Adobe-Consulting-Services/acs-aem-commons

If a private field is declared but not used in the program, it can be considered dead code and should therefore be removed. This will improve maintainability because developers will not wonder what the variable is used for.

Note that this rule does not take reflection into account, which means that issues will be raised on private fields that are only accessed using the reflection API.

Noncompliant Code Example

public class MyClass {
  private int foo = 42;

  public int compute(int a) {
    return a * 42;
  }

}

Compliant Solution

public class MyClass {
  public int compute(int a) {
    return a * 42;
  }
}

Exceptions

The Java serialization runtime associates with each serializable class a version number, called serialVersionUID, which is used during deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatible with respect to serialization.

A serializable class can declare its own serialVersionUID explicitly by declaring a field named serialVersionUID that must be static, final, and of type long. By definition those serialVersionUID fields should not be reported by this rule:

public class MyClass implements java.io.Serializable {
  private static final long serialVersionUID = 42L;
}

Moreover, this rule doesn't raise any issue on annotated fields.

Checks the policy on how to wrap lines on operators.

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

Checks the header of a source file against a header that contains aregular expression for each line of the source header.

Rationale: In some projects checking against afixed header is not sufficient, e.g. the header might require acopyright line where the year information is not static.

For example, consider the following header:

Lines 1 and 6 demonstrate a more compact notation for 71 '/'characters. Line 4 enforces that the copyright notice includes afour digit year. Line 5 is an example how to enforce revisioncontrol keywords in a file header. Lines 12-14 is a template forjavadoc (line 13 is so complicated to remove conflict with and ofjavadoc comment). Lines 7, 9 and 11 will be treated as '^$' andwill forcefully expect the line to be empty.

Different programming languages have different comment syntaxrules, but all of them start a comment with a non-wordcharacter. Hence you can often use the non-word characterclass to abstract away the concrete comment syntax and allowchecking the header for different languages with a singleheader definition. For example, consider the following headerspecification (note that this is not the full Apache licenseheader):

Lines 1 and 2 leave room for technical header lines, e.g. the"#!/bin/sh" line in Unix shell scripts, or the XML file headerof XML files. Set the multiline property to "1, 2" so theselines can be ignored for file types where they do no apply.Lines 3 through 6 define the actual header content. Note howlines 2, 4 and 5 use escapes for characters that have specialregexp semantics.

In default configuration, if header is not specified, the default valueof header is set to null and the check does not rise any violations.

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

Checks the policy on how to wrap lines on operators.

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

Checks the policy on how to wrap lines on operators.

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

Checks the policy on how to wrap lines on operators.

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

Checks the policy on how to wrap lines on operators.

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