In JDK 8, a new command-line tool, jdeps, is added that developers can use to understand the static dependencies of their applications and libraries. It also provides an -jdkinternals option to find dependencies to any JDK internal APIs that are unsupported and private to JDK implementation (see Why Developers Should Not Write Programs That Call 'sun' Packages).
Simple way to run jdeps to find out if your library/application depends on any JDK internal API:
$ jdeps -dotoutput <dot-file-dir> -jdkinternals <one-or-more-jar-files....>
This jdeps command will output the dependencies in DOT file format and one output .dot file per JAR file.
See the jdeps man page for more information. jdeps is a static analysis tool on the given class files and dynamic class dependencies (Class.forName or loading of service providers etc) are not reported.
Below lists some of the JDK internal APIs and the recommended way to replace their usage.
| Component | Unsupported API (not for use) | Supported APIs (please use instead) | Note |
|---|---|---|---|
| core-libs | sun.io | java.nio.charsets @since 1.4 | |
sun.misc.BASE64Decoder, sun.misc.BASE64Encoder, | java.util.Base64 @since 8 | See http://openjdk.java.net/jeps/135 | |
| sun.misc.ClassLoaderUtil | java.net.URLClassLoader.close() @since 7 | ||
| sun.misc.Cleaner | java.lang.ref.PhantomReference @since 1.2 | ||
| sun.misc.Service | java.util.ServiceLoader @since 1.6 | ||
| sun.misc.Timer | java.util.Timer @since 1.3 | ||
| sun.misc.Unsafe | sun.misc.Unsafe consists of a number of use cases. The following features are identified to provide support in the future releases:
| ||
| sun.reflect.Reflection.getCallerClass | TBD | A JEP will be submitted to define a supported API | |
| security-libs | sun.security.action.* | java.security.PrivilegedAction to call System.getProperty or other action @since 1.1 | AccessController.doPrivileged( |
| sun.security.krb5.* | Some provided in com.sun.security.jgss | If internal classes are used to get the session key of Krb5Context, we now have ExtendedGSSContext for this purpose. | |
| sun.security.util.SecurityConstants | java.lang.RuntimePermission, java.net.NetPermission, or specific Permission class @since 1.1 | ||
| sun.security.x509.X500Name | javax.security.auth.x500.X500Principal @since 1.4 | ||
| com.sun.org.apache.xml.internal.security | javax.xml.crypto @since 1.6 | ||
com.sun.net.ssl.** | javax.net.ssl @since 1.4 | ||
security provider implementation class such as
| java.security.Security.getProvider("SUN") @sine 1.3 | In general, you should avoid depending on a specific provider as it may not be available on other Java implementations. See Oracle security providers documentation for more rationale. | |
| sun.security.provider.PolicyFile() or sun.security.provider.PolicyFile(URL) | java.security.Policy.getInstance("JavaPolicy", new java.security.URIParameter(uri)); @since 1.6 | ||
| client-libs | java.awt.peer and java.awt.dnd.peer | TBD (JDK-8037739) | The AWT Peer API has been unsupported API and java.awt.peer.ComponentPeer interface depends on sun.* internal API. |
com.sun.image.codec.jpeg.** sun.awt.image.codec | javax.imageio @since 1.4 | See JDK-6527962 | |
| jdbc | com.sun.rowset.** | javax.sql.rowset.RowSetProvider @since 7 | |
| compiler | com.sun.tools.javac.** | javax.tools, javax.lang.model @since 1.6 com.sun.source | com.sun.tools.javac.Main is a supported API. |
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