Require Java8 as minimum (#8739)

Motivation:

While we are not yet quite sure if we want to require Java11 as minimum we are at least sure we want to use java8 as minimum.

Modifications:

Change minimum version to java8 and update some tests which failed compilation after this change.

Result:

Use Java8 as minimum and be able to use Java8 features.

codec-http/src/test/java/io/netty/handler/codec/http/websocketx/WebSocketServerHandshaker00Test.java

@@ -15,6 +15,7 @@
  */
 package io.netty.handler.codec.http.websocketx;
 
+import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http.DefaultFullHttpRequest;
@@ -70,7 +71,7 @@ public class WebSocketServerHandshaker00Test {
         }
 
         EmbeddedChannel ch2 = new EmbeddedChannel(new HttpResponseDecoder());
-        ch2.writeInbound(ch.readOutbound());
+        ch2.writeInbound((ByteBuf) ch.readOutbound());
         HttpResponse res = ch2.readInbound();
 
         Assert.assertEquals("ws://example.com/chat", res.headers().get(HttpHeaderNames.SEC_WEBSOCKET_LOCATION));

codec-socks/src/test/java/io/netty/handler/codec/socksx/v4/Socks4CommonTestUtils.java

@@ -33,7 +33,7 @@ final class Socks4CommonTestUtils {
             out = new EmbeddedChannel(Socks4ServerEncoder.INSTANCE);
         }
         out.writeOutbound(msg);
-        embedder.writeInbound(out.readOutbound());
+        embedder.writeInbound((Object) out.readOutbound());
         out.finish();
     }
 }

codec/src/test/java/io/netty/handler/codec/ByteToMessageCodecTest.java

@@ -62,7 +62,7 @@ public class ByteToMessageCodecTest {
         assertTrue(ch.writeInbound(buffer));
         ch.pipeline().remove(codec);
         assertTrue(ch.finish());
-        assertEquals(1, ch.readInbound());
+        assertEquals(1, (int) ch.readInbound());
 
         ByteBuf buf = (ByteBuf) ch.readInbound();
         assertEquals(Unpooled.wrappedBuffer(new byte[]{'0'}), buf);

handler/src/test/java/io/netty/handler/flush/FlushConsolidationHandlerTest.java

@@ -86,8 +86,8 @@ public class FlushConsolidationHandlerTest {
         channel.flush();
         channel.runPendingTasks();
         assertEquals(3, flushCount.get());
-        assertEquals(1L, channel.readOutbound());
-        assertEquals(2L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
+        assertEquals(2L, (long) channel.readOutbound());
         assertNull(channel.readOutbound());
         assertFalse(channel.finish());
     }
@@ -102,7 +102,7 @@ public class FlushConsolidationHandlerTest {
         assertNull(channel.readOutbound());
         channel.close();
         assertEquals(1, flushCount.get());
-        assertEquals(1L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
         assertNull(channel.readOutbound());
         assertFalse(channel.finish());
     }
@@ -117,7 +117,7 @@ public class FlushConsolidationHandlerTest {
         assertNull(channel.readOutbound());
         channel.disconnect();
         assertEquals(1, flushCount.get());
-        assertEquals(1L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
         assertNull(channel.readOutbound());
         assertFalse(channel.finish());
     }
@@ -132,7 +132,7 @@ public class FlushConsolidationHandlerTest {
         assertNull(channel.readOutbound());
         channel.pipeline().fireExceptionCaught(new IllegalStateException());
         assertEquals(1, flushCount.get());
-        assertEquals(1L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
         assertNull(channel.readOutbound());
         channel.finish();
     }
@@ -147,7 +147,7 @@ public class FlushConsolidationHandlerTest {
         assertNull(channel.readOutbound());
         channel.pipeline().remove(FlushConsolidationHandler.class);
         assertEquals(1, flushCount.get());
-        assertEquals(1L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
         assertNull(channel.readOutbound());
         assertFalse(channel.finish());
     }

handler/src/test/java/io/netty/handler/stream/ChunkedWriteHandlerTest.java

@@ -223,7 +223,7 @@ public class ChunkedWriteHandlerTest {
         ch.writeAndFlush(input).syncUninterruptibly();
         assertTrue(ch.finish());
 
-        assertEquals(0, ch.readOutbound());
+        assertEquals(0, (int) ch.readOutbound());
         assertNull(ch.readOutbound());
     }
 

pom.xml

@@ -82,9 +82,6 @@
         <enforcer.plugin.version>3.0.0-M1</enforcer.plugin.version>
         <!-- 1.4.x does not work in Java10+ -->
         <jboss.marshalling.version>2.0.5.Final</jboss.marshalling.version>
-        <!-- This is the minimum supported by Java12 -->
-        <maven.compiler.source>1.7</maven.compiler.source>
-        <maven.compiler.target>1.7</maven.compiler.target>
         <!-- pax-exam does not work on latest Java12 EA 22 build -->
         <skipOsgiTestsuite>true</skipOsgiTestsuite>
       </properties>
@@ -104,9 +101,6 @@
         <enforcer.plugin.version>3.0.0-M1</enforcer.plugin.version>
         <!-- 1.4.x does not work in Java10+ -->
         <jboss.marshalling.version>2.0.5.Final</jboss.marshalling.version>
-        <!-- This is the minimum supported by Java12 -->
-        <maven.compiler.source>1.7</maven.compiler.source>
-        <maven.compiler.target>1.7</maven.compiler.target>
         <!-- pax-exam does not work on latest Java12 EA 22 build -->
         <skipOsgiTestsuite>true</skipOsgiTestsuite>
       </properties>
@@ -248,8 +242,8 @@
   </profiles>
 
   <properties>
-    <maven.compiler.source>1.6</maven.compiler.source>
-    <maven.compiler.target>1.6</maven.compiler.target>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <maven.compiler.target>1.8</maven.compiler.target>
     <netty.dev.tools.directory>${project.build.directory}/dev-tools</netty.dev.tools.directory>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
@@ -724,27 +718,14 @@
         <configuration>
           <signature>
             <groupId>org.codehaus.mojo.signature</groupId>
-            <artifactId>java16</artifactId>
-            <version>1.1</version>
+            <artifactId>java18</artifactId>
+            <version>1.0</version>
           </signature>
           <ignores>
             <ignore>sun.misc.Unsafe</ignore>
             <ignore>sun.misc.Cleaner</ignore>
             <ignore>sun.nio.ch.DirectBuffer</ignore>
 
-            <ignore>java.util.zip.Deflater</ignore>
-
-            <!-- Used for NIO -->
-            <ignore>java.nio.channels.DatagramChannel</ignore>
-            <ignore>java.nio.channels.MembershipKey</ignore>
-            <ignore>java.nio.channels.ServerSocketChannel</ignore>
-            <ignore>java.nio.channels.SocketChannel</ignore>
-            <ignore>java.net.StandardProtocolFamily</ignore>
-            <ignore>java.nio.channels.spi.SelectorProvider</ignore>
-            <ignore>java.net.SocketOption</ignore> 
-            <ignore>java.net.StandardSocketOptions</ignore> 
-            <ignore>java.nio.channels.NetworkChannel</ignore>
-
             <!-- Self-signed certificate generation -->
             <ignore>sun.security.x509.AlgorithmId</ignore>
             <ignore>sun.security.x509.CertificateAlgorithmId</ignore>
@@ -757,49 +738,6 @@
             <ignore>sun.security.x509.X500Name</ignore>
             <ignore>sun.security.x509.X509CertInfo</ignore>
             <ignore>sun.security.x509.X509CertImpl</ignore>
-
-            <!-- SSLSession implementation -->
-            <ignore>javax.net.ssl.SSLEngine</ignore>
-            <ignore>javax.net.ssl.ExtendedSSLSession</ignore>
-            <ignore>javax.net.ssl.X509ExtendedTrustManager</ignore>
-            <ignore>javax.net.ssl.SSLParameters</ignore>
-            <ignore>javax.net.ssl.SNIServerName</ignore>
-            <ignore>javax.net.ssl.SNIHostName</ignore>
-            <ignore>javax.net.ssl.SNIMatcher</ignore>
-            <ignore>java.security.AlgorithmConstraints</ignore>
-            <ignore>java.security.cert.CertificateRevokedException</ignore>
-            <ignore>java.security.cert.CertPathValidatorException</ignore>
-            <ignore>java.security.cert.CertPathValidatorException$Reason</ignore>
-            <ignore>java.security.cert.CertPathValidatorException$BasicReason</ignore>
-
-            <ignore>java.util.concurrent.ConcurrentLinkedDeque</ignore>
-            <ignore>java.util.concurrent.ThreadLocalRandom</ignore>
-
-            <!-- Compression -->
-            <ignore>java.util.zip.CRC32</ignore>
-            <ignore>java.util.zip.Adler32</ignore>
-
-            <!-- NioDatagramChannel implementation -->
-            <ignore>java.net.ProtocolFamily</ignore>
-
-            <!-- JDK 9 -->
-            <ignore>java.nio.ByteBuffer</ignore>
-            <ignore>java.nio.CharBuffer</ignore>
-
-            <!-- JDK 8 -->
-            <ignore>java.util.concurrent.atomic.LongAdder</ignore>
-            <ignore>java.util.function.BiFunction</ignore>
-            <ignore>java.security.cert.X509Certificate</ignore>
-
-            <!-- Resolver -->
-            <ignore>java.net.InetAddress</ignore>
-
-            <!-- NoexecVolumeDetector -->
-            <ignore>java.nio.file.attribute.PosixFilePermission</ignore>
-            <ignore>java.nio.file.Files</ignore>
-            <ignore>java.nio.file.LinkOption</ignore>
-            <ignore>java.nio.file.Path</ignore>
-            <ignore>java.io.File</ignore>
           </ignores>
           <annotations>
             <annotation>io.netty.util.internal.SuppressJava6Requirement</annotation>

transport/src/test/java/io/netty/channel/PendingWriteQueueTest.java

@@ -259,9 +259,9 @@ public class PendingWriteQueueTest {
         assertTrue(promise3.isDone());
         assertTrue(promise3.isSuccess());
         assertTrue(channel.finish());
-        assertEquals(1L, channel.readOutbound());
-        assertEquals(2L, channel.readOutbound());
-        assertEquals(3L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
+        assertEquals(2L, (long) channel.readOutbound());
+        assertEquals(3L, (long) channel.readOutbound());
     }
 
     @Test
@@ -284,8 +284,8 @@ public class PendingWriteQueueTest {
         assertTrue(channel.finish());
         assertTrue(promise.isDone());
         assertTrue(promise.isSuccess());
-        assertEquals(1L, channel.readOutbound());
-        assertEquals(2L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
+        assertEquals(2L, (long) channel.readOutbound());
     }
 
     @Test
@@ -354,8 +354,8 @@ public class PendingWriteQueueTest {
         assertTrue(promise2.isSuccess());
         assertTrue(channel.finish());
 
-        assertEquals(1L, channel.readOutbound());
-        assertEquals(2L, channel.readOutbound());
+        assertEquals(1L, (long) channel.readOutbound());
+        assertEquals(2L, (long) channel.readOutbound());
         assertNull(channel.readOutbound());
         assertNull(channel.readInbound());
     }