r4fterman/pdf.forms

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

public void run() {
  prepare("action1");                              // Noncompliant - "action1" is duplicated 3 times
  execute("action1");
  release("action1");
}

@SuppressWarning("all")                            // Compliant - annotations are excluded
private void method1() { /* ... */ }
@SuppressWarning("all")
private void method2() { /* ... */ }

public String method3(String a) {
  System.out.println("'" + a + "'");               // Compliant - literal "'" has less than 5 characters and is excluded
  return "";                                       // Compliant - literal "" has less than 5 characters and is excluded
}

Compliant Solution

private static final String ACTION_1 = "action1";  // Compliant

public void run() {
  prepare(ACTION_1);                               // Compliant
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

A dead store happens when a local variable is assigned a value that is not read by any subsequent instruction. Calculating or retrieving a value only to then overwrite it or throw it away, could indicate a serious error in the code. Even if it's not an error, it is at best a waste of resources. Therefore all calculated values should be used.

Noncompliant Code Example

i = a + b; // Noncompliant; calculation result not used before value is overwritten
i = compute();

Compliant Solution

i = a + b;
i += compute();

Exceptions

This rule ignores initializations to -1, 0, 1, null, true, false and "".

See

• MITRE, CWE-563 - Assignment to Variable without Use ('Unused Variable')
• CERT, MSC13-C. - Detect and remove unused values
• CERT, MSC56-J. - Detect and remove superfluous code and values

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 70.

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 70.

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 70.

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 70.

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 70.

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 54.

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 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 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 for long lines.

Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.

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 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 for long lines.

Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.

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

Checks that there are no import statements that use the * notation.

Rationale: Importing all classes from a package or staticmembers from a class leads to tight coupling between packagesor classes and might lead to problems when a new version of alibrary introduces name clashes.

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 for long lines.

Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.

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 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 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 that there are no import statements that use the * notation.

Rationale: Importing all classes from a package or staticmembers from a class leads to tight coupling between packagesor classes and might lead to problems when a new version of alibrary introduces name clashes.

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

Checks for long lines.

Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.

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 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 for long lines.

Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.

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