style checker for java baile herculane, 28.8. – 3.9.2005 u. sacklowski, dept. of comp. sc.,...

Baile Herculane, 28.8. – 3.9.2005 U. Sacklowski, Dept. of Comp. Sc., HU-Berlin 1

Style checker for JAVA

A style checker for JAVA and

its application at HU

25.08.05



1. Introduction

2. How to use AssessStyle

3. Experience at HU in WS 04 /05and related work



Humboldt University Berlin1st Semester

Introduction to object-oriented programming with Java:

• lectures: 64 hours• exercises on paper: 32 hours

• lab work: Java programs

about 200 students involved,3 students work as correctors



Students final grading covers correctness and programming

style

Students final grading covers correctness and programming

style

Assessment of Java programs at HU by correctors- assistance for correctors and students final grading -

Java program

compilability correctness programming style

Javacompiler

apply theprogram topreparedtest cases

short manualinspection



Tool AssessStyle- assistance for correctors and students -

Java program

compilability correctness programming style

Javacompiler

apply theprogram topreparedtest cases

short manualinspection

ToolAssessStyle(since WS 04/05)

Source: N. Rocca Diploma thesis, supervisor: K. Bothe



• missing empty line• missing white space • wrong indentation• switch without ‘default‘• method too long• missing comment• too short identifiers• . . .

Tool ‘AssessStyle‘: Style guide checks

48 criterias (check types) of good programming style, e. g.

criterias(check types)

criterias(check types)



• White spaces and other optical aspects, e.g.missing empty linemissing white spacewrong indentation

• Statements, e. g.switch without ‘default‘

• Size, length, complexity, e. g.method too long

• Comments, e. g.missing comment

• Names and declarations, e. g.too short identifiers

Tool ‘AssessStyle‘: Style guide checks

48 criterias (checks) of good programming style in the fields, e. g.

in additional, you can group criterias

tomistake types

in additional, you can group criterias

tomistake types



How to use AssessStyle

1. Introduction

2. How to use AssessStyle1. Load Java program into the tool

2. Tool automatically checks for style guides

3. Some criteria are checked semi-automaticallyand some manually

4. Tool automatically computes a metric and a markaccording to conformance to style guidelines

5. Tool configuration




User interface of AssessStyle Set of mistake types

bad nameD



Example of AssessStyle (1) Set of mistake types

bad nameD

D



Example of AssessStyle (2)

bad nameD

D



Example of AssessStyle (3)

D




1. Introduction









There are tree kinds of checks:

automatic

semi automatic

manual

search algorithms are implemented; they are applied

generally

search algorithms are implemented;

the user decides on their application

search algorithms are not implemented; the

user can mark mistakes manually



Example of AssessStyle - manual (1)

bad name

bad commentK



Example of AssessStyle - manual (2)

bad name

bad commentK

K

drag & drop




1. Introduction









Tool computes a metric P and a mark

Parameters are:1. The weight of particular mistake-types, e. g.

missing comment 4 missing empty line 2 bad indentation 1 file too long 9

2. The relation between the mark and the values of P

P = h(f) * g(f)f F

weight of error f

number of errors fin 100 LOC

Set of all mistake-types

mark total number P

1 0 – 202 20 – 403 41 – 604 61 – 805 81 – 1006 > 100



Tool has found these mistakes




1. Introduction









1. Selection and configuration of a proper set of style errors for the lab (mistake types and detailed checks)

2. Weight of particular mistake types

3. Define the mark depending on the value of P

Tool configuration



Tool configuration (1) Set of mistake types

you can configure all these with the

tool



1. Selection and configuration of a proper set of style errors for the lab (mistake types and detail checks)

2. Weight of particular mistake types, e. g. missing commend 4 missing empty line 2 bad indentation 1 file too long 9

3. Define the mark depending on the value of P

Tool configuration (2, 3)

total number P mark

0 – 20 120 – 40 241 – 60 361 – 80 481 – 100 5> 100 6

you can configure all these whith the

tool

you can configure all these with the

tool



1. Introduction

2. How to use AssessStyle




Experience at HU in WS 04 / 05

used by correctors without too much effort used by students as a pre-check of their solutions accepted by correctors and students programming style improved during the semester



Programming style improved during the semester

Figure 1: first Java exercise

style error points (P)

a significant amount of students has a lot of style error points

den

sity

(~

stud

ents

)



Programming style improved during the semester

Figure 2: third Java exercise

style error points (P)

now, almost all students have very

few error points

den

sity

(~

stud

ents

)



Related work: style check and style assessment

Program Operating system GUI File Types Aim of application

AssessStyle independent yes Java display of style errors, assessment of style

Checkstyle independent no Java display of style errors

Artistic Style independent no C, C++, new formatting C#, Java

JStyle windows yes Java display of style errors, metrics

Praktomat web-interface web- Java, function tests and display interface C++ u. a. of style errors, manuell assisted assessment

Jalote-Prog. ? ? C assessment of style











Very good, but- commercial (1000 dollar / licence)- no assessment+ metrics (e. g. Halstead, …)











It checks very many programming style criterias and

it is open source, but- no GUI- no assessment











AssessStyle is an enhancement from Checkstyle!+ GUI+ assessment+ manual checks+ statistics, …



Thank y u f r y ur attenti n!

style checker for java baile herculane, 28.8. – 3.9.2005 u. sacklowski, dept. of comp. sc.,...

Documents

style checker

java baile herculane

style guidelines

style guides

load java program

d slide

bothe slide

related work slide