Showing 517 of 532 total issues
Define a constant instead of duplicating this literal "MainMenuAdapter" 3 times. Open
LogHelper.i("MainMenuAdapter", "Clicked on " + link);
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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.
Refactor this method to reduce its Cognitive Complexity from 20 to the 15 allowed. Open
private static String getBuildPropProperty(String key, @Nullable String trueString) {
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Cognitive Complexity is a measure of how hard the control flow of a method is to understand. Methods with high Cognitive Complexity will be difficult to maintain.
See
Refactor this method to reduce its Cognitive Complexity from 16 to the 15 allowed. Open
protected void onCreate(Bundle savedInstanceState) {
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Cognitive Complexity is a measure of how hard the control flow of a method is to understand. Methods with high Cognitive Complexity will be difficult to maintain.
See
Define a constant instead of duplicating this literal " seconds" 5 times. Open
new AlertDialog.Builder(this).setTitle("X Won!").setMessage("X has won the game!\nTime Taken: " + timerDuration + " seconds")
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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.
Merge this if statement with the enclosing one. Open
if (counterThread.isAlive()) {
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Merging collapsible if
statements increases the code's readability.
Noncompliant Code Example
if (file != null) { if (file.isFile() || file.isDirectory()) { /* ... */ } }
Compliant Solution
if (file != null && isFileOrDirectory(file)) { /* ... */ } private static boolean isFileOrDirectory(File file) { return file.isFile() || file.isDirectory(); }
Make the enclosing method "static" or remove this set. Open
currentPlayer = TicTacToeValues.X;
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Correctly updating a static
field from a non-static method is tricky to get right and could easily lead to bugs if there are multiple
class instances and/or multiple threads in play. Ideally, static
fields are only updated from synchronized static
methods.
This rule raises an issue each time a static
field is updated from a non-static method.
Noncompliant Code Example
public class MyClass { private static int count = 0; public void doSomething() { //... count++; // Noncompliant } }
Define a constant instead of duplicating this literal "java.vm.version" 3 times. Open
if (System.getProperty("java.vm.version").equals("2.1.0") && System.getProperty("java.vm.name").equals("Dalvik")) {
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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.
Make the enclosing method "static" or remove this set. Open
sharedPreferences = new AppPreferences(getApplicationContext());
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Correctly updating a static
field from a non-static method is tricky to get right and could easily lead to bugs if there are multiple
class instances and/or multiple threads in play. Ideally, static
fields are only updated from synchronized static
methods.
This rule raises an issue each time a static
field is updated from a non-static method.
Noncompliant Code Example
public class MyClass { private static int count = 0; public void doSomething() { //... count++; // Noncompliant } }
Add a private constructor to hide the implicit public one. Open
class ComputerAI {
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Utility classes, which are collections of static
members, are not meant to be instantiated. Even abstract utility classes, which can
be extended, should not have public constructors.
Java adds an implicit public constructor to every class which does not define at least one explicitly. Hence, at least one non-public constructor should be defined.
Noncompliant Code Example
class StringUtils { // Noncompliant public static String concatenate(String s1, String s2) { return s1 + s2; } }
Compliant Solution
class StringUtils { // Compliant private StringUtils() { throw new IllegalStateException("Utility class"); } public static String concatenate(String s1, String s2) { return s1 + s2; } }
Exceptions
When class contains public static void main(String[] args)
method it is not considered as utility class and will be ignored by this
rule.
Make the enclosing method "static" or remove this set. Open
turnNo++;
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Correctly updating a static
field from a non-static method is tricky to get right and could easily lead to bugs if there are multiple
class instances and/or multiple threads in play. Ideally, static
fields are only updated from synchronized static
methods.
This rule raises an issue each time a static
field is updated from a non-static method.
Noncompliant Code Example
public class MyClass { private static int count = 0; public void doSomething() { //... count++; // Noncompliant } }
This block of commented-out lines of code should be removed. Open
osCodename.setText(getString(R.string.sys_info_codename, getCodename(VERSION.SDK_INT)));// String.valueOf(Codenames.getCodename())));
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Programmers should not comment out code as it bloats programs and reduces readability.
Unused code should be deleted and can be retrieved from source control history if required.
This block of commented-out lines of code should be removed. Open
// tryRemovingNavView();
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Programmers should not comment out code as it bloats programs and reduces readability.
Unused code should be deleted and can be retrieved from source control history if required.
Save and re-use this "Random". Open
Random random = new Random();
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Creating a new Random
object each time a random value is needed is inefficient and may produce numbers which are not random depending
on the JDK. For better efficiency and randomness, create a single Random
, then store, and reuse it.
The Random()
constructor tries to set the seed with a distinct value every time. However there is no guarantee that the seed will be
random or even uniformly distributed. Some JDK will use the current time as seed, which makes the generated numbers not random at all.
This rule finds cases where a new Random
is created each time a method is invoked and assigned to a local random variable.
Noncompliant Code Example
public void doSomethingCommon() { Random rand = new Random(); // Noncompliant; new instance created with each invocation int rValue = rand.nextInt(); //...
Compliant Solution
private Random rand = SecureRandom.getInstanceStrong(); // SecureRandom is preferred to Random public void doSomethingCommon() { int rValue = this.rand.nextInt(); //...
Exceptions
A class which uses a Random
in its constructor or in a static main
function and nowhere else will be ignored by this
rule.
See
- OWASP Top 10 2017 Category A6 - Security Misconfiguration
Add a private constructor to hide the implicit public one. Open
class AlgorithmCheck {
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Utility classes, which are collections of static
members, are not meant to be instantiated. Even abstract utility classes, which can
be extended, should not have public constructors.
Java adds an implicit public constructor to every class which does not define at least one explicitly. Hence, at least one non-public constructor should be defined.
Noncompliant Code Example
class StringUtils { // Noncompliant public static String concatenate(String s1, String s2) { return s1 + s2; } }
Compliant Solution
class StringUtils { // Compliant private StringUtils() { throw new IllegalStateException("Utility class"); } public static String concatenate(String s1, String s2) { return s1 + s2; } }
Exceptions
When class contains public static void main(String[] args)
method it is not considered as utility class and will be ignored by this
rule.
Make the enclosing method "static" or remove this set. Open
gameStart = 2;
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Correctly updating a static
field from a non-static method is tricky to get right and could easily lead to bugs if there are multiple
class instances and/or multiple threads in play. Ideally, static
fields are only updated from synchronized static
methods.
This rule raises an issue each time a static
field is updated from a non-static method.
Noncompliant Code Example
public class MyClass { private static int count = 0; public void doSomething() { //... count++; // Noncompliant } }
Make the enclosing method "static" or remove this set. Open
currentPlayer = TicTacToeValues.O;
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Correctly updating a static
field from a non-static method is tricky to get right and could easily lead to bugs if there are multiple
class instances and/or multiple threads in play. Ideally, static
fields are only updated from synchronized static
methods.
This rule raises an issue each time a static
field is updated from a non-static method.
Noncompliant Code Example
public class MyClass { private static int count = 0; public void doSomething() { //... count++; // Noncompliant } }
Provide the parametrized type for this generic. Open
Class classObj = Class.forName(className);
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Generic types shouldn't be used raw (without type parameters) in variable declarations or return values. Doing so bypasses generic type checking, and defers the catch of unsafe code to runtime.
Noncompliant Code Example
List myList; // Noncompliant Set mySet; // Noncompliant
Compliant Solution
List<String> myList; Set<? extends Number> mySet;