Code modernization

src/main/java/hudson/remoting/AbstractByteArrayCommandTransport.java

@@ -78,9 +78,9 @@ public void terminate(IOException e) {
     @Override
     public final void write(Command cmd, boolean last) throws IOException {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        ObjectOutputStream oos = AnonymousClassWarnings.checkingObjectOutputStream(baos);
-        cmd.writeTo(channel,oos);
-        oos.close();
+        try (ObjectOutputStream oos = AnonymousClassWarnings.checkingObjectOutputStream(baos)) {
+            cmd.writeTo(channel, oos);
+        }
         byte[] block = baos.toByteArray();
         channel.notifyWrite(cmd, block.length);
         writeBlock(channel, block);

src/main/java/hudson/remoting/AbstractSynchronousByteArrayCommandTransport.java

@@ -38,9 +38,9 @@ public Command read() throws IOException, ClassNotFoundException {
     @Override
     public void write(Command cmd, boolean last) throws IOException {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        ObjectOutputStream oos = AnonymousClassWarnings.checkingObjectOutputStream(baos);
-        cmd.writeTo(channel,oos);
-        oos.close();
+        try (ObjectOutputStream oos = AnonymousClassWarnings.checkingObjectOutputStream(baos)) {
+            cmd.writeTo(channel, oos);
+        }
         byte[] block = baos.toByteArray();
         channel.notifyWrite(cmd, block.length);
         writeBlock(channel, block);

src/main/java/hudson/remoting/Channel.java

@@ -1027,7 +1027,7 @@ Future<V> callAsync(final Callable<V,T> callable) throws IOException {
         }
 
         final Future<UserRequest.ResponseToUserRequest<V, T>> f = new UserRequest<V, T>(this, callable).callAsync(this);
-        return new FutureAdapter<V, UserRequest.ResponseToUserRequest<V, T>>(f) {
+        return new FutureAdapter<>(f) {
             @Override
             protected V adapt(UserRequest.ResponseToUserRequest<V, T> r) throws ExecutionException {
                 try {
@@ -2125,11 +2125,7 @@ public int hashCode() {
          */
         @Override
         public String toString() {
-            final StringBuilder sb = new StringBuilder("Channel.Ref{");
-            sb.append("channel=").append(channel);
-            sb.append(",name=").append(name);
-            sb.append('}');
-            return sb.toString();
+            return "Channel.Ref{channel=" + channel + ",name=" + name + "}";
         }
     }
 }

src/main/java/hudson/remoting/Command.java

@@ -187,7 +187,7 @@ private Source(@CheckForNull Throwable cause) {
 
         @Override
         public String toString() {
-            return "Command "+Command.this.toString()+" created at";
+            return "Command " + Command.this + " created at";
         }
 
         private static final long serialVersionUID = 1L;

src/main/java/hudson/remoting/ExportTable.java

@@ -178,15 +178,13 @@ void dump(PrintWriter w) throws IOException {
         }
 
         String dump() {
-            try {
-                StringWriter sw = new StringWriter();
-                PrintWriter pw = new PrintWriter(sw);
+            StringWriter sw = new StringWriter();
+            try (PrintWriter pw = new PrintWriter(sw)) {
                 dump(pw);
-                pw.close();
-                return sw.toString();
             } catch (IOException e) {
                 throw new Error(e);   // impossible
             }
+            return sw.toString();
         }
 
         synchronized Class<? super T>[] getInterfaces() {

src/main/java/hudson/remoting/LocalChannel.java

@@ -59,7 +59,7 @@ public <V, T extends Throwable> Future<V> callAsync(@NonNull final Callable<V,T>
             }
         });
 
-        return new Future<V>() {
+        return new Future<>() {
             @Override
             public boolean cancel(boolean mayInterruptIfRunning) {
                 return f.cancel(mayInterruptIfRunning);
@@ -82,7 +82,7 @@ public V get() throws InterruptedException, ExecutionException {
 
             @Override
             public V get(long timeout, @NonNull TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
-                return f.get(timeout,unit);
+                return f.get(timeout, unit);
             }
         };
     }

src/main/java/hudson/remoting/ProxyInputStream.java

@@ -24,6 +24,7 @@
 package hudson.remoting;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
+import org.jenkinsci.remoting.util.IOUtils;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -176,12 +177,7 @@ protected void execute(Channel channel) {
             }
 
             channel.unexport(oid,createdAt,false);
-
-            try {
-                in.close();
-            } catch (IOException e) {
-                // ignore errors
-            }
+            IOUtils.closeQuietly(in);
         }
 
         @Override

src/main/java/hudson/remoting/RemoteClassLoader.java

@@ -1195,7 +1195,7 @@ public int hashCode() {
 
         @Override
         public String toString() {
-            return super.toString() + '[' + cl.toString() + ']';
+            return super.toString() + '[' + cl + ']';
         }
 
         /**

src/main/java/hudson/remoting/RemoteInputStream.java

@@ -254,9 +254,9 @@ public enum Flag {
     private static final class Greedy extends Exception {
         public String print() {
             StringWriter sw = new StringWriter();
-            PrintWriter pw = new PrintWriter(sw);
-            printStackTrace(pw);
-            pw.close();
+            try (PrintWriter pw = new PrintWriter(sw)) {
+                printStackTrace(pw);
+            }
             return sw.toString();
         }
     }

src/main/java/hudson/remoting/RemoteInvocationHandler.java

@@ -140,7 +140,7 @@ private RemoteInvocationHandler(Channel channel, int id, boolean userProxy,
         this.channel = channel == null ? null : channel.ref();
         this.oid = id;
         this.userProxy = userProxy;
-        this.origin = recordCreatedAt ? new Exception("Proxy " + toString() + " was created for " + proxyType) : null;
+        this.origin = recordCreatedAt ? new Exception("Proxy " + this + " was created for " + proxyType) : null;
         this.autoUnexportByCaller = autoUnexportByCaller;
         this.userSpace = userSpace;
         this.recordCreatedAt = recordCreatedAt;

src/main/java/hudson/remoting/Request.java

@@ -237,7 +237,7 @@ final hudson.remoting.Future<RSP> callAsync(final Channel channel) throws IOExce
         startTime = System.nanoTime();
         channel.send(this);
 
-        return new hudson.remoting.Future<RSP>() {
+        return new hudson.remoting.Future<>() {
 
             private volatile boolean cancelled;
 
@@ -264,23 +264,23 @@ public boolean isCancelled() {
 
             @Override
             public boolean isDone() {
-                return isCancelled() || response!=null;
+                return isCancelled() || response != null;
             }
 
             @Override
             public RSP get() throws InterruptedException, ExecutionException {
-                synchronized(Request.this) {
+                synchronized (Request.this) {
                     String oldThreadName = Thread.currentThread().getName();
-                    Thread.currentThread().setName(oldThreadName+" for "+channel.getName()+" id="+id);
+                    Thread.currentThread().setName(oldThreadName + " for " + channel.getName() + " id=" + id);
                     try {
-                        while(response==null) {
+                        while (response == null) {
                             if (isCancelled()) {
                                 throw new CancellationException();
                             }
                             if (channel.isInClosed()) {
                                 throw new ExecutionException(new RequestAbortedException(null));
                             }
-                            Request.this.wait(30*1000); // wait until the response arrives
+                            Request.this.wait(30 * 1000); // wait until the response arrives
                         }
                     } catch (InterruptedException e) {
                         try {
@@ -293,8 +293,9 @@ public RSP get() throws InterruptedException, ExecutionException {
                         Thread.currentThread().setName(oldThreadName);
                     }
 
-                    if(response.exception!=null)
+                    if (response.exception != null) {
                         throw new ExecutionException(response.exception);
+                    }
 
                     return response.returnValue;
                 }
@@ -314,7 +315,7 @@ public RSP get(long timeout, @NonNull TimeUnit unit) throws InterruptedException
                         if (channel.isInClosed()) {
                             throw new ExecutionException(new RequestAbortedException(null));
                         }
-                        Request.this.wait(Math.min(30*1000,Math.max(1, TimeUnit.NANOSECONDS.toMillis(end - now))));
+                        Request.this.wait(Math.min(30 * 1000, Math.max(1, TimeUnit.NANOSECONDS.toMillis(end - now))));
                         now = System.nanoTime();
                     }
                     if (response == null)

src/main/java/hudson/remoting/ResourceImageInJar.java

@@ -42,12 +42,12 @@ class ResourceImageInJar extends ResourceImageRef {
 
     @Override
     Future<byte[]> resolve(Channel channel, final String resourcePath) throws IOException, InterruptedException {
-        return new FutureAdapter<byte[],URL>(_resolveJarURL(channel)) {
+        return new FutureAdapter<>(_resolveJarURL(channel)) {
             @Override
             @SuppressFBWarnings(value = "URLCONNECTION_SSRF_FD", justification = "This is only used for managing the jar cache as files.")
             protected byte[] adapt(URL jar) throws ExecutionException {
                 try {
-                    return Util.readFully(toResourceURL(jar,resourcePath).openStream());
+                    return Util.readFully(toResourceURL(jar, resourcePath).openStream());
                 } catch (IOException e) {
                     throw new ExecutionException(e);
                 }
@@ -57,7 +57,7 @@ protected byte[] adapt(URL jar) throws ExecutionException {
 
     @Override
     Future<URLish> resolveURL(Channel channel, final String resourcePath) throws IOException, InterruptedException {
-        return new FutureAdapter<URLish,URL>(_resolveJarURL(channel)) {
+        return new FutureAdapter<>(_resolveJarURL(channel)) {
             @Override
             protected URLish adapt(URL jar) throws ExecutionException {
                 try {

src/main/java/hudson/remoting/UserRequest.java

@@ -213,7 +213,7 @@ protected ResponseToUserRequest<RSP,EXC> perform(Channel channel) throws EXC {
                     Thread.currentThread().setContextClassLoader(old);
                 }
             } catch (LinkageError e) {
-                LOGGER.log(channel.isClosingOrClosed() ? Level.FINE : Level.WARNING, "LinkageError while performing " + toString(), e);
+                LOGGER.log(channel.isClosingOrClosed() ? Level.FINE : Level.WARNING, "LinkageError while performing " + this, e);
                 throw e;
             } finally {
                 Channel.setCurrent(oldc);

src/main/java/hudson/remoting/Util.java

@@ -51,13 +51,12 @@ static byte[] readFully(InputStream in) throws IOException {
     }
 
     public static void copy(InputStream in, OutputStream out) throws IOException {
-        try {
+        try (in) {
             byte[] buf = new byte[8192];
             int len;
-            while((len=in.read(buf))>0)
-                out.write(buf,0,len);
-        } finally {
-            in.close();
+            while ((len = in.read(buf)) > 0) {
+                out.write(buf, 0, len);
+            }
         }
     }
 

src/main/java/org/jenkinsci/remoting/engine/JnlpAgentEndpoint.java

@@ -243,7 +243,7 @@ public Socket open(int socketTimeout) throws IOException {
             }
             String suffix = "";
             if (isHttpProxy) {
-                suffix = " through proxy " + targetAddress.toString();
+                suffix = " through proxy " + targetAddress;
             }
             throw new IOException("Failed to connect to " + host + ':' + port + suffix, e);
         }

src/main/java/org/jenkinsci/remoting/engine/JnlpProtocol4Handler.java

@@ -59,6 +59,7 @@
 import org.jenkinsci.remoting.protocol.impl.ConnectionRefusalException;
 import org.jenkinsci.remoting.protocol.impl.NIONetworkLayer;
 import org.jenkinsci.remoting.protocol.impl.SSLEngineFilterLayer;
+import org.jenkinsci.remoting.util.IOUtils;
 
 /**
  * Implements the JNLP4-connect protocol. This protocol uses {@link SSLEngine} to perform a TLS upgrade of the plaintext
@@ -359,11 +360,7 @@ public void onClosed(Channel channel, IOException cause) {
             }
             event.fireChannelClosed(cause);
             channel.removeListener(this);
-            try {
-                event.getSocket().close();
-            } catch (IOException e) {
-                // ignore
-            }
+            IOUtils.closeQuietly(event.getSocket());
         }
 
         /**
@@ -375,11 +372,7 @@ public void onClosed(ProtocolStack<?> stack, IOException cause) {
                 event.fireAfterDisconnect();
             } finally {
                 stack.removeListener(this);
-                try {
-                    event.getSocket().close();
-                } catch (IOException e) {
-                    // ignore
-                }
+                IOUtils.closeQuietly(event.getSocket());
             }
         }
     }

src/main/java/org/jenkinsci/remoting/nio/FifoBuffer.java

@@ -453,19 +453,6 @@ private void releaseRing() {
             r = w = null;
     }
 
-//    /**
-//     * Returns a {@link ByteBuffer} for peeking into
-//     */
-//    public ByteBuffer peek(int max) {
-//        synchronized (lock) {
-//            if (closed) {
-//                releaseRing();
-//                return null;
-//            }
-//            return r.asBuffer(Math.min(max, readable()));
-//        }
-//    }
-
     /**
      * Peek the specified number of bytes ({@code len}) at the specified offset in this buffer ({@code offset})
      * and places it into the specified position ({@code start}) of the array ({@code data})

src/main/java/org/jenkinsci/remoting/org/apache/commons/net/util/SubnetUtils.java

@@ -239,15 +239,13 @@ public String[] getAllAddresses() {
          */
         @Override
         public String toString() {
-            final StringBuilder buf = new StringBuilder();
-            buf.append("CIDR Signature:\t[").append(getCidrSignature()).append("]")
-                .append(" Netmask: [").append(getNetmask()).append("]\n")
-                .append("Network:\t[").append(getNetworkAddress()).append("]\n")
-                .append("Broadcast:\t[").append(getBroadcastAddress()).append("]\n")
-                 .append("First Address:\t[").append(getLowAddress()).append("]\n")
-                 .append("Last Address:\t[").append(getHighAddress()).append("]\n")
-                 .append("# Addresses:\t[").append(getAddressCount()).append("]\n");
-            return buf.toString();
+            return "CIDR Signature:\t[" + getCidrSignature() + "]" +
+                    " Netmask: [" + getNetmask() + "]\n" +
+                    "Network:\t[" + getNetworkAddress() + "]\n" +
+                    "Broadcast:\t[" + getBroadcastAddress() + "]\n" +
+                    "First Address:\t[" + getLowAddress() + "]\n" +
+                    "Last Address:\t[" + getHighAddress() + "]\n" +
+                    "# Addresses:\t[" + getAddressCount() + "]\n";
         }
     }
 

src/main/java/org/jenkinsci/remoting/org/apache/commons/validator/routines/InetAddressValidator.java

@@ -149,7 +149,7 @@ public boolean isValidInet6Address(String inet6Address) {
             } else if (inet6Address.startsWith("::") && !octetList.isEmpty()) {
                 octetList.remove(0);
             }
-            octets = octetList.toArray(new String[octetList.size()]);
+            octets = octetList.toArray(new String[0]);
         }
         if (octets.length > IPV6_MAX_HEX_GROUPS) {
             return false;

src/test/java/Driver8703.java

@@ -15,11 +15,6 @@
 public class Driver8703 {
     @Issue("JENKINS-8703")
     public static void main(String[] args) throws Throwable {
-//        int i=0;
-//        while (true) {
-//            System.out.println(i++);
-//            foo();
-//        }
 
         ExecutorService es = Executors.newCachedThreadPool();
         List<Future<Object>> flist = new ArrayList<>();

src/test/java/OISInterception.java

@@ -14,10 +14,9 @@
 public class OISInterception {
     public static void main(String[] args) throws Exception {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        ObjectOutputStream oos = new ObjectOutputStream(baos);
-
-        oos.writeObject(Set.of("foo"));
-        oos.close();
+        try (ObjectOutputStream oos = new ObjectOutputStream(baos) ) {
+            oos.writeObject(Set.of("foo"));
+        }
 
         ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray())) {
             @Override