use checkPositive/checkPositiveOrZero (#8803)

Motivation:

We have a utility method to check for > 0 and >0 arguments. We should use it.

Modification:

use checkPositive/checkPositiveOrZero instead of if statement.

Result:

Re-use utility method.

buffer/src/main/java/io/netty/buffer/AbstractByteBuf.java

@@ -38,6 +38,7 @@ import java.nio.channels.ScatteringByteChannel;
 import java.nio.charset.Charset;
 
 import static io.netty.util.internal.MathUtil.isOutOfBounds;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 /**
  * A skeletal implementation of a buffer.
@@ -73,9 +74,7 @@ public abstract class AbstractByteBuf extends ByteBuf {
     private int maxCapacity;
 
     protected AbstractByteBuf(int maxCapacity) {
-        if (maxCapacity < 0) {
+        checkPositiveOrZero(maxCapacity, "maxCapacity");
-            throw new IllegalArgumentException("maxCapacity: " + maxCapacity + " (expected: >= 0)");
-        }
         this.maxCapacity = maxCapacity;
     }
 
@@ -271,10 +270,7 @@ public abstract class AbstractByteBuf extends ByteBuf {
 
     @Override
     public ByteBuf ensureWritable(int minWritableBytes) {
-        if (minWritableBytes < 0) {
+        checkPositiveOrZero(minWritableBytes, "minWritableBytes");
-            throw new IllegalArgumentException(String.format(
-                    "minWritableBytes: %d (expected: >= 0)", minWritableBytes));
-        }
         ensureWritable0(minWritableBytes);
         return this;
     }
@@ -302,10 +298,7 @@ public abstract class AbstractByteBuf extends ByteBuf {
     @Override
     public int ensureWritable(int minWritableBytes, boolean force) {
         ensureAccessible();
-        if (minWritableBytes < 0) {
+        checkPositiveOrZero(minWritableBytes, "minWritableBytes");
-            throw new IllegalArgumentException(String.format(
-                    "minWritableBytes: %d (expected: >= 0)", minWritableBytes));
-        }
 
         if (minWritableBytes <= writableBytes()) {
             return 0;
@@ -1414,9 +1407,7 @@ public abstract class AbstractByteBuf extends ByteBuf {
      * than the specified value.
      */
     protected final void checkReadableBytes(int minimumReadableBytes) {
-        if (minimumReadableBytes < 0) {
+        checkPositiveOrZero(minimumReadableBytes, "minimumReadableBytes");
-            throw new IllegalArgumentException("minimumReadableBytes: " + minimumReadableBytes + " (expected: >= 0)");
-        }
         checkReadableBytes0(minimumReadableBytes);
     }
 

buffer/src/main/java/io/netty/buffer/AbstractByteBufAllocator.java

@@ -16,6 +16,8 @@
 
 package io.netty.buffer;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.util.ResourceLeakDetector;
 import io.netty.util.ResourceLeakTracker;
 import io.netty.util.internal.PlatformDependent;
@@ -222,9 +224,7 @@ public abstract class AbstractByteBufAllocator implements ByteBufAllocator {
     }
 
     private static void validate(int initialCapacity, int maxCapacity) {
-        if (initialCapacity < 0) {
+        checkPositiveOrZero(initialCapacity, "initialCapacity");
-            throw new IllegalArgumentException("initialCapacity: " + initialCapacity + " (expected: 0+)");
-        }
         if (initialCapacity > maxCapacity) {
             throw new IllegalArgumentException(String.format(
                     "initialCapacity: %d (expected: not greater than maxCapacity(%d)",
@@ -249,9 +249,7 @@ public abstract class AbstractByteBufAllocator implements ByteBufAllocator {
 
     @Override
     public int calculateNewCapacity(int minNewCapacity, int maxCapacity) {
-        if (minNewCapacity < 0) {
+        checkPositiveOrZero(minNewCapacity, "minNewCapacity");
-            throw new IllegalArgumentException("minNewCapacity: " + minNewCapacity + " (expected: 0+)");
-        }
         if (minNewCapacity > maxCapacity) {
             throw new IllegalArgumentException(String.format(
                     "minNewCapacity: %d (expected: not greater than maxCapacity(%d)",

buffer/src/main/java/io/netty/buffer/ByteBufUtil.java

@@ -43,6 +43,7 @@ import java.util.Locale;
 
 import static io.netty.util.internal.MathUtil.isOutOfBounds;
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 import static io.netty.util.internal.StringUtil.NEWLINE;
 import static io.netty.util.internal.StringUtil.isSurrogate;
 
@@ -1000,9 +1001,7 @@ public final class ByteBufUtil {
         }
 
         private static String hexDump(ByteBuf buffer, int fromIndex, int length) {
-            if (length < 0) {
+            checkPositiveOrZero(length, "length");
-              throw new IllegalArgumentException("length: " + length);
-            }
             if (length == 0) {
               return "";
             }
@@ -1022,9 +1021,7 @@ public final class ByteBufUtil {
         }
 
         private static String hexDump(byte[] array, int fromIndex, int length) {
-            if (length < 0) {
+            checkPositiveOrZero(length, "length");
-              throw new IllegalArgumentException("length: " + length);
-            }
             if (length == 0) {
                 return "";
             }

buffer/src/main/java/io/netty/buffer/EmptyByteBuf.java

@@ -16,6 +16,8 @@
 
 package io.netty.buffer;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.util.ByteProcessor;
 import io.netty.util.internal.EmptyArrays;
 import io.netty.util.internal.PlatformDependent;
@@ -223,9 +225,7 @@ public final class EmptyByteBuf extends ByteBuf {
 
     @Override
     public ByteBuf ensureWritable(int minWritableBytes) {
-        if (minWritableBytes < 0) {
+        checkPositiveOrZero(minWritableBytes, "minWritableBytes");
-            throw new IllegalArgumentException("minWritableBytes: " + minWritableBytes + " (expected: >= 0)");
-        }
         if (minWritableBytes != 0) {
             throw new IndexOutOfBoundsException();
         }
@@ -234,9 +234,7 @@ public final class EmptyByteBuf extends ByteBuf {
 
     @Override
     public int ensureWritable(int minWritableBytes, boolean force) {
-        if (minWritableBytes < 0) {
+        checkPositiveOrZero(minWritableBytes, "minWritableBytes");
-            throw new IllegalArgumentException("minWritableBytes: " + minWritableBytes + " (expected: >= 0)");
-        }
 
         if (minWritableBytes == 0) {
             return 0;
@@ -1048,9 +1046,7 @@ public final class EmptyByteBuf extends ByteBuf {
     }
 
     private ByteBuf checkIndex(int index, int length) {
-        if (length < 0) {
+        checkPositiveOrZero(length, "length");
-            throw new IllegalArgumentException("length: " + length);
-        }
         if (index != 0 || length != 0) {
             throw new IndexOutOfBoundsException();
         }
@@ -1058,9 +1054,7 @@ public final class EmptyByteBuf extends ByteBuf {
     }
 
     private ByteBuf checkLength(int length) {
-        if (length < 0) {
+        checkPositiveOrZero(length, "length");
-            throw new IllegalArgumentException("length: " + length + " (expected: >= 0)");
-        }
         if (length != 0) {
             throw new IndexOutOfBoundsException();
         }

buffer/src/main/java/io/netty/buffer/PoolArena.java

@@ -26,6 +26,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 import static java.lang.Math.max;
 
 abstract class PoolArena<T> implements PoolArenaMetric {
@@ -330,9 +331,7 @@ abstract class PoolArena<T> implements PoolArenaMetric {
     }
 
     int normalizeCapacity(int reqCapacity) {
-        if (reqCapacity < 0) {
+        checkPositiveOrZero(reqCapacity, "reqCapacity");
-            throw new IllegalArgumentException("capacity: " + reqCapacity + " (expected: 0+)");
-        }
 
         if (reqCapacity >= chunkSize) {
             return directMemoryCacheAlignment == 0 ? reqCapacity : alignCapacity(reqCapacity);

buffer/src/main/java/io/netty/buffer/PoolThreadCache.java

@@ -17,6 +17,8 @@
 package io.netty.buffer;
 
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.buffer.PoolArena.SizeClass;
 import io.netty.util.Recycler;
 import io.netty.util.Recycler.Handle;
@@ -65,10 +67,7 @@ final class PoolThreadCache {
     PoolThreadCache(PoolArena<byte[]> heapArena, PoolArena<ByteBuffer> directArena,
                     int tinyCacheSize, int smallCacheSize, int normalCacheSize,
                     int maxCachedBufferCapacity, int freeSweepAllocationThreshold) {
-        if (maxCachedBufferCapacity < 0) {
+        checkPositiveOrZero(maxCachedBufferCapacity, "maxCachedBufferCapacity");
-            throw new IllegalArgumentException("maxCachedBufferCapacity: "
-                    + maxCachedBufferCapacity + " (expected: >= 0)");
-        }
         this.freeSweepAllocationThreshold = freeSweepAllocationThreshold;
         this.heapArena = heapArena;
         this.directArena = directArena;

buffer/src/main/java/io/netty/buffer/PooledByteBufAllocator.java

@@ -16,6 +16,8 @@
 
 package io.netty.buffer;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.util.NettyRuntime;
 import io.netty.util.concurrent.FastThreadLocal;
 import io.netty.util.concurrent.FastThreadLocalThread;
@@ -215,17 +217,10 @@ public class PooledByteBufAllocator extends AbstractByteBufAllocator implements
         this.normalCacheSize = normalCacheSize;
         chunkSize = validateAndCalculateChunkSize(pageSize, maxOrder);
 
-        if (nHeapArena < 0) {
+        checkPositiveOrZero(nHeapArena, "nHeapArena");
-            throw new IllegalArgumentException("nHeapArena: " + nHeapArena + " (expected: >= 0)");
+        checkPositiveOrZero(nDirectArena, "nDirectArena");
-        }
-        if (nDirectArena < 0) {
-            throw new IllegalArgumentException("nDirectArea: " + nDirectArena + " (expected: >= 0)");
-        }
 
-        if (directMemoryCacheAlignment < 0) {
+        checkPositiveOrZero(directMemoryCacheAlignment, "directMemoryCacheAlignment");
-            throw new IllegalArgumentException("directMemoryCacheAlignment: "
-                    + directMemoryCacheAlignment + " (expected: >= 0)");
-        }
         if (directMemoryCacheAlignment > 0 && !isDirectMemoryCacheAlignmentSupported()) {
             throw new IllegalArgumentException("directMemoryCacheAlignment is not supported");
         }

buffer/src/main/java/io/netty/buffer/UnpooledDirectByteBuf.java

@@ -15,6 +15,8 @@
  */
 package io.netty.buffer;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.util.internal.PlatformDependent;
 
 import java.io.IOException;
@@ -52,12 +54,8 @@ public class UnpooledDirectByteBuf extends AbstractReferenceCountedByteBuf {
         if (alloc == null) {
             throw new NullPointerException("alloc");
         }
-        if (initialCapacity < 0) {
+        checkPositiveOrZero(initialCapacity, "initialCapacity");
-            throw new IllegalArgumentException("initialCapacity: " + initialCapacity);
+        checkPositiveOrZero(maxCapacity, "maxCapacity");
-        }
-        if (maxCapacity < 0) {
-            throw new IllegalArgumentException("maxCapacity: " + maxCapacity);
-        }
         if (initialCapacity > maxCapacity) {
             throw new IllegalArgumentException(String.format(
                     "initialCapacity(%d) > maxCapacity(%d)", initialCapacity, maxCapacity));

buffer/src/main/java/io/netty/buffer/UnpooledUnsafeDirectByteBuf.java

@@ -15,6 +15,8 @@
  */
 package io.netty.buffer;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.util.internal.PlatformDependent;
 
 import java.io.IOException;
@@ -53,12 +55,8 @@ public class UnpooledUnsafeDirectByteBuf extends AbstractReferenceCountedByteBuf
         if (alloc == null) {
             throw new NullPointerException("alloc");
         }
-        if (initialCapacity < 0) {
+        checkPositiveOrZero(initialCapacity, "initialCapacity");
-            throw new IllegalArgumentException("initialCapacity: " + initialCapacity);
+        checkPositiveOrZero(maxCapacity, "maxCapacity");
-        }
-        if (maxCapacity < 0) {
-            throw new IllegalArgumentException("maxCapacity: " + maxCapacity);
-        }
         if (initialCapacity > maxCapacity) {
             throw new IllegalArgumentException(String.format(
                     "initialCapacity(%d) > maxCapacity(%d)", initialCapacity, maxCapacity));

codec/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java

@@ -15,6 +15,8 @@
  */
 package io.netty.handler.codec;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
 import io.netty.buffer.CompositeByteBuf;
@@ -202,9 +204,7 @@ public abstract class ByteToMessageDecoder extends ChannelInboundHandlerAdapter
      * The default is {@code 16}.
      */
     public void setDiscardAfterReads(int discardAfterReads) {
-        if (discardAfterReads <= 0) {
+        checkPositive(discardAfterReads, "discardAfterReads");
-            throw new IllegalArgumentException("discardAfterReads must be > 0");
-        }
         this.discardAfterReads = discardAfterReads;
     }
 

codec/src/main/java/io/netty/handler/codec/DelimiterBasedFrameDecoder.java

@@ -15,6 +15,8 @@
  */
 package io.netty.handler.codec;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 
@@ -346,10 +348,6 @@ public class DelimiterBasedFrameDecoder extends ByteToMessageDecoder {
     }
 
     private static void validateMaxFrameLength(int maxFrameLength) {
-        if (maxFrameLength <= 0) {
+        checkPositive(maxFrameLength, "maxFrameLength");
-            throw new IllegalArgumentException(
-                    "maxFrameLength must be a positive integer: " +
-                    maxFrameLength);
-        }
     }
 }

codec/src/main/java/io/netty/handler/codec/FixedLengthFrameDecoder.java

@@ -15,6 +15,8 @@
  */
 package io.netty.handler.codec;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 
@@ -46,10 +48,7 @@ public class FixedLengthFrameDecoder extends ByteToMessageDecoder {
      * @param frameLength the length of the frame
      */
     public FixedLengthFrameDecoder(int frameLength) {
-        if (frameLength <= 0) {
+        checkPositive(frameLength, "frameLength");
-            throw new IllegalArgumentException(
-                    "frameLength must be a positive integer: " + frameLength);
-        }
         this.frameLength = frameLength;
     }
 

codec/src/main/java/io/netty/handler/codec/LengthFieldBasedFrameDecoder.java

@@ -15,6 +15,9 @@
  */
 package io.netty.handler.codec;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import java.nio.ByteOrder;
 import java.util.List;
 
@@ -302,23 +305,11 @@ public class LengthFieldBasedFrameDecoder extends ByteToMessageDecoder {
             throw new NullPointerException("byteOrder");
         }
 
-        if (maxFrameLength <= 0) {
+        checkPositive(maxFrameLength, "maxFrameLength");
-            throw new IllegalArgumentException(
-                    "maxFrameLength must be a positive integer: " +
-                    maxFrameLength);
-        }
 
-        if (lengthFieldOffset < 0) {
+        checkPositiveOrZero(lengthFieldOffset, "lengthFieldOffset");
-            throw new IllegalArgumentException(
-                    "lengthFieldOffset must be a non-negative integer: " +
-                    lengthFieldOffset);
-        }
 
-        if (initialBytesToStrip < 0) {
+        checkPositiveOrZero(initialBytesToStrip, "initialBytesToStrip");
-            throw new IllegalArgumentException(
-                    "initialBytesToStrip must be a non-negative integer: " +
-                    initialBytesToStrip);
-        }
 
         if (lengthFieldOffset > maxFrameLength - lengthFieldLength) {
             throw new IllegalArgumentException(

codec/src/main/java/io/netty/handler/codec/LengthFieldPrepender.java

@@ -15,6 +15,8 @@
  */
 package io.netty.handler.codec;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandler.Sharable;
 import io.netty.channel.ChannelHandlerContext;
@@ -163,10 +165,7 @@ public class LengthFieldPrepender extends MessageToMessageEncoder<ByteBuf> {
             length += lengthFieldLength;
         }
 
-        if (length < 0) {
+        checkPositiveOrZero(length, "length");
-            throw new IllegalArgumentException(
-                    "Adjusted frame length (" + length + ") is less than zero");
-        }
 
         switch (lengthFieldLength) {
         case 1:

codec/src/main/java/io/netty/handler/codec/MessageAggregator.java

@@ -28,6 +28,7 @@ import io.netty.util.ReferenceCountUtil;
 import java.util.List;
 
 import static io.netty.buffer.Unpooled.EMPTY_BUFFER;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 /**
  * An abstract {@link ChannelHandler} that aggregates a series of message objects into a single aggregated message.
@@ -81,9 +82,7 @@ public abstract class MessageAggregator<I, S, C extends ByteBufHolder, O extends
     }
 
     private static void validateMaxContentLength(int maxContentLength) {
-        if (maxContentLength < 0) {
+        checkPositiveOrZero(maxContentLength, "maxContentLength");
-            throw new IllegalArgumentException("maxContentLength: " + maxContentLength + " (expected: >= 0)");
-        }
     }
 
     @Override

testsuite-http2/src/main/java/io/netty/testsuite/http2/Http2ServerInitializer.java

@@ -16,6 +16,8 @@
 
 package io.netty.testsuite.http2;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelInitializer;
@@ -59,9 +61,7 @@ public class Http2ServerInitializer extends ChannelInitializer<SocketChannel> {
     }
 
     Http2ServerInitializer(int maxHttpContentLength) {
-        if (maxHttpContentLength < 0) {
+        checkPositiveOrZero(maxHttpContentLength, "maxHttpContentLength");
-            throw new IllegalArgumentException("maxHttpContentLength (expected >= 0): " + maxHttpContentLength);
-        }
         this.maxHttpContentLength = maxHttpContentLength;
     }
 

transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollStreamChannel.java

@@ -54,6 +54,7 @@ import static io.netty.channel.internal.ChannelUtils.MAX_BYTES_PER_GATHERING_WRI
 import static io.netty.channel.internal.ChannelUtils.WRITE_STATUS_SNDBUF_FULL;
 import static io.netty.channel.unix.FileDescriptor.pipe;
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel implements DuplexChannel {
     private static final ChannelMetadata METADATA = new ChannelMetadata(false, 16);
@@ -163,9 +164,7 @@ public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel im
         if (ch.eventLoop() != eventLoop()) {
             throw new IllegalArgumentException("EventLoops are not the same.");
         }
-        if (len < 0) {
+        checkPositiveOrZero(len, "len");
-            throw new IllegalArgumentException("len: " + len + " (expected: >= 0)");
-        }
         if (ch.config().getEpollMode() != EpollMode.LEVEL_TRIGGERED
                 || config().getEpollMode() != EpollMode.LEVEL_TRIGGERED) {
             throw new IllegalStateException("spliceTo() supported only when using " + EpollMode.LEVEL_TRIGGERED);
@@ -214,12 +213,8 @@ public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel im
      */
     public final ChannelFuture spliceTo(final FileDescriptor ch, final int offset, final int len,
                                         final ChannelPromise promise) {
-        if (len < 0) {
+        checkPositiveOrZero(len, "len");
-            throw new IllegalArgumentException("len: " + len + " (expected: >= 0)");
+        checkPositiveOrZero(offset, "offser");
-        }
-        if (offset < 0) {
-            throw new IllegalArgumentException("offset must be >= 0 but was " + offset);
-        }
         if (config().getEpollMode() != EpollMode.LEVEL_TRIGGERED) {
             throw new IllegalStateException("spliceTo() supported only when using " + EpollMode.LEVEL_TRIGGERED);
         }

transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollServerChannelConfig.java

@@ -30,6 +30,7 @@ import java.util.Map;
 import static io.netty.channel.ChannelOption.SO_BACKLOG;
 import static io.netty.channel.ChannelOption.SO_RCVBUF;
 import static io.netty.channel.ChannelOption.SO_REUSEADDR;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 public class EpollServerChannelConfig extends EpollChannelConfig implements ServerSocketChannelConfig {
     private volatile int backlog = NetUtil.SOMAXCONN;
@@ -120,9 +121,7 @@ public class EpollServerChannelConfig extends EpollChannelConfig implements Serv
     }
 
     public EpollServerChannelConfig setBacklog(int backlog) {
-        if (backlog < 0) {
+        checkPositiveOrZero(backlog, "backlog");
-            throw new IllegalArgumentException("backlog: " + backlog);
-        }
         this.backlog = backlog;
         return this;
     }
@@ -146,9 +145,7 @@ public class EpollServerChannelConfig extends EpollChannelConfig implements Serv
      * @see <a href="https://tools.ietf.org/html/rfc7413">RFC 7413 TCP FastOpen</a>
      */
     public EpollServerChannelConfig setTcpFastopen(int pendingFastOpenRequestsThreshold) {
-        if (this.pendingFastOpenRequestsThreshold < 0) {
+        checkPositiveOrZero(this.pendingFastOpenRequestsThreshold, "pendingFastOpenRequestsThreshold");
-            throw new IllegalArgumentException("pendingFastOpenRequestsThreshold: " + pendingFastOpenRequestsThreshold);
-        }
         this.pendingFastOpenRequestsThreshold = pendingFastOpenRequestsThreshold;
         return this;
     }

transport-native-kqueue/src/main/java/io/netty/channel/kqueue/KQueueServerChannelConfig.java

@@ -31,6 +31,7 @@ import java.util.Map;
 import static io.netty.channel.ChannelOption.SO_BACKLOG;
 import static io.netty.channel.ChannelOption.SO_RCVBUF;
 import static io.netty.channel.ChannelOption.SO_REUSEADDR;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 @UnstableApi
 public class KQueueServerChannelConfig extends KQueueChannelConfig implements ServerSocketChannelConfig {
@@ -116,9 +117,7 @@ public class KQueueServerChannelConfig extends KQueueChannelConfig implements Se
     }
 
     public KQueueServerChannelConfig setBacklog(int backlog) {
-        if (backlog < 0) {
+        checkPositiveOrZero(backlog, "backlog");
-            throw new IllegalArgumentException("backlog: " + backlog);
-        }
         this.backlog = backlog;
         return this;
     }

transport-native-unix-common/src/main/java/io/netty/channel/unix/FileDescriptor.java

@@ -27,6 +27,7 @@ import static io.netty.channel.unix.Errors.ioResult;
 import static io.netty.channel.unix.Errors.newIOException;
 import static io.netty.channel.unix.Limits.IOV_MAX;
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 import static java.lang.Math.min;
 
 /**
@@ -82,9 +83,7 @@ public class FileDescriptor {
     final int fd;
 
     public FileDescriptor(int fd) {
-        if (fd < 0) {
+        checkPositiveOrZero(fd, "fd");
-            throw new IllegalArgumentException("fd must be >= 0");
-        }
         this.fd = fd;
     }
 

transport-sctp/src/main/java/io/netty/channel/sctp/DefaultSctpServerChannelConfig.java

@@ -15,6 +15,8 @@
 */
 package io.netty.channel.sctp;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import com.sun.nio.sctp.SctpServerChannel;
 import com.sun.nio.sctp.SctpStandardSocketOptions;
 import io.netty.buffer.ByteBufAllocator;
@@ -152,9 +154,7 @@ public class DefaultSctpServerChannelConfig extends DefaultChannelConfig impleme
 
     @Override
     public SctpServerChannelConfig setBacklog(int backlog) {
-        if (backlog < 0) {
+        checkPositiveOrZero(backlog, "backlog");
-            throw new IllegalArgumentException("backlog: " + backlog);
-        }
         this.backlog = backlog;
         return this;
     }

transport/src/main/java/io/netty/channel/AdaptiveRecvByteBufAllocator.java

@@ -18,6 +18,7 @@ package io.netty.channel;
 import java.util.ArrayList;
 import java.util.List;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
 import static java.lang.Math.max;
 import static java.lang.Math.min;
 
@@ -163,9 +164,7 @@ public class AdaptiveRecvByteBufAllocator extends DefaultMaxMessagesRecvByteBufA
      * @param maximum  the inclusive upper bound of the expected buffer size
      */
     public AdaptiveRecvByteBufAllocator(int minimum, int initial, int maximum) {
-        if (minimum <= 0) {
+        checkPositive(minimum, "minimum");
-            throw new IllegalArgumentException("minimum: " + minimum);
-        }
         if (initial < minimum) {
             throw new IllegalArgumentException("initial: " + initial);
         }

transport/src/main/java/io/netty/channel/ChannelFlushPromiseNotifier.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import java.util.ArrayDeque;
 import java.util.Queue;
 
@@ -64,9 +66,7 @@ public final class ChannelFlushPromiseNotifier {
         if (promise == null) {
             throw new NullPointerException("promise");
         }
-        if (pendingDataSize < 0) {
+        checkPositiveOrZero(pendingDataSize, "pendingDataSize");
-            throw new IllegalArgumentException("pendingDataSize must be >= 0 but was " + pendingDataSize);
-        }
         long checkpoint = writeCounter + pendingDataSize;
         if (promise instanceof FlushCheckpoint) {
             FlushCheckpoint cp = (FlushCheckpoint) promise;
@@ -81,9 +81,7 @@ public final class ChannelFlushPromiseNotifier {
      * Increase the current write counter by the given delta
      */
     public ChannelFlushPromiseNotifier increaseWriteCounter(long delta) {
-        if (delta < 0) {
+        checkPositiveOrZero(delta, "delta");
-            throw new IllegalArgumentException("delta must be >= 0 but was " + delta);
-        }
         writeCounter += delta;
         return this;
     }

transport/src/main/java/io/netty/channel/ChannelMetadata.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+
 import java.net.SocketAddress;
 
 /**
@@ -46,10 +48,7 @@ public final class ChannelMetadata {
      * set for {@link MaxMessagesRecvByteBufAllocator#maxMessagesPerRead()}. Must be {@code > 0}.
      */
     public ChannelMetadata(boolean hasDisconnect, int defaultMaxMessagesPerRead) {
-        if (defaultMaxMessagesPerRead <= 0) {
+        checkPositive(defaultMaxMessagesPerRead, "defaultMaxMessagesPerRead");
-            throw new IllegalArgumentException("defaultMaxMessagesPerRead: " + defaultMaxMessagesPerRead +
-                                               " (expected > 0)");
-        }
         this.hasDisconnect = hasDisconnect;
         this.defaultMaxMessagesPerRead = defaultMaxMessagesPerRead;
     }

transport/src/main/java/io/netty/channel/DefaultChannelConfig.java

@@ -36,6 +36,8 @@ import static io.netty.channel.ChannelOption.WRITE_BUFFER_LOW_WATER_MARK;
 import static io.netty.channel.ChannelOption.WRITE_BUFFER_WATER_MARK;
 import static io.netty.channel.ChannelOption.WRITE_SPIN_COUNT;
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 /**
  * The default {@link ChannelConfig} implementation.
@@ -209,10 +211,7 @@ public class DefaultChannelConfig implements ChannelConfig {
 
     @Override
     public ChannelConfig setConnectTimeoutMillis(int connectTimeoutMillis) {
-        if (connectTimeoutMillis < 0) {
+        checkPositiveOrZero(connectTimeoutMillis, "connectTimeoutMillis");
-            throw new IllegalArgumentException(String.format(
-                    "connectTimeoutMillis: %d (expected: >= 0)", connectTimeoutMillis));
-        }
         this.connectTimeoutMillis = connectTimeoutMillis;
         return this;
     }
@@ -261,10 +260,7 @@ public class DefaultChannelConfig implements ChannelConfig {
 
     @Override
     public ChannelConfig setWriteSpinCount(int writeSpinCount) {
-        if (writeSpinCount <= 0) {
+        checkPositive(writeSpinCount, "writeSpinCount");
-            throw new IllegalArgumentException(
-                    "writeSpinCount must be a positive integer.");
-        }
         // Integer.MAX_VALUE is used as a special value in the channel implementations to indicate the channel cannot
         // accept any more data, and results in the writeOp being set on the selector (or execute a runnable which tries
         // to flush later because the writeSpinCount quantum has been exhausted). This strategy prevents additional
@@ -357,10 +353,7 @@ public class DefaultChannelConfig implements ChannelConfig {
 
     @Override
     public ChannelConfig setWriteBufferHighWaterMark(int writeBufferHighWaterMark) {
-        if (writeBufferHighWaterMark < 0) {
+        checkPositiveOrZero(writeBufferHighWaterMark, "writeBufferHighWaterMark");
-            throw new IllegalArgumentException(
-                    "writeBufferHighWaterMark must be >= 0");
-        }
         for (;;) {
             WriteBufferWaterMark waterMark = writeBufferWaterMark;
             if (writeBufferHighWaterMark < waterMark.low()) {
@@ -383,10 +376,7 @@ public class DefaultChannelConfig implements ChannelConfig {
 
     @Override
     public ChannelConfig setWriteBufferLowWaterMark(int writeBufferLowWaterMark) {
-        if (writeBufferLowWaterMark < 0) {
+        checkPositiveOrZero(writeBufferLowWaterMark, "writeBufferLowWaterMark");
-            throw new IllegalArgumentException(
-                    "writeBufferLowWaterMark must be >= 0");
-        }
         for (;;) {
             WriteBufferWaterMark waterMark = writeBufferWaterMark;
             if (writeBufferLowWaterMark > waterMark.high()) {

transport/src/main/java/io/netty/channel/DefaultFileRegion.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.util.AbstractReferenceCounted;
 import io.netty.util.IllegalReferenceCountException;
 import io.netty.util.internal.logging.InternalLogger;
@@ -52,12 +54,8 @@ public class DefaultFileRegion extends AbstractReferenceCounted implements FileR
         if (file == null) {
             throw new NullPointerException("file");
         }
-        if (position < 0) {
+        checkPositiveOrZero(position, "position");
-            throw new IllegalArgumentException("position must be >= 0 but was " + position);
+        checkPositiveOrZero(count, "count");
-        }
-        if (count < 0) {
-            throw new IllegalArgumentException("count must be >= 0 but was " + count);
-        }
         this.file = file;
         this.position = position;
         this.count = count;
@@ -76,12 +74,8 @@ public class DefaultFileRegion extends AbstractReferenceCounted implements FileR
         if (f == null) {
             throw new NullPointerException("f");
         }
-        if (position < 0) {
+        checkPositiveOrZero(position, "position");
-            throw new IllegalArgumentException("position must be >= 0 but was " + position);
+        checkPositiveOrZero(count, "count");
-        }
-        if (count < 0) {
-            throw new IllegalArgumentException("count must be >= 0 but was " + count);
-        }
         this.position = position;
         this.count = count;
         this.f = f;

transport/src/main/java/io/netty/channel/DefaultMaxBytesRecvByteBufAllocator.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
 import io.netty.util.UncheckedBooleanSupplier;
@@ -124,9 +126,7 @@ public class DefaultMaxBytesRecvByteBufAllocator implements MaxBytesRecvByteBufA
 
     @Override
     public DefaultMaxBytesRecvByteBufAllocator maxBytesPerRead(int maxBytesPerRead) {
-        if (maxBytesPerRead <= 0) {
+        checkPositive(maxBytesPerRead, "maxBytesPerRead");
-            throw new IllegalArgumentException("maxBytesPerRead: " + maxBytesPerRead + " (expected: > 0)");
-        }
         // There is a dependency between this.maxBytesPerRead and this.maxBytesPerIndividualRead (a < b).
         // Write operations must be synchronized, but independent read operations can just be volatile.
         synchronized (this) {
@@ -149,10 +149,7 @@ public class DefaultMaxBytesRecvByteBufAllocator implements MaxBytesRecvByteBufA
 
     @Override
     public DefaultMaxBytesRecvByteBufAllocator maxBytesPerIndividualRead(int maxBytesPerIndividualRead) {
-        if (maxBytesPerIndividualRead <= 0) {
+        checkPositive(maxBytesPerIndividualRead, "maxBytesPerIndividualRead");
-            throw new IllegalArgumentException(
-                    "maxBytesPerIndividualRead: " + maxBytesPerIndividualRead + " (expected: > 0)");
-        }
         // There is a dependency between this.maxBytesPerRead and this.maxBytesPerIndividualRead (a < b).
         // Write operations must be synchronized, but independent read operations can just be volatile.
         synchronized (this) {
@@ -174,13 +171,8 @@ public class DefaultMaxBytesRecvByteBufAllocator implements MaxBytesRecvByteBufA
     }
 
     private static void checkMaxBytesPerReadPair(int maxBytesPerRead, int maxBytesPerIndividualRead) {
-        if (maxBytesPerRead <= 0) {
+        checkPositive(maxBytesPerRead, "maxBytesPerRead");
-            throw new IllegalArgumentException("maxBytesPerRead: " + maxBytesPerRead + " (expected: > 0)");
+        checkPositive(maxBytesPerIndividualRead, "maxBytesPerIndividualRead");
-        }
-        if (maxBytesPerIndividualRead <= 0) {
-            throw new IllegalArgumentException(
-                    "maxBytesPerIndividualRead: " + maxBytesPerIndividualRead + " (expected: > 0)");
-        }
         if (maxBytesPerRead < maxBytesPerIndividualRead) {
             throw new IllegalArgumentException(
                     "maxBytesPerRead cannot be less than " +

transport/src/main/java/io/netty/channel/DefaultMaxMessagesRecvByteBufAllocator.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
 import io.netty.util.UncheckedBooleanSupplier;
@@ -42,9 +44,7 @@ public abstract class DefaultMaxMessagesRecvByteBufAllocator implements MaxMessa
 
     @Override
     public MaxMessagesRecvByteBufAllocator maxMessagesPerRead(int maxMessagesPerRead) {
-        if (maxMessagesPerRead <= 0) {
+        checkPositive(maxMessagesPerRead, "maxMessagesPerRead");
-            throw new IllegalArgumentException("maxMessagesPerRead: " + maxMessagesPerRead + " (expected: > 0)");
-        }
         this.maxMessagesPerRead = maxMessagesPerRead;
         return this;
     }

transport/src/main/java/io/netty/channel/DefaultMessageSizeEstimator.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufHolder;
 
@@ -59,9 +61,7 @@ public final class DefaultMessageSizeEstimator implements MessageSizeEstimator {
      * @param unknownSize       The size which is returned for unknown messages.
      */
     public DefaultMessageSizeEstimator(int unknownSize) {
-        if (unknownSize < 0) {
+        checkPositiveOrZero(unknownSize, "unknownSize");
-            throw new IllegalArgumentException("unknownSize: " + unknownSize + " (expected: >= 0)");
-        }
         handle = new HandleImpl(unknownSize);
     }
 

transport/src/main/java/io/netty/channel/FixedRecvByteBufAllocator.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositive;
+
 /**
  * The {@link RecvByteBufAllocator} that always yields the same buffer
  * size prediction.  This predictor ignores the feed back from the I/O thread.
@@ -41,10 +43,7 @@ public class FixedRecvByteBufAllocator extends DefaultMaxMessagesRecvByteBufAllo
      * the specified buffer size.
      */
     public FixedRecvByteBufAllocator(int bufferSize) {
-        if (bufferSize <= 0) {
+        checkPositive(bufferSize, "bufferSize");
-            throw new IllegalArgumentException(
-                    "bufferSize must greater than 0: " + bufferSize);
-        }
         this.bufferSize = bufferSize;
     }
 

transport/src/main/java/io/netty/channel/WriteBufferWaterMark.java

@@ -15,6 +15,8 @@
  */
 package io.netty.channel;
 
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
+
 /**
  * WriteBufferWaterMark is used to set low water mark and high water mark for the write buffer.
  * <p>
@@ -54,9 +56,7 @@ public final class WriteBufferWaterMark {
      */
     WriteBufferWaterMark(int low, int high, boolean validate) {
         if (validate) {
-            if (low < 0) {
+            checkPositiveOrZero(low, "low");
-                throw new IllegalArgumentException("write buffer's low water mark must be >= 0");
-            }
             if (high < low) {
                 throw new IllegalArgumentException(
                         "write buffer's high water mark cannot be less than " +

transport/src/main/java/io/netty/channel/socket/DefaultServerSocketChannelConfig.java

@@ -31,6 +31,7 @@ import java.util.Map;
 import static io.netty.channel.ChannelOption.SO_BACKLOG;
 import static io.netty.channel.ChannelOption.SO_RCVBUF;
 import static io.netty.channel.ChannelOption.SO_REUSEADDR;
+import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 /**
  * The default {@link ServerSocketChannelConfig} implementation.
@@ -141,9 +142,7 @@ public class DefaultServerSocketChannelConfig extends DefaultChannelConfig
 
     @Override
     public ServerSocketChannelConfig setBacklog(int backlog) {
-        if (backlog < 0) {
+        checkPositiveOrZero(backlog, "backlog");
-            throw new IllegalArgumentException("backlog: " + backlog);
-        }
         this.backlog = backlog;
         return this;
     }