Define and throw a dedicated exception instead of using a generic one. Open
throw new RuntimeException(e);
- Read upRead up
- Exclude checks
Using such generic exceptions as Error
, RuntimeException
, Throwable
, and Exception
prevents
calling methods from handling true, system-generated exceptions differently than application-generated errors.
Noncompliant Code Example
public void foo(String bar) throws Throwable { // Noncompliant throw new RuntimeException("My Message"); // Noncompliant }
Compliant Solution
public void foo(String bar) { throw new MyOwnRuntimeException("My Message"); }
Exceptions
Generic exceptions in the signatures of overriding methods are ignored, because overriding method has to follow signature of the throw declaration in the superclass. The issue will be raised on superclass declaration of the method (or won't be raised at all if superclass is not part of the analysis).
@Override public void myMethod() throws Exception {...}
Generic exceptions are also ignored in the signatures of methods that make calls to methods that throw generic exceptions.
public void myOtherMethod throws Exception { doTheThing(); // this method throws Exception }
See
- MITRE, CWE-397 - Declaration of Throws for Generic Exception
- CERT, ERR07-J. - Do not throw RuntimeException, Exception, or Throwable
Define a constant instead of duplicating this literal "Not mocking" 4 times. Open
throw new IllegalStateException("Not mocking");
- Read upRead up
- Exclude checks
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.
This accessibility bypass should be removed. Open
server.set(null, null);
- Read upRead up
- Exclude checks
This rule raises an issue when reflection is used to change the visibility of a class, method or field, and when it is used to directly update a field value. Altering or bypassing the accessibility of classes, methods, or fields violates the encapsulation principle and could lead to run-time errors.
Noncompliant Code Example
public void makeItPublic(String methodName) throws NoSuchMethodException { this.getClass().getMethod(methodName).setAccessible(true); // Noncompliant } public void setItAnyway(String fieldName, int value) { this.getClass().getDeclaredField(fieldName).setInt(this, value); // Noncompliant; bypasses controls in setter }
See
- CERT, SEC05-J. - Do not use reflection to increase accessibility of classes, methods, or fields
Define and throw a dedicated exception instead of using a generic one. Open
throw new RuntimeException(e);
- Read upRead up
- Exclude checks
Using such generic exceptions as Error
, RuntimeException
, Throwable
, and Exception
prevents
calling methods from handling true, system-generated exceptions differently than application-generated errors.
Noncompliant Code Example
public void foo(String bar) throws Throwable { // Noncompliant throw new RuntimeException("My Message"); // Noncompliant }
Compliant Solution
public void foo(String bar) { throw new MyOwnRuntimeException("My Message"); }
Exceptions
Generic exceptions in the signatures of overriding methods are ignored, because overriding method has to follow signature of the throw declaration in the superclass. The issue will be raised on superclass declaration of the method (or won't be raised at all if superclass is not part of the analysis).
@Override public void myMethod() throws Exception {...}
Generic exceptions are also ignored in the signatures of methods that make calls to methods that throw generic exceptions.
public void myOtherMethod throws Exception { doTheThing(); // this method throws Exception }
See
- MITRE, CWE-397 - Declaration of Throws for Generic Exception
- CERT, ERR07-J. - Do not throw RuntimeException, Exception, or Throwable
This accessibility update should be removed. Open
server.setAccessible(true);
- Read upRead up
- Exclude checks
This rule raises an issue when reflection is used to change the visibility of a class, method or field, and when it is used to directly update a field value. Altering or bypassing the accessibility of classes, methods, or fields violates the encapsulation principle and could lead to run-time errors.
Noncompliant Code Example
public void makeItPublic(String methodName) throws NoSuchMethodException { this.getClass().getMethod(methodName).setAccessible(true); // Noncompliant } public void setItAnyway(String fieldName, int value) { this.getClass().getDeclaredField(fieldName).setInt(this, value); // Noncompliant; bypasses controls in setter }
See
- CERT, SEC05-J. - Do not use reflection to increase accessibility of classes, methods, or fields
Define and throw a dedicated exception instead of using a generic one. Open
throw new RuntimeException(e);
- Read upRead up
- Exclude checks
Using such generic exceptions as Error
, RuntimeException
, Throwable
, and Exception
prevents
calling methods from handling true, system-generated exceptions differently than application-generated errors.
Noncompliant Code Example
public void foo(String bar) throws Throwable { // Noncompliant throw new RuntimeException("My Message"); // Noncompliant }
Compliant Solution
public void foo(String bar) { throw new MyOwnRuntimeException("My Message"); }
Exceptions
Generic exceptions in the signatures of overriding methods are ignored, because overriding method has to follow signature of the throw declaration in the superclass. The issue will be raised on superclass declaration of the method (or won't be raised at all if superclass is not part of the analysis).
@Override public void myMethod() throws Exception {...}
Generic exceptions are also ignored in the signatures of methods that make calls to methods that throw generic exceptions.
public void myOtherMethod throws Exception { doTheThing(); // this method throws Exception }
See
- MITRE, CWE-397 - Declaration of Throws for Generic Exception
- CERT, ERR07-J. - Do not throw RuntimeException, Exception, or Throwable
Define and throw a dedicated exception instead of using a generic one. Open
throw new RuntimeException(e);
- Read upRead up
- Exclude checks
Using such generic exceptions as Error
, RuntimeException
, Throwable
, and Exception
prevents
calling methods from handling true, system-generated exceptions differently than application-generated errors.
Noncompliant Code Example
public void foo(String bar) throws Throwable { // Noncompliant throw new RuntimeException("My Message"); // Noncompliant }
Compliant Solution
public void foo(String bar) { throw new MyOwnRuntimeException("My Message"); }
Exceptions
Generic exceptions in the signatures of overriding methods are ignored, because overriding method has to follow signature of the throw declaration in the superclass. The issue will be raised on superclass declaration of the method (or won't be raised at all if superclass is not part of the analysis).
@Override public void myMethod() throws Exception {...}
Generic exceptions are also ignored in the signatures of methods that make calls to methods that throw generic exceptions.
public void myOtherMethod throws Exception { doTheThing(); // this method throws Exception }
See
- MITRE, CWE-397 - Declaration of Throws for Generic Exception
- CERT, ERR07-J. - Do not throw RuntimeException, Exception, or Throwable
Add the missing @deprecated Javadoc tag. Open
public static void unload()
- Read upRead up
- Exclude checks
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(); }
Remove this expression which always evaluates to "true" Open
if (mock != null && mock.getPluginManager() != null)
- Read upRead up
- Exclude checks
If a boolean expression doesn't change the evaluation of the condition, then it is entirely unnecessary, and can be removed. If it is gratuitous because it does not match the programmer's intent, then it's a bug and the expression should be fixed.
Noncompliant Code Example
a = true; if (a) { // Noncompliant doSomething(); } if (b && a) { // Noncompliant; "a" is always "true" doSomething(); } if (c || !a) { // Noncompliant; "!a" is always "false" doSomething(); }
Compliant Solution
a = true; if (foo(a)) { doSomething(); } if (b) { doSomething(); } if (c) { doSomething(); }
See
- MITRE, CWE-571 - Expression is Always True
- MITRE, CWE-570 - Expression is Always False
Identical blocks of code found in 2 locations. Consider refactoring. Open
if (mock != null)
{
JavaPlugin instance = mock.getPluginManager().loadPlugin(plugin, descriptionFile, parameters);
mock.getPluginManager().enablePlugin(instance);
return plugin.cast(instance);
- Read upRead up
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
Identical blocks of code found in 2 locations. Consider refactoring. Open
if (mock != null)
{
JavaPlugin instance = mock.getPluginManager().loadPlugin(plugin, description, parameters);
mock.getPluginManager().enablePlugin(instance);
return plugin.cast(instance);
- Read upRead up
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