All methods that refer to types defined in the java.awt.peer and java.awt.dnd.peer packages (the "peer types") were removed from the Java API in Java SE 9 . Application code which calls any such method which accepts or returns a type defined in these packages will no longer link. This is a BINARY incompatible change.

Additional information is provided here: http://mail.openjdk.java.net/pipermail/awt-dev/2015-February/008924.html

com.sun.image.codec.jpeg has been shipped as a non-standard API since JDK 1.2. It was always advertised as a stop-gap measure until a proper standard equivalent was provided. That replacement (javax.imageio) has been there since JDK 1.4. As a result JDK 9 finally removes the long deprecated com.sun.image.codec.jpeg API which has been flagged as intended for removal for several releases. Applications which still depend on it will need to be re-coded in order to run on JDK9.

The public static constant JFrame.EXIT_ON_CLOSE was removed in favour of WindowConstants.EXIT_ON_CLOSE.

The default java.policy no longer grants stopThread runtime permission in JDK 9.

In previous releases, untrusted code had the stopThread runtime permission by default. This allows untrusted code to call Thread::stop ( on threads other than the current one ). Having an arbitrary exception thrown asynchronously is not something that trusted code should be expected to handle gracefully. So this permission is removed by default in JDK 9. The following line is deleted from the file conf/security/java.policy : permission java.lang.RuntimePermission "stopThread";

The system property sun.lang.ClassLoader.allowArraySyntax was introduced as a temporary workaround to give customers time to remove their source dependency on calling ClassLoader.loadClass with the array syntax that is not supported since JDK 6. This temporary workaround is removed in JDK 9 and setting sun.lang.ClassLoader.allowArraySyntax system property will have no effect to ClassLoader.loadClass. Existing code that calls ClassLoader.loadClass to create a Class object of an array class shall be replaced with Class.forName; otherwise it will get ClassNotFoundException.

The netdoc protocol handler has been removed in JDK 9. Code that attempts to construct a java.net.URL with the netdoc protocol, for example "netdoc:http://foo.com/index.html" will throw a MalformedURLException.

The netdoc protocol was used to point to network documents either on the local file system or externally through an HTTP URL. This capability is essentially defunct and is not supported by Safari, Firefox, and other major browsers.

The lib/content-types.properties file has been removed from the Java run-time image. The lib/content-types.properties file contained the default MIME content-types table used to map content type to file extension, etc, and is used primarily by the URLConnection API. The lib/content-types.properties file was never intended to be user editable. Instead there is a system property, content.types.user.table, that allows one to define their own content types.

See JDK-8039362, for further details on the use of content.types.user.table.

Previous JDK releases documented how to configure java.net.InetAddress to use the JNDI DNS service provider as the name service. This mechanism, and the system properties to configure it, have been removed in JDK 9.

A new mechanism to configure the use of a hosts file has been introduced.

A new system property jdk.net.hosts.file has been defined. When this system property is set, the name and address resolution calls of InetAddress, i.e getByXXX, retrieve the relevant mapping from the specified file. The structure of this file is equivalent to that of the /etc/hosts file.

When the system property jdk.net.hosts.file is set, and the specified file doesn't exist, the name or address lookup will result in an UnknownHostException. Thus, a non existent hosts file is handled as if the file is empty.

The poll based SelectorProvider sun.nio.ch.PollSelectorProvider has been removed in JDK 9. It has been superseded for several releases by improved or higher performance implementations on all supported platforms.

The mechanism of proxying RMI requests through HTTP, which was deprecated in Java SE 8, has been removed in Java SE 9. This mechanism used a web CGI script called java-rmi.cgi. This script has also been removed. The default mechanism for transmitting RMI requests is now simply a direct socket connection.

The deprecated addPropertyListener and removePropertyListener methods have been removed from java.util.jar.Pack200.Packer and java.util.jar.Pack200.Unpacker. Applications that need to monitor progress of a packer or unpacker should poll the value of the PROGRESS property instead.

The zip library implementation has been improved in JDK 9. The new java.util.zip.ZipFile implementation does not use mmap to map ZIP file central directory into memory anymore. As a result, the sun.zip.disableMemoryMapping system property is no longer needed and has been removed.

The deprecated addPropertyListener and removePropertyListener methods have been removed from java.util.logging.LogManager. Code that relies on a listener to be invoked when logging configuration changes should use the new addConfigurationListener and removeConfigurationListener methods instead.

javax.naming.Context.APPLET has been deprecated. If the environment specified when creating an InitialContext contains Context.APPLET then it is ignored. Applets with JNDI configuration in applet parameters should use the Applet.getParameter(String) method to read the parameters and use the values to create the JNDI context.

The possibility to provide provide subclasses of jdk.nashorn.internal.runtime.CodeStore through the java.util.ServiceLoader API has been removed in JDK 9.

The methods monitorEnter, monitorExit and tryMonitorEnter on sun.misc.Unsafe are removed in JDK 9. These methods are not used within the JDK itself and are very rarely used outside of the JDK.

The following unsupported APIs are removed:

• com.sun.tracing
• com.sun.tracing.dtrace

The Serviceability Agent (SA) Core and PID debugger Connectors have been removed in this release. It is no longer possible to use a Java Debugger to attach to a core file or process with the SA mechanism.

The JMX RMIConnector only supports the JRMP transport in JDK 9. Support for the optional IIOP transport has been removed in this release.

native2ascii tool is removed in JDK 9. JDK 9 supports UTF-8 based properties resource bundles (see JEP 226 and the conversion for UTF-8 based properties resource bundles to ISO-8859-1 is no longer needed.

management-agent.jar has been removed. Tools that have been using the Attach API to load this agent into a running VM should be aware that the Attach API has been updated in JDK 9 to define two new methods for starting a management agent:

• com.sun.tools.attach.VirtualMachine.startManagementAgent(Properties agentProperties)
• com.sun.tools.attach.VirtualMachine.startLocalManagementAgent()

The experimental/unsupported jhat tool has been removed.

The serialver -show option has been removed in this release.

The extcheck tool has been removed in this release.

The experimental rmic -Xnew option has been disabled for this release.

Support for serialized applets has been removed. The "OBJECT" attribute of the <APPLET> tag and "object" and "java_object" applet parameter tags will no longer be recognized during applet launching, and will be ignored.

The -XX:SafepointPollOffset flag has been removed because it was introduced only to reproduce a problem with the C1 compiler and is no longer needed.

The -XX:BackEdgeThreshold flag has been removed because it is no longer supported. Users now need to use -XX:OnStackReplacePercentage instead.

The -XX:EnableInvokeDynamic flag has been removed because the VM does no longer support execution without invokedynamic.

The -XX:+Use486InstrsOnly flag has been removed because it is no longer supported.

Per-thread compiler performance counters have been removed because they became obsolete in the presence of more fine-grained and precise compilation events. The corresponding interface in sun.management.* has been deprecated since it will no longer provide information without the performance counters. Users can get similar or more fine-grained information via global performance counters, the event tracing API (JFR) or -XX:+PrintCompilation.

These internal command line flags, which have been deprecated or aliased since JDK 6, have been removed:

CMSParPromoteBlocksToClaim, ParCMSPromoteBlocksToClaim, ParallelGCOldGenAllocBufferSize, ParallelGCToSpaceAllocBufferSize, UseGCTimeLimit, CMSPermGenSweepingEnabled, ResizeTLE, PrintTLE, TLESize, UseTLE, MaxTLERatio, TLEFragmentationRatio, TLEThreadRatio

In addition to this, these internal flags have been deprecated:

CMSMarkStackSizeMax, ParallelMarkingThreads, ParallelCMSThreads, CMSMarkStackSize, G1MarkStackSize

The GC combinations that were deprecated in JDK 8 have now been removed. This means that the following GC combinations no longer exist:

• DefNew + CMS
• ParNew + SerialOld
• Incremental CMS The "foreground" mode for CMS has also been removed.

The command line flags that were removed are: -Xincgc, -XX:+CMSIncrementalMode, -XX:+UseCMSCompactAtFullCollection, -XX:+CMSFullGCsBeforeCompaction and -XX:+UseCMSCollectionPassing.

The command line flag -XX:+UseParNewGC no longer has any effect. ParNew can only be used with CMS and CMS requires ParNew. Thus, the -XX:+UseParNewGC flag has been deprecated and will likely be removed in a future release.

The VM Options -XX:AdjustConcurrency and -XX:PrintJVMWarnings are removed from JDK 9.

The VM option -XX:AdjustConcurrency was only needed on Solaris 8/9 (when using the T1 threading library).

The VM option -XX:PrintJVMWarnings was a development option only used by unimplemented VM functions that have themselves been removed in JDK 9.

On Oracle Solaris, the JDK and JRE no longer have an ISA (Instruction Specific Architecture) bin directory. The $JAVA_HOME/bin/sparcv9 and $JAVA_HOME/bin/amd64 directories, and the sym links in the directories, were present in JDK 8 to aid migration after 32-bit support was removed. Scripts or applications that rely on these locations should be updated to use $JAVA_HOME/bin.

The lib/$ARCH directory, which used to contain native-code shared objects (.so files) for the VM and the libraries, has been removed and the contents has moved up one level into the lib/ directory.

Several deprecated and undocumented "impl_*" methods have been removed from JDK 9.

In prior releases, many public JavaFX classes in exported packages had public or protected implementation methods that were named with "impl_*" in the name, marked as "@Deprecated" with the stated intention of removing them, and hidden from the API documentation with the "@treatAsPrivate" javadoc tag.

These methods were never supported and were not intended to be used by applications. JavaFX applications that were using these undocumented methods will need to stop calling them.

The JavaFX builder classes, which were previously deprecated in JDK 8 with the stated intention to remove them, have been removed from JDK 9. JavaFX applications that use the builder classes should instead construct the needed scene graph objects directly and set the desired properties with the equivalent method calls.

The com.apple.concurrent.Dispatch API was a Mac-only API and was carried into JDK 7u4 with the port of Apple's JDK 6 code. This seldom-used and unsupported API has been removed in JDK 9. Developers are encouraged to use the standard java.util.concurrent.Executor and java.util.concurrent.ExecutorService APIs instead.

The AppleScript engine implementing javax.script engine API has been removed without replacement. The AppleScript engine has worked inconsistently. The services configuration (META-INF/services) file was missing and only worked by accident when installing JDK 7 or JDK 8 on systems that had Apple's version of AppleScriptEngine.jar already on the system.

The JDK-specific annotation @jdk.Exported has been removed in JDK 9. The information that @jdk.Exported conveyed is now recorded in the exports declarations of modules. Tools that scan for this annotation should be updated to make use of the new API support in javax.lang.model and java.lang.module.

The javax.crypto.ExemptionMechanism.finalize() method has been removed from both the specification and the implementation.

The com.sun.security.auth.callback.DialogCallbackHandler class has been removed. This class, which is in the JDK-specific extensions to JAAS, was deprecated in JDK 8 and previously flagged for removal.

The Launch-Time JRE Version Selection also known as Multiple JRE or mJRE functionality will no longer be available with the java launcher. This means the java launcher will not invoke another JRE version, and will exit with an error.

The presence of "-version:x.y.z", "-jre-restrict-search" and "-jre-no-restrict-search" on the java launcher's command-line will cause it to exit with an error message. The environment variable "JRE_VERSION_PATH" will be ignored.

The Java Archive (jar) manifest entry "JRE-version" will cause the java launcher to emit a warning, and "JRE-Restrict-Search" will be ignored.

Visual VM is a tool that provides information about code running on a Java Virtual Machine. It was provided with Oracle JDK 6, Oracle JDK 7, and Oracle JDK 8.

Starting from JDK 9, the tool (jvisualvm) is no longer included in Oracle JDK. Users can still download the tool from the official project website at https://visualvm.github.io