Simple Clean Code Tips

Java Clean code Tips

Small Functions

Wrong

void processOrder(Order order) {
   // code to validate order
   // code
}

Right

void validateOrder(Order order) {...}
void processPayment(Order order) {...}

Minimize Dependencies

Wrong

class UserService{
   UserRepository userRepository = new
   UserRepository();
}

Right

class UserService {
   UserRepository _userRepository;
   UserService(UserRepository ur) {
   _userRepository
   }
}

Readability

Wrong

int i = 0;
for (int j = 0; j < 10; j++)
  i+=j;

Right

int sum = 0:
for (int num = 0; num < 10; num++)
   sum += num;

Avoid Boolean Parameters

Wrong

void setUserStatus(boolean isActive) {
   if (isActive) ... else ...
}

Right

void activateUser() {} 
void deactivateUser() {}

Error Handling

Wrong

try {
   // code
} catch (Exception e) {
   e.printStackTrace);
}

Right

try {
   // code
} catch (FileNotFoundException e) {
   // specific handling for file not found
} catch (10Exception e) {
   // specific handling for 10 issues
}

Consistent Formating

Wrong

public class Example{public void foo()(...}}

Right

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public class Example {
   public void foo(){...}
}

Comment Wisely

Wrong

// increment i by 1
i += 1;

Right

// Adjust index to account for 1-based array
index += 1;

Meaningful Names

Wrong

int d; // elapsed time in days

Right

int elapsedTimelnDays;

Single Responsibility

Wrong

class OrderManager {
   void processOrder(Order order) {... } 
   void saveOrder(Order order) {...}
}

Right

class OrderProcessor {
    void process(Order order) {...}
}
class OrderRepository {
    void save(Order order) {... }
}

Avoid Magic Numbers

Wrong

if (user.age > 65) {...}

Right

const int RETIREMENT_AGE = 65;
if (user.age > RETIREMENT_AGE) {...}
// Or you can define an enum and use it

Encapsulate Conditionals

Wrong

if (employee.age > RETIREMENT_AGE)
// ...

Right

if (employee.isEligibleForRetirement))
// ...

Use Exceptions, Not Error Codes

Wrong

if (user.isValid())
   // save user
   return 0; // success
}else {
   return -1; // error
}

Right

if (user.isValid() == false) {
    throw new InvalidUserException();
}