Resolve JRE version late

nebhale · nebhale · commit 26031c07af4b · 2014-03-24T11:26:27.000Z
Previously when detect() was called on the buildpack, it would resolve
a version of the JRE, regardless of whether the application was a Java
application or not.  This meant that any network connectivity problems
that might be highlighted by the Java buildpack would show in non-Java
projects.

An ideal solution to this would be to change the implementation of the
VersionedDependcyComponent such that version and uri resolution
happened as part of detect, but this would break compatibility for
many 3rd-party components. Instead, that resolution is moved to
detect, *but only for OpenJDK- like JREs*.  This leads to the
replication of some of the initialization code, but this is considered
a less-bad solution than breaking compatibility.

The end result is that the version and uri of
VersionedDependencyComponents will happen at initialization time, and
be avoided by inspections of the filesystem.  The JRE will not resolve
as part of initialization, but rather at detect time.

[#67329858]
diff --git a/java-buildpack.iml b/java-buildpack.iml
@@ -288,7 +288,7 @@
     <orderEntry type="library" scope="PROVIDED" name="rspec-expectations (v3.0.0.beta2, rbenv: 1.9.3-p545) [gem]" level="application" />
     <orderEntry type="library" scope="PROVIDED" name="rspec-mocks (v3.0.0.beta2, rbenv: 1.9.3-p545) [gem]" level="application" />
     <orderEntry type="library" scope="PROVIDED" name="rspec-support (v3.0.0.beta2, rbenv: 1.9.3-p545) [gem]" level="application" />
-    <orderEntry type="library" scope="PROVIDED" name="rubocop (v0.19.0, rbenv: 1.9.3-p545) [gem]" level="application" />
+    <orderEntry type="library" scope="PROVIDED" name="rubocop (v0.19.1, rbenv: 1.9.3-p545) [gem]" level="application" />
     <orderEntry type="library" scope="PROVIDED" name="ruby-debug-base19x (v0.11.30.pre15, rbenv: 1.9.3-p545) [gem]" level="application" />
     <orderEntry type="library" scope="PROVIDED" name="ruby-debug-ide (v0.4.22, rbenv: 1.9.3-p545) [gem]" level="application" />
     <orderEntry type="library" scope="PROVIDED" name="ruby-progressbar (v1.4.2, rbenv: 1.9.3-p545) [gem]" level="application" />
diff --git a/lib/java_buildpack/jre/open_jdk_like.rb b/lib/java_buildpack/jre/open_jdk_like.rb
@@ -29,10 +29,20 @@ class OpenJDKLike < JavaBuildpack::Component::VersionedDependencyComponent
       #
       # @param [Hash] context a collection of utilities used the component
       def initialize(context)
-        super(context)
+        @application    = context[:application]
+        @component_name = self.class.to_s.space_case
+        @configuration  = context[:configuration]
+        @droplet        = context[:droplet]
+
         @droplet.java_home.root = @droplet.sandbox
       end
 
+      # (see JavaBuildpack::Component::BaseComponent#detect)
+      def detect
+        @version, @uri = JavaBuildpack::Repository::ConfiguredItem.find_item(@component_name, @configuration)
+        super
+      end
+
       # (see JavaBuildpack::Component::BaseComponent#compile)
       def compile
         download_tar
@@ -47,13 +57,6 @@ def release
         .concat memory
       end
 
-      protected
-
-      # (see JavaBuildpack::Component::VersionedDependencyComponent#supports?)
-      def supports?
-        true
-      end
-
       private
 
       KEY_MEMORY_HEURISTICS = 'memory_heuristics'.freeze
diff --git a/spec/java_buildpack/jre/open_jdk_jre_spec.rb b/spec/java_buildpack/jre/open_jdk_jre_spec.rb
@@ -38,6 +38,7 @@
   it 'should extract Java from a GZipped TAR',
      cache_fixture: 'stub-java.tar.gz' do
 
+    component.detect
     component.compile
 
     expect(sandbox + 'bin/java').to exist
@@ -50,13 +51,15 @@
   end
 
   it 'should add memory options to java_opts' do
+    component.detect
     component.release
 
     expect(java_opts).to include('opt-1')
     expect(java_opts).to include('opt-2')
   end
 
   it 'adds OnOutOfMemoryError to java_opts' do
+    component.detect
     component.release
 
     expect(java_opts).to include('-XX:OnOutOfMemoryError=$PWD/.java-buildpack/open_jdk_jre/bin/killjava.sh')
@@ -65,12 +68,14 @@
   it 'places the killjava script (with appropriately substituted content) in the diagnostics directory',
      cache_fixture: 'stub-java.tar.gz' do
 
+    component.detect
     component.compile
 
     expect(sandbox + 'bin/killjava.sh').to exist
   end
 
   it 'adds java.io.tmpdir to java_opts' do
+    component.detect
     component.release
 
     expect(java_opts).to include('-Djava.io.tmpdir=$TMPDIR')
diff --git a/spec/java_buildpack/jre/oracle_jre_spec.rb b/spec/java_buildpack/jre/oracle_jre_spec.rb
@@ -38,6 +38,7 @@
   it 'should extract Java from a GZipped TAR',
      cache_fixture: 'stub-java.tar.gz' do
 
+    component.detect
     component.compile
 
     expect(sandbox + 'bin/java').to exist
@@ -50,13 +51,15 @@
   end
 
   it 'should add memory options to java_opts' do
+    component.detect
     component.release
 
     expect(java_opts).to include('opt-1')
     expect(java_opts).to include('opt-2')
   end
 
   it 'adds OnOutOfMemoryError to java_opts' do
+    component.detect
     component.release
 
     expect(java_opts).to include('-XX:OnOutOfMemoryError=$PWD/.java-buildpack/oracle_jre/bin/killjava.sh')
@@ -65,12 +68,14 @@
   it 'places the killjava script (with appropriately substituted content) in the diagnostics directory',
      cache_fixture: 'stub-java.tar.gz' do
 
+    component.detect
     component.compile
 
     expect(sandbox + 'bin/killjava.sh').to exist
   end
 
   it 'adds java.io.tmpdir to java_opts' do
+    component.detect
     component.release
 
     expect(java_opts).to include('-Djava.io.tmpdir=$TMPDIR')
