itachi1706/CheesecakeUtilities

            switch (type) {

Close

The requirement for a final default clause is defensive programming. The clause should either take appropriate action, or contain a suitable comment as to why no action is taken.

Noncompliant Code Example

switch (param) {  //missing default clause
  case 0:
    doSomething();
    break;
  case 1:
    doSomethingElse();
    break;
}

switch (param) {
  default: // default clause should be the last one
    error();
    break;
  case 0:
    doSomething();
    break;
  case 1:
    doSomethingElse();
    break;
}

Compliant Solution

switch (param) {
  case 0:
    doSomething();
    break;
  case 1:
    doSomethingElse();
    break;
  default:
    error();
    break;
}

Exceptions

If the switch parameter is an Enum and if all the constants of this enum are used in the case statements, then no default clause is expected.

Example:

public enum Day {
    SUNDAY, MONDAY
}
...
switch(day) {
  case SUNDAY:
    doSomething();
    break;
  case MONDAY:
    doSomethingElse();
    break;
}

See

• MITRE, CWE-478 - Missing Default Case in Switch Statement
• CERT, MSC01-C. - Strive for logical completeness

public class BackupHelper {

Close

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.

            LogHelper.e("ListAppDetail", "Invalid Package Name. Exiting...");

Close

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.

            TelephonyManager tManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);

Close

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.

        return "Cannot Calculate";

Close

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.

        Random random = new Random();

Close

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

                            i += 3;

Close

A for loop stop condition should test the loop counter against an invariant value (i.e. one that is true at both the beginning and ending of every loop iteration). Ideally, this means that the stop condition is set to a local variable just before the loop begins.

Stop conditions that are not invariant are slightly less efficient, as well as being difficult to understand and maintain, and likely lead to the introduction of errors in the future.

This rule tracks three types of non-invariant stop conditions:

• When the loop counters are updated in the body of the for loop
• When the stop condition depend upon a method call
• When the stop condition depends on an object property, since such properties could change during the execution of the loop.

Noncompliant Code Example

for (int i = 0; i < 10; i++) {
  ...
  i = i - 1; // Noncompliant; counter updated in the body of the loop
  ...
}

Compliant Solution

for (int i = 0; i < 10; i++) {...}

                    .append(JsonHelper.getPushUpScore(pu, ageGroup, exercisesScore)).append(" pts)");

Close

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.

            message += "Mileage From: " + Companion.parseData(r.getMileageFrom(), decimal) + " km\n";

Close

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.

            recordsViewHolder.vehicle.setText("Unknown Vehicle");

Close

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.

            return "Free RAM: unknown";

Close

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.

            freq = new RandomAccessFile("/sys/devices/platform/gpusysfs/gpu_max_clock", "r").readLine();

Close

Connections, streams, files, and other classes that implement the Closeable interface or its super-interface, AutoCloseable, needs to be closed after use. Further, that close call must be made in a finally block otherwise an exception could keep the call from being made. Preferably, when class implements AutoCloseable, resource should be created using "try-with-resources" pattern and will be closed automatically.

Failure to properly close resources will result in a resource leak which could bring first the application and then perhaps the box the application is on to their knees.

Noncompliant Code Example

private void readTheFile() throws IOException {
  Path path = Paths.get(this.fileName);
  BufferedReader reader = Files.newBufferedReader(path, this.charset);
  // ...
  reader.close();  // Noncompliant
  // ...
  Files.lines("input.txt").forEach(System.out::println); // Noncompliant: The stream needs to be closed
}

private void doSomething() {
  OutputStream stream = null;
  try {
    for (String property : propertyList) {
      stream = new FileOutputStream("myfile.txt");  // Noncompliant
      // ...
    }
  } catch (Exception e) {
    // ...
  } finally {
    stream.close();  // Multiple streams were opened. Only the last is closed.
  }
}

Compliant Solution

private void readTheFile(String fileName) throws IOException {
    Path path = Paths.get(fileName);
    try (BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
      reader.readLine();
      // ...
    }
    // ..
    try (Stream<String> input = Files.lines("input.txt"))  {
      input.forEach(System.out::println);
    }
}

private void doSomething() {
  OutputStream stream = null;
  try {
    stream = new FileOutputStream("myfile.txt");
    for (String property : propertyList) {
      // ...
    }
  } catch (Exception e) {
    // ...
  } finally {
    stream.close();
  }
}

Exceptions

Instances of the following classes are ignored by this rule because close has no effect:

• java.io.ByteArrayOutputStream
• java.io.ByteArrayInputStream
• java.io.CharArrayReader
• java.io.CharArrayWriter
• java.io.StringReader
• java.io.StringWriter

Java 7 introduced the try-with-resources statement, which implicitly closes Closeables. All resources opened in a try-with-resources statement are ignored by this rule.

try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
  //...
}
catch ( ... ) {
  //...
}

See

• MITRE, CWE-459 - Incomplete Cleanup
• MITRE, CWE-772 - Missing Release of Resource after Effective Lifetime
• CERT, FIO04-J. - Release resources when they are no longer needed
• CERT, FIO42-C. - Close files when they are no longer needed
• Try With Resources

            load = new RandomAccessFile("/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq", "r").readLine();

Close

Connections, streams, files, and other classes that implement the Closeable interface or its super-interface, AutoCloseable, needs to be closed after use. Further, that close call must be made in a finally block otherwise an exception could keep the call from being made. Preferably, when class implements AutoCloseable, resource should be created using "try-with-resources" pattern and will be closed automatically.

Failure to properly close resources will result in a resource leak which could bring first the application and then perhaps the box the application is on to their knees.

Noncompliant Code Example

private void readTheFile() throws IOException {
  Path path = Paths.get(this.fileName);
  BufferedReader reader = Files.newBufferedReader(path, this.charset);
  // ...
  reader.close();  // Noncompliant
  // ...
  Files.lines("input.txt").forEach(System.out::println); // Noncompliant: The stream needs to be closed
}

private void doSomething() {
  OutputStream stream = null;
  try {
    for (String property : propertyList) {
      stream = new FileOutputStream("myfile.txt");  // Noncompliant
      // ...
    }
  } catch (Exception e) {
    // ...
  } finally {
    stream.close();  // Multiple streams were opened. Only the last is closed.
  }
}

Compliant Solution

private void readTheFile(String fileName) throws IOException {
    Path path = Paths.get(fileName);
    try (BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
      reader.readLine();
      // ...
    }
    // ..
    try (Stream<String> input = Files.lines("input.txt"))  {
      input.forEach(System.out::println);
    }
}

private void doSomething() {
  OutputStream stream = null;
  try {
    stream = new FileOutputStream("myfile.txt");
    for (String property : propertyList) {
      // ...
    }
  } catch (Exception e) {
    // ...
  } finally {
    stream.close();
  }
}

Exceptions

Instances of the following classes are ignored by this rule because close has no effect:

• java.io.ByteArrayOutputStream
• java.io.ByteArrayInputStream
• java.io.CharArrayReader
• java.io.CharArrayWriter
• java.io.StringReader
• java.io.StringWriter

Java 7 introduced the try-with-resources statement, which implicitly closes Closeables. All resources opened in a try-with-resources statement are ignored by this rule.

try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
  //...
}
catch ( ... ) {
  //...
}

See

• MITRE, CWE-459 - Incomplete Cleanup
• MITRE, CWE-772 - Missing Release of Resource after Effective Lifetime
• CERT, FIO04-J. - Release resources when they are no longer needed
• CERT, FIO42-C. - Close files when they are no longer needed
• Try With Resources

        return String.valueOf((long) Math.round((float) (Integer.parseInt(freq.replaceAll("[^\\d.]", "")) / 1000000))) + getString(R.string.sys_info_gpu_mhz);

Close

Certain math operations are just silly and should not be performed because their results are predictable.

In particular, anyValue % 1 is silly because it will always return 0.

Casting a non-floating-point value to floating-point and then passing it to Math.round, Math.ceil, or Math.floor is silly because the result will always be the original value.

These operations are silly with any constant value: Math.abs, Math.ceil, Math.floor, Math.rint, Math.round.

And these oprations are silly with certain constant values:

Operation	Value
acos	0.0 or 1.0
asin	0.0 or 1.0
atan	0.0 or 1.0
atan2	0.0
cbrt	0.0 or 1.0
cos	0.0
cosh	0.0
exp	0.0 or 1.0
expm1	0.0
log	0.0 or 1.0
log10	0.0 or 1.0
sin	0.0
sinh	0.0
sqrt	0.0 or 1.0
tan	0.0
tanh	0.0
toDegrees	0.0 or 1.0
toRadians	0.0

Noncompliant Code Example

public void doMath(int a) {
  double floor = Math.floor((double)a); // Noncompliant
  double ceiling = Math.ceil(4.2);  // Noncompliant
  double arcTan = Math.atan(0.0);  // Noncompliant
}

        } catch (SocketException ignored) {

Close

Most of the time a block of code is empty when a piece of code is really missing. So such empty block must be either filled or removed.

Noncompliant Code Example

for (int i = 0; i < 42; i++){}  // Empty on purpose or missing piece of code ?

Exceptions

When a block contains a comment, this block is not considered to be empty unless it is a synchronized block. synchronized blocks are still considered empty even with comments because they can still affect program flow.

        return String.valueOf((long) Math.round((float) Integer.parseInt(freq.replaceAll("[^\\d.]", "")))) + getString(R.string.sys_info_gpu_mhz);

Close

Certain math operations are just silly and should not be performed because their results are predictable.

In particular, anyValue % 1 is silly because it will always return 0.

Casting a non-floating-point value to floating-point and then passing it to Math.round, Math.ceil, or Math.floor is silly because the result will always be the original value.

These operations are silly with any constant value: Math.abs, Math.ceil, Math.floor, Math.rint, Math.round.

And these oprations are silly with certain constant values:

Operation	Value
acos	0.0 or 1.0
asin	0.0 or 1.0
atan	0.0 or 1.0
atan2	0.0
cbrt	0.0 or 1.0
cos	0.0
cosh	0.0
exp	0.0 or 1.0
expm1	0.0
log	0.0 or 1.0
log10	0.0 or 1.0
sin	0.0
sinh	0.0
sqrt	0.0 or 1.0
tan	0.0
tanh	0.0
toDegrees	0.0 or 1.0
toRadians	0.0

Noncompliant Code Example

public void doMath(int a) {
  double floor = Math.floor((double)a); // Noncompliant
  double ceiling = Math.ceil(4.2);  // Noncompliant
  double arcTan = Math.atan(0.0);  // Noncompliant
}

                    + "\nMountpoint: " + mem.getMountPoint() + "\nOptions: " + mem.getOptions();

Close

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.

            RandomAccessFile file = new RandomAccessFile("/proc/mounts", "r");

Close

Connections, streams, files, and other classes that implement the Closeable interface or its super-interface, AutoCloseable, needs to be closed after use. Further, that close call must be made in a finally block otherwise an exception could keep the call from being made. Preferably, when class implements AutoCloseable, resource should be created using "try-with-resources" pattern and will be closed automatically.

Failure to properly close resources will result in a resource leak which could bring first the application and then perhaps the box the application is on to their knees.

Noncompliant Code Example

private void readTheFile() throws IOException {
  Path path = Paths.get(this.fileName);
  BufferedReader reader = Files.newBufferedReader(path, this.charset);
  // ...
  reader.close();  // Noncompliant
  // ...
  Files.lines("input.txt").forEach(System.out::println); // Noncompliant: The stream needs to be closed
}

private void doSomething() {
  OutputStream stream = null;
  try {
    for (String property : propertyList) {
      stream = new FileOutputStream("myfile.txt");  // Noncompliant
      // ...
    }
  } catch (Exception e) {
    // ...
  } finally {
    stream.close();  // Multiple streams were opened. Only the last is closed.
  }
}

Compliant Solution

private void readTheFile(String fileName) throws IOException {
    Path path = Paths.get(fileName);
    try (BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
      reader.readLine();
      // ...
    }
    // ..
    try (Stream<String> input = Files.lines("input.txt"))  {
      input.forEach(System.out::println);
    }
}

private void doSomething() {
  OutputStream stream = null;
  try {
    stream = new FileOutputStream("myfile.txt");
    for (String property : propertyList) {
      // ...
    }
  } catch (Exception e) {
    // ...
  } finally {
    stream.close();
  }
}

Exceptions

Instances of the following classes are ignored by this rule because close has no effect:

• java.io.ByteArrayOutputStream
• java.io.ByteArrayInputStream
• java.io.CharArrayReader
• java.io.CharArrayWriter
• java.io.StringReader
• java.io.StringWriter

Java 7 introduced the try-with-resources statement, which implicitly closes Closeables. All resources opened in a try-with-resources statement are ignored by this rule.

try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
  //...
}
catch ( ... ) {
  //...
}

See

• MITRE, CWE-459 - Incomplete Cleanup
• MITRE, CWE-772 - Missing Release of Resource after Effective Lifetime
• CERT, FIO04-J. - Release resources when they are no longer needed
• CERT, FIO42-C. - Close files when they are no longer needed
• Try With Resources

        String path = "Path: " + Environment.getDataDirectory().getAbsolutePath();

Close

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.

            switch (msg.what) {

Close

The requirement for a final default clause is defensive programming. The clause should either take appropriate action, or contain a suitable comment as to why no action is taken.

Noncompliant Code Example

switch (param) {  //missing default clause
  case 0:
    doSomething();
    break;
  case 1:
    doSomethingElse();
    break;
}

switch (param) {
  default: // default clause should be the last one
    error();
    break;
  case 0:
    doSomething();
    break;
  case 1:
    doSomethingElse();
    break;
}

Compliant Solution

switch (param) {
  case 0:
    doSomething();
    break;
  case 1:
    doSomethingElse();
    break;
  default:
    error();
    break;
}

Exceptions

If the switch parameter is an Enum and if all the constants of this enum are used in the case statements, then no default clause is expected.

Example:

public enum Day {
    SUNDAY, MONDAY
}
...
switch(day) {
  case SUNDAY:
    doSomething();
    break;
  case MONDAY:
    doSomethingElse();
    break;
}

See

• MITRE, CWE-478 - Missing Default Case in Switch Statement
• CERT, MSC01-C. - Strive for logical completeness