[docs] Fix warnings about undocumented default constructors (#6151)

cscore/src/main/java/edu/wpi/first/cscore/VideoCamera.java

@@ -12,6 +12,9 @@ public static class WhiteBalance {
     public static final int kFixedOutdoor2 = 5000;
     public static final int kFixedFluorescent1 = 5100;
     public static final int kFixedFlourescent2 = 5200;
+
+    /** Default constructor. */
+    public WhiteBalance() {}
   }
 
   protected VideoCamera(int handle) {

hal/src/generate/FRCNetComm.java.in

@@ -9,7 +9,7 @@ package edu.wpi.first.hal;
 /**
  * JNI wrapper for library <b>FRC_NetworkCommunication</b><br>.
  */
-public class FRCNetComm {
+public final class FRCNetComm {
   /**
    * Resource type from UsageReporting.
    */
@@ -31,4 +31,7 @@ ${usage_reporting_types}
 
 ${usage_reporting_instances}
   }
+
+  /** Utility class. */
+  private FRCNetComm() {}
 }

hal/src/main/java/edu/wpi/first/hal/CANAPITypes.java

@@ -10,7 +10,8 @@
  * <p>This class defines enums for CAN device types and manufacturer IDs as specified in the WPILib
  * documentation: https://docs.wpilib.org/en/stable/docs/software/can-devices/can-addressing.html
  */
-public class CANAPITypes {
+@SuppressWarnings("PMD.MissingStaticMethodInNonInstantiatableClass")
+public final class CANAPITypes {
   /**
    * FRC CAN device type.
    *
@@ -80,4 +81,7 @@ public enum CANManufacturer {
       this.id = id;
     }
   }
+
+  /** Utility class. */
+  private CANAPITypes() {}
 }

hal/src/main/java/edu/wpi/first/hal/CANData.java

@@ -15,6 +15,9 @@ public class CANData {
   /** CAN frame timestamp in milliseconds. */
   public long timestamp;
 
+  /** Default constructor. */
+  public CANData() {}
+
   /**
    * API used from JNI to set the data.
    *

hal/src/main/java/edu/wpi/first/hal/CANStreamMessage.java

@@ -17,6 +17,9 @@ public class CANStreamMessage {
   @SuppressWarnings("MemberName")
   public int messageID;
 
+  /** Default constructor. */
+  public CANStreamMessage() {}
+
   /**
    * API used from JNI to set the data.
    *

hal/src/main/java/edu/wpi/first/hal/ControlWord.java

@@ -13,6 +13,9 @@ public class ControlWord {
   private boolean m_fmsAttached;
   private boolean m_dsAttached;
 
+  /** Default constructor. */
+  public ControlWord() {}
+
   void update(
       boolean enabled,
       boolean autonomous,

hal/src/main/java/edu/wpi/first/hal/DMAJNISample.java

@@ -26,6 +26,9 @@ static class BaseStore {
   private long m_timeStamp;
   private Map<Integer, BaseStore> m_propertyMap = new HashMap<>();
 
+  /** Default constructor. */
+  public DMAJNISample() {}
+
   public int update(int dmaHandle, double timeoutSeconds) {
     m_timeStamp = DMAJNI.readDMA(dmaHandle, timeoutSeconds, m_dataBuffer, m_storage);
     return m_storage[25];

hal/src/main/java/edu/wpi/first/hal/MatchInfoData.java

@@ -22,6 +22,9 @@ public class MatchInfoData {
   /** Stores the match type. */
   public int matchType;
 
+  /** Default constructor. */
+  public MatchInfoData() {}
+
   /**
    * Called from JNI to set the structure data.
    *

hal/src/main/java/edu/wpi/first/hal/can/CANJNI.java

@@ -23,6 +23,9 @@ public class CANJNI extends JNIWrapper {
   public static final int CAN_IS_FRAME_REMOTE = 0x80000000;
   public static final int CAN_IS_FRAME_11BIT = 0x40000000;
 
+  /** Default constructor. */
+  public CANJNI() {}
+
   /**
    * Sends a CAN message.
    *

hal/src/main/java/edu/wpi/first/hal/can/CANStatus.java

@@ -22,6 +22,9 @@ public class CANStatus {
   /** The CAN Bus transmit error count. */
   public int transmitErrorCount;
 
+  /** Default constructor. */
+  public CANStatus() {}
+
   /**
    * Set CAN bus status.
    *

hal/src/main/java/edu/wpi/first/hal/communication/NIRioStatus.java

@@ -12,4 +12,7 @@ public class NIRioStatus {
   public static final int kRIOStatusOperationTimedOut = -52007;
   public static final int kRIOStatusFeatureNotSupported = kRioStatusOffset - 193;
   public static final int kRIOStatusResourceNotInitialized = -52010;
+
+  /** Default constructor. */
+  public NIRioStatus() {}
 }

wpilibj/src/main/java/edu/wpi/first/wpilibj/DMASample.java

@@ -41,6 +41,9 @@ public static DMAReadStatus getValue(int value) {
 
   private final DMAJNISample m_dmaSample = new DMAJNISample();
 
+  /** Default constructor. */
+  public DMASample() {}
+
   public DMAReadStatus update(DMA dma, double timeoutSeconds) {
     return DMAReadStatus.getValue(m_dmaSample.update(dma.m_dmaHandle, timeoutSeconds));
   }

wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalSource.java

@@ -11,6 +11,9 @@
  * source. The source can either be a digital input or analog trigger but not both.
  */
 public abstract class DigitalSource implements AutoCloseable {
+  /** Default constructor. */
+  public DigitalSource() {}
+
   /**
    * Returns true if this DigitalSource is an AnalogTrigger.
    *

wpilibj/src/main/java/edu/wpi/first/wpilibj/event/EventLoop.java

@@ -15,6 +15,9 @@ public final class EventLoop {
   private final Collection<Runnable> m_bindings = new LinkedHashSet<>();
   private boolean m_running;
 
+  /** Default constructor. */
+  public EventLoop() {}
+
   /**
    * Bind a new action to run when the loop is polled.
    *

wpilibj/src/main/java/edu/wpi/first/wpilibj/smartdashboard/SendableBuilderImpl.java

@@ -109,6 +109,9 @@ void update(boolean controllable, long time) {
 
   private final List<AutoCloseable> m_closeables = new ArrayList<>();
 
+  /** Default constructor. */
+  public SendableBuilderImpl() {}
+
   @Override
   @SuppressWarnings("PMD.AvoidCatchingGenericException")
   public void close() {

wpiunits/src/main/java/edu/wpi/first/units/collections/LongToObjectHashMap.java

@@ -54,6 +54,9 @@ public class LongToObjectHashMap<V> {
   @SuppressWarnings("unchecked")
   private V[] m_values = (V[]) new Object[m_capacity];
 
+  /** Default constructor. */
+  public LongToObjectHashMap() {}
+
   /**
    * Puts a value {@code value} corresponding to key {@code key} in the map.
    *