r4fterman/pdf.forms

It's confusing to have a class member with the same name (case differences aside) as its enclosing class. This is particularly so when you consider the common practice of naming a class instance for the class itself.

Best practice dictates that any field or member with the same name as the enclosing class be renamed to be more descriptive of the particular aspect of the class it represents or holds.

Noncompliant Code Example

public class Foo {
  private String foo;

  public String getFoo() { }
}

Foo foo = new Foo();
foo.getFoo() // what does this return?

Compliant Solution

public class Foo {
  private String name;

  public String getName() { }
}

//...

Foo foo = new Foo();
foo.getName()

Exceptions

When the type of the field is the containing class and that field is static, no issue is raised to allow singletons named like the type.

public class Foo {
  ...
  private static Foo foo;
  public Foo getInstance() {
    if(foo==null) {
      foo = new Foo();
    }
    return foo;
  }
  ...
}

Overriding or shadowing a variable declared in an outer scope can strongly impact the readability, and therefore the maintainability, of a piece of code. Further, it could lead maintainers to introduce bugs because they think they're using one variable but are really using another.

Noncompliant Code Example

class Foo {
  public int myField;

  public void doSomething() {
    int myField = 0;
    ...
  }
}

See

• CERT, DCL01-C. - Do not reuse variable names in subscopes
• CERT, DCL51-J. - Do not shadow or obscure identifiers in subscopes

Deprecation should be marked with both the @Deprecated annotation and @deprecated Javadoc tag. The annotation enables tools such as IDEs to warn about referencing deprecated elements, and the tag can be used to explain when it was deprecated, why, and how references should be refactored.

Further, Java 9 adds two additional arguments to the annotation:

• since allows you to describe when the deprecation took place
• forRemoval, indicates whether the deprecated element will be removed at some future date

If your compile level is Java 9 or higher, you should be using one or both of these arguments.

Noncompliant Code Example

class MyClass {

  @Deprecated
  public void foo1() {
  }

  /**
    * @deprecated
    */
  public void foo2() {    // Noncompliant
  }

}

Compliant Solution

class MyClass {

  /**
    * @deprecated (when, why, refactoring advice...)
    */
  @Deprecated
  public void foo1() {
  }

  /**
    * Java >= 9
    * @deprecated (when, why, refactoring advice...)
    */
  @Deprecated(since="5.1")
  public void foo2() {
  }

  /**
    * Java >= 9
    * @deprecated (when, why, refactoring advice...)
    */
  @Deprecated(since="4.2", forRemoval=true)
  public void foo3() {
  }

}

Exceptions

The members and methods of a deprecated class or interface are ignored by this rule. The classes and interfaces themselves are still subject to it.

/**
 * @deprecated (when, why, etc...)
 */
@Deprecated
class Qix  {

  public void foo() {} // Compliant; class is deprecated

}

/**
 * @deprecated (when, why, etc...)
 */
@Deprecated
interface Plop {

  void bar();

}

Duplicated Code

Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

Tuning

This issue has a mass of 50.

We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

Refactorings

• Extract Method
• Extract Class
• Form Template Method
• Introduce Null Object
• Pull Up Method
• Pull Up Field
• Substitute Algorithm

Further Reading

• Don't Repeat Yourself on the C2 Wiki
• Duplicated Code on SourceMaking
• Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76

Duplicated Code

Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

Tuning

This issue has a mass of 45.

We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

Refactorings

• Extract Method
• Extract Class
• Form Template Method
• Introduce Null Object
• Pull Up Method
• Pull Up Field
• Substitute Algorithm

Further Reading

• Don't Repeat Yourself on the C2 Wiki
• Duplicated Code on SourceMaking
• Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76

Checks that method parameter names conform to a specified pattern.By using accessModifiers property it is possibleto specify different formats for methods at different visibility levels.

To validate catch parameters please useCatchParameterName.

To validate lambda parameters please useLambdaParameterName.

This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.

Checks thatJavadoc summary sentence does not contain phrases that are not recommended to use.Summaries that contain only the {@inheritDoc} tag are skipped. Check alsoviolate Javadoc that does not contain first sentence.

This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.

Checks that the groups of import declarations appear in the order specifiedby the user. If there is an import but its group is not specified in theconfiguration such an import should be placed at the end of the import list.

This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.

Checks that the groups of import declarations appear in the order specifiedby the user. If there is an import but its group is not specified in theconfiguration such an import should be placed at the end of the import list.

This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.

Checks thatJavadoc summary sentence does not contain phrases that are not recommended to use.Summaries that contain only the {@inheritDoc} tag are skipped. Check alsoviolate Javadoc that does not contain first sentence.

This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.

Checks that the groups of import declarations appear in the order specifiedby the user. If there is an import but its group is not specified in theconfiguration such an import should be placed at the end of the import list.

This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.