ServiceLoader in the JDK

[Paul Sandoz]

Hi,

Here is some proposed changes in the JDK related to service loader (not tested yet! just want some easily feedback):

  http://cr.openjdk.java.net/~psandoz/jigsaw/jdk-services/webrev/

I have attempted where possible to tidy things up to avoid an explicit reference to a class loader for common patterns hence the addition of the methods ServiceLoader.loadFromClass, ServiceLoader.loadFromSystem and ServiceLoader.loadFromCaller (when in module mode most ServiceLoader.load* method do the equivalent of the latter). The names could be better.

I also improved the dump-config to output local service provides and remote service suppliers (see below for an example).


Questionable areas:

- I left JMX alone. It is doing lots of funky stuff. Plus will likely require spec changes.

- com.sun.tools.jdi.VirtualMachineManagerImpl is loading providers (Connector and TransportService) from the class loader of those classes. This is probably not an issue. But i do wonder if it could be replaced with ServiceLoader.loadFromCaller().

- sun.tools.jconsole.JConsole uses a URL class loader (with a plugin path) from which services are loaded. I suppose one solution here would be something like:

  if (Platform.isModuleMode()) {
    // Use ServiceLoader.loadFromCaller(JConsolePlugin.class) and ignore the plugin path
  } else {
    // code as before
  } 

Does the "jconsole -pluginpath " option make much sense on module mode?  Although in general I presume a URLClassLoader could be used like this in module mode (i have not verified). Perhaps we require a -L <module library path> option.

Paul.

ServiceTest $ jmod -L build/mlib dump-config mfoo
configuration roots = [mfoo at 1.0]
  context +jdk.logging
    module jdk.logging at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.logging at 8-ea
    local (79) ...
    remote (74)
  context +mfoo
    module mfoo at 1.0
      view mfoo at 1.0
    local service providers (1)
      com.sun.net.httpserver.spi.HttpServerProvider
        foo.HP
    local (3)
      foo.Foo:mfoo at 1.0
      foo.HP:mfoo at 1.0
      foo.HP$1:mfoo at 1.0
    remote (48)
  context +jdk.httpserver
    module jdk.httpserver at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.httpserver at 8-ea
    remote service suppliers (1)
      com.sun.net.httpserver.spi.HttpServerProvider
        +mfoo
    local (69) ...
    remote (51)
  context +jdk.jaxp
    module jdk.jaxp at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.jaxp at 8-ea
      view jdk.jaxp.internal at 8-ea
    local (2335) ...
    remote (46)
  context +jdk.rmi
    module jdk.rmi at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.rmid at 8-ea
      view jdk.rmi.internal at 8-ea
      view jdk.rmiregistry at 8-ea
      view jdk.rmi at 8-ea
    local (243) ...
    remote (79)
  context +jdk.auth+jdk.base+jdk.desktop+jdk.jndi+jdk.prefs+jdk.tls+sun.charsets+sun.localedata
    module sun.localedata at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view sun.localedata at 8-ea
    module jdk.tls at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.tls.internal at 8-ea
      view jdk.tls at 8-ea
    module jdk.base at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.base at 8-ea
      view jdk.base.unsafe at 8-ea
      view jdk.base.internal at 8-ea
      view jdk.base.oracle at 8-ea
      view jdk.jmod at 8-ea
    module sun.charsets at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view sun.charsets.internal at 8-ea
      view sun.charsets at 8-ea
    module jdk.prefs at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.prefs at 8-ea
    module jdk.jndi at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.jndi.internal at 8-ea
      view jdk.jndi at 8-ea
    module jdk.auth at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.auth.internal at 8-ea
      view jdk.auth at 8-ea
    module jdk.desktop at 8-ea [/Users/sandoz/Projects/jdk8/jigsaw/build/macosx-x86_64/lib/modules]
      view jdk.desktop at 8-ea
      view jdk.desktop.internal at 8-ea
    local service providers (6)
      sun.net.spi.nameservice.NameServiceDescriptor
        sun.net.spi.nameservice.dns.DNSNameServiceDescriptor
      javax.print.PrintServiceLookup
        sun.print.UnixPrintServiceLookup
      sun.java2d.cmm.PCMM
        sun.java2d.cmm.lcms.LCMS
      javax.print.StreamPrintServiceFactory
        sun.print.PSStreamPrinterFactory
      sun.java2d.pipe.RenderingEngine
        sun.java2d.jules.JulesRenderingEngine
        sun.java2d.pisces.PiscesRenderingEngine
      java.nio.charset.spi.CharsetProvider
        sun.nio.cs.ext.ExtendedCharsets
    local (10920) ...
    remote (46)