SiLeBAT/FSK-Lab

        success = MainKernel.sendRequest("GRANT " + MainKernel.delimitL("DBA") + " TO " + MainKernel.delimitL(username), false);

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.

                triggerFired = System.currentTimeMillis();

Close

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
  }
}

                if (DBKernel.mainFrame.isVisible() && DBKernel.mainFrame.getExtendedState() == JFrame.MAXIMIZED_BOTH) {

Close

In the interest of code clarity, static members of a base class should never be accessed using a derived type's name. Doing so is confusing and could create the illusion that two different static members exist.

Noncompliant Code Example

class Parent {
  public static int counter;
}

class Child extends Parent {
  public Child() {
    Child.counter++;  // Noncompliant
  }
}

Compliant Solution

class Parent {
  public static int counter;
}

class Child extends Parent {
  public Child() {
    Parent.counter++;
  }
}

            System.gc();

Close

Calling System.gc() or Runtime.getRuntime().gc() is a bad idea for a simple reason: there is no way to know exactly what will be done under the hood by the JVM because the behavior will depend on its vendor, version and options:

• Will the whole application be frozen during the call?
• Is the -XX:DisableExplicitGC option activated?
• Will the JVM simply ignore the call?
• ...

Like for System.gc(), there is no reason to manually call runFinalization() to force the call of finalization methods of any objects pending finalization.

An application relying on these unpredictable methods is also unpredictable and therefore broken. The task of running the garbage collector and calling finalize() methods should be left exclusively to the JVM.

                            sql = "INSERT INTO " + DBKernel.delimitL("Prozessdaten") +

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.

        private int getReihenfolgePrev(Vector<Integer[]> org_dst, Vector<Integer> indexReihenfolge) {

Close

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

• Cognitive Complexity

                        if (sql != null) sql += " AND " + DBKernel.delimitL(fn[i-1]) + " IS NULL";

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.

    private static boolean doRestore(String path, final MyDBTable myDB, final File targzFile, final boolean silent, boolean doReconnect) {

Close

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

• Cognitive Complexity

            System.gc();

Close

Calling System.gc() or Runtime.getRuntime().gc() is a bad idea for a simple reason: there is no way to know exactly what will be done under the hood by the JVM because the behavior will depend on its vendor, version and options:

• Will the whole application be frozen during the call?
• Is the -XX:DisableExplicitGC option activated?
• Will the JVM simply ignore the call?
• ...

Like for System.gc(), there is no reason to manually call runFinalization() to force the call of finalization methods of any objects pending finalization.

An application relying on these unpredictable methods is also unpredictable and therefore broken. The task of running the garbage collector and calling finalize() methods should be left exclusively to the JVM.

        ResultSet rs = getResultSet(conn, "SELECT " + delimitL("Wert") + " FROM " + delimitL("Infotabelle") + " WHERE " + delimitL("Parameter") + " = 'lastCache_" + tablename

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.

    final static String HSH_PATH = System.getProperty("user.home") + System.getProperty("file.separator") + ".localHSH" + System.getProperty("file.separator") + "BfR"

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.

            String sql = "SELECT " + DBKernel.delimitL("Parameter") + " FROM " + DBKernel.delimitL("SonstigeParameter");

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.

        sql += DBKernel.delimitL("Table") + "=" + "'" + tablename + "' AND";

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.

        String sql = "SELECT " + DBKernel.delimitL("TableID") + "," + DBKernel.delimitL("SourceID") + " FROM " + DBKernel.delimitL("DataSource") + " WHERE ";

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.

                String sql = "INSERT INTO " + delimitL("DateiSpeicher") + " (" + delimitL("Zeitstempel") + "," + delimitL("Tabelle") + "," + delimitL("Feld") + ","

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.

        try {

Close

Java 7 introduced the try-with-resources statement, which guarantees that the resource in question will be closed. Since the new syntax is closer to bullet-proof, it should be preferred over the older try/catch/finally version.

This rule checks that close-able resources are opened in a try-with-resources statement.

Note that this rule is automatically disabled when the project's sonar.java.source is lower than 7.

Noncompliant Code Example

FileReader fr = null;
BufferedReader br = null;
try {
  fr = new FileReader(fileName);
  br = new BufferedReader(fr);
  return br.readLine();
} catch (...) {
} finally {
  if (br != null) {
    try {
      br.close();
    } catch(IOException e){...}
  }
  if (fr != null ) {
    try {
      br.close();
    } catch(IOException e){...}
  }
}

Compliant Solution

try (
    FileReader fr = new FileReader(fileName);
    BufferedReader br = new BufferedReader(fr)
  ) {
  return br.readLine();
}
catch (...) {}

or

try (BufferedReader br =
        new BufferedReader(new FileReader(fileName))) { // no need to name intermediate resources if you don't want to
  return br.readLine();
}
catch (...) {}

See

• CERT, ERR54-J. - Use a try-with-resources statement to safely handle closeable resources

    private boolean different(final Object[] rowBefore,

Close

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

• Cognitive Complexity

    public static boolean dbBackup(final JFrame frame) {

Close

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

• Cognitive Complexity

    private static void dbBackup(final JFrame frame, final File backupFile, final boolean silent) {

Close

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

• Cognitive Complexity

            Statement anfrage = getDBConnection().createStatement();

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