the basic stuff, but more times than not I find myself having to write custom UDFs or load/store funcs to get form 95% of the way there to 100% of the way there. I usually find it worth it since just writing a small store function is a lot less Java than a whole MapReduce program.
Your second attempt is really close to what I would do. You should either copy/paste the source code for MultiStorage or use inheritance as a starting point. Then, modify the putNext method to strip out the group value, but still write to that file. Unfortunately, Tuple doesn't have a remove or delete method, so you'll have to rewrite the entire tuple. Or, if all you have is the original string, just pull that out and output that wrapped in a Tuple.
Some general documentation on writing Load/Store functions in case you need a bit more help: http://pig.apache.org/docs/r0.10.0/udf.html#load-store-functions
I finished first year comp sci. And i want to spend some time working on the things they have taught us in the first year (lot of java and a bit of C)...
Anyways as a project, i wanted to do something i need, and what i need is a program to run through my movie folder and get the ratings and some basic info from IMDB...
I'm not sure where to start, i think i can handle the parts about reading the folder names, getting rid of the junk from the name to get the actual name and stuff.. Also i can handle the GUI but i don't know how i can talk to IMDB... what steps should i take to complete this project. I have about a month before school starts and i want to finish it before then...Thanks for all the input
EDIT:
Also can you guys tell me what i should start with and then move on to what? As in should i start with the GUI first or have the code that reads in the folder names and filters the names... I only wrote one program as an assignment in school and it was basically outlined step by step so i just wanna know what i should start with
You've made a very good start by decomposing the problem, identifying the kind of components you need and focusing on (an important) one that you don't know how to do.
The IMDB API is documented here and you can see that it amounts to sending simple HTTP requests with some paramters and getting back some formatted data, possibly as a JSON string.
You will find libraries to help with doing those two things. Even if there are public domain wrappers for accessing IMDB I'd recommend attempting to use general purpose HTTP and JSON libraries - that's probably a better educational exercise.
I'm the author of the IMDB API you are dicussing ;) I limit requests to 30 per hour to stop people hammering. I have yet to have a legitimate reason to perform more requests than that. My suggestion to anyone is to write a batch script to perform 1 request every 2minutes and then leave it going for a few hours overnight. Then you only have to perform a request on demand whenever you add a new movie.