add content for package,classes,variables

Author: anishmanandhar

docs/java/classes.md

@@ -6,8 +6,34 @@ sidebar_label: Classes
 
 #### The following convention should be followed for `class` naming:
 
-* Class names are generally nouns, in title-case with the first letter of each separate word capitalized. e.g.
-    - **LeaveController**
-    - **EmployeeRepository**
-    - **AttendanceRecord**
-  
+* Class names are generally nouns or nouns phrases, in title-case with the first letter of each separate word capitalized or **UpperCamelCase**. e.g.
+  - **LeaveController**
+  - **EmployeeRepository**
+  - **AttendanceRecord**
+  
+* Test classes are named starting with the name of the class they are testing, and ending with Test. For example, 
+  - **LeaveControllerTest**
+  - **AttendanceRecordTest**
+
+* Class name should be designed with single responsibility principle, self descriptive and self documenting.
+
+* Classes on various application layers should be suffixed with terms as given below
+  - Controller
+    - LeaveController
+    - ReportController
+  - Service
+    - EmployeeService
+    - LeaveCalculator
+    - ReportManager
+  - Models
+    - Leave
+    - Employee
+    - Balance
+    - Report
+  - Utils
+    - ExceptionUtils
+    - ReportBuilder (*follows builder pattern while generating report*)
+    - HTMLParser (*cases which includes acronyms, should be written as it is.*)
+  - Repository/DAO
+    - EmployeeDao
+    - LeaveRepository

docs/java/files.md

@@ -6,12 +6,15 @@ sidebar_label: Packages
 
 #### The following convention should be followed for package naming:
 
-The prefix of a unique package name is always written in all-lowercase ASCII letters and should be one of the top-level domain names, currently com, edu, gov, mil, net, org, or one of the English two-letter codes identifying countries as specified in ISO Standard 3166, 1981.
+The prefix of a unique package name is always written in **all-lowercase ASCII letters** and should be one of the top-level domain names, currently **com**, **org**,**edu**, **gov**, **mil**, **net**, or one of the English two-letter codes identifying countries as specified in ISO Standard 3166, 1981.
+
+    - Packages are all lower case to avoid conflict with the names of classes or interfaces.
+    - Special characters are not allowed while naming packages, only alphanumeric.
+    - Avoid reserve keywords
 
 Subsequent components of the package name vary according to an organization's own internal naming conventions. Such conventions might specify on technical aspect or a feature aspect e.g employee, leave, department, project etc : 
 
-
-    #### packaging by feature
+   #### packaging by feature
 
     - com.projectname.employee
     - com.projectname.leave
@@ -28,3 +31,16 @@ Subsequent components of the package name vary according to an organization's ow
     - com.projectname.factories
     - com.projectname.utils
     - com.projectname.repository
+  
+In some cases, the internet domain name may not be a valid package name. 
+This can occur if the domain name contains a hyphen or other special character, 
+if the package name begins with a digit or other character that is illegal to 
+use as the beginning of a Java name, or if the package name contains a reserved Java keyword, such as "int". 
+In this event, the suggested convention is to add an underscore. For example:
+
+|  Domain Name                 |  Package Name Prefix |
+|---                           |                    ---|
+|hyphenated-name.example.org   | org.example.hyphenated_name  |
+|example.int                   |int_.example |
+| 123name.example.com          |com.example._123name   |
+

docs/java/packages.md

@@ -4,4 +4,28 @@ title: Variables
 sidebar_label: Variables
 ---
 
-#### The following convention should be followed for variable naming:
+#### The following convention should be followed for variable naming
+
+* Variable names should be **noun** or **adjectives** and should be **camelCase**. e.g age, balance, employeeReport etc
+  
+* Variable names should not start with underscore _ or dollar sign $ characters, even though both are allowed.
+  
+* Variable names should be short yet meaningful. The choice of a variable name should be mnemonic, self descriptive and semantical
+  designed to indicate its intention.
+  
+* One-character variable names should be avoided like i, j, k, m etc
+  
+* Variable name should be plural if that is a collections. for e.g **employees**, **leaves** represents a list.
+
+* Variables names should be declared as per their types 
+  * Map/KeyValue pair should be declared as *keyToValue* and *valueByKey*. For e.g **ageByName** or  **nameToAge**.
+  * Set can be prefixed as *unique* before variable names. For e.g **uniqueNames**
+
+* Instance variable should be camelCase of their class names.
+  * employeeService is an instance of EmployeeService.
+  * reportDao is an instance of ReportDao.
+
+## Constants
+
+* Constants names holds same conventions as variable except it should be **UPPER_CASE** separated by **(_)** underscore.
+  * **AGE_BY_NAME**, **EMPLOYEE_REPORT**

docs/java/variables.md

@@ -26,12 +26,10 @@ module.exports =
         "label": "Naming Convention",
         "items": [
           "java/packages",
-          "java/files",
           "java/classes",
           "java/interfaces",
           "java/variables",
           "java/functions"
-          
         ]
       }
     ],