Interface IJavaComponent


public interface IJavaComponent
Client interface of a Java component. I.e. any Java component provides an implementation of this interface when looked up.

A Java component is declared by using the component type com.zfabrik.java (see also IComponentDescriptor.COMPONENT_TYPE)

Java components generally serve Java type definitions to other components, for example Web applications.

One important defaulting mechanism applies to Java components: By convention, other component types that require or support an implementation, for example a Web application will use JavaComponentUtil to identify a Java component that is used to load types from. Given a project com.acme.myproject, the default Java component to look for is com.acme.myproject/java, i.e. the project name with an appended "/java". Components within the project use the private loader of that Java component by convention.

See also IComponentsRepository for a typical component repository layout.

In most cases Java components do hold Java resources, e.g. Java source files or JAR libraries. In some cases all types required are provided elsewhere, so that the project itself does not hold any Java resources. In that case a Java component does not require a folder structure but may be specified only a set of properties defining references to other Java components.

The folder structure of Java components assigns meaning to the following files and folders:

z.properties
The component descriptor. Typically this looks like
 com.zfabrik.component.type=com.zfabrik.java
 java.publicReferences=<java component 1>, <java component 2>,...
 java.privateReferences=<java component n>, <java component n+1>,...
 
src.api
Public type definitions that will be compiled and exposed so that they are visible by other Java components. See PUBREFS.
bin.api/lib
JAR libraries to be added to the public types of the Java Component.
bin.api/classes
Pre-compiled Java code, i.e. .class files and other resources to be added to the public types of the Java Component.
src.impl
Type definitions that will be compiled and made available for use within the project (see above) but will not be exposed to other Java components. See PRIREFS.
bin.impl/lib
JAR libraries to be added to the private types of the Java Component.
bin.impl/classes
Pre-compiled Java code, i.e. .class files and other resources to be added to the private types of the Java Component.
src.test
Type definitions that will be compiled and made available for use just like the types defined in src.impl. In contrast to src.impl, the source files in src.test will be ignored unless the runtime runs in development mode, that is the system property Foundation.MODE is set to "development".
bin.test/lib
JAR libraries to be added to the private types of the Java Component iff running in development mode.
bin.test/classes
Pre-compiled Java code, i.e. .class files and other resources to be added to the private types of the Java Component iff running in development mode.

Java components may "include" components of type com.zfabrik.files. This can be useful for libraries that cannot be shared by just re-using the classes but instead require to be used within the using component's context, e.g. to load classes by name that would not be within the library's scope. This is true for older versions of the Spring framework for example.

Files components may be included as API or impl provisioning depending on the reference used. The included source files or pre-compiled binaries are expected to comply to the following folder structure:

src
Source files that require compilation before execution.
bin/lib
JAR libraries
bin/classes
Pre-compiled Java code, i.e. .class files and other resources

The following properties can be used in the component descriptor:

java.publicReferences
Points to other java components whose types will be shared with this one (and maybe others).

Everything referenced as public reference will be visible to the public interface of the referencing component as well as to all referencing the referencing component. In other words: References are transitive. In particular, anything required to compile the public types of a Java component must be referenced via this reference property.

Components may be specified as a comma-separated list. Component names that have no "/" will be defaulted by appending "/java".

Alternatively this reference points to a com.zfabrik.files component that must have a bin folder that will be included into this java component's java resources. The files resource may also have a src folder that will be copied befor compilation into the public interface in src.api or src.

See also JavaComponentUtil.fixJavaComponentName(String)

java.privateReferences
Points to other java components whose types will be shared with this one (and maybe others) Nothing referenced as private reference will be automatically exposed to the public interface of the referencing component nor to other components. Anything needed to compile the private types of a Java component, must be referenced as a public reference, be part of the public types of that component, or be referenced via this reference property.
In other words: The private types automatically see the public types and transitively anything referenced publicly as described above. In addition, to use more types in the "private implementation section" of a Java component, types that will not be exposed to referencing components, use this reference property.

Components may be specified as a comma-separated list. Component names that have no "/" will be defaulted by appending "/java".

Alternatively this reference points to a com.zfabrik.files component that must have a bin folder that will be included into this java component's java resources. The files resource may also have a src folder that will be copied befor compilation into the public interface in src.impl or private/src.

See also JavaComponentUtil.fixJavaComponentName(String)

java.testReferences
When running in development mode, the test references add to the private references of the component. Test references are meant to satisfy the dependencies of types and other definitions defined in src.test, bin.test. When not running in development mode, this setting will be ignored.
java.nobuild
A Java component specifying true as the value of this component property will be ignored by the compilation mechanism (as it will be in javadoc generation).
java.compile.order
The compile order must be defined in java components that also contain non-java sources, e.g. scala, or require special handling like apsect weaving. This property can be omitted for pure java components, otherwise one has to define all compilers in the right order - e.g: scala, java
Author:
hb
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static enum 
    A Java component is constructed from three different aspects, that are either publicly shared, privately used for implementation, or only available in development mode for testing.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    The compile order must be defined in java components that also contain non-java sources e.g.
    static final String
    Default inclusion pattern for classpath computation of the component.
    static final String
    A Java component specifying true as the value of this component property will be ignored by the compilation mechanism (as it will be in javadoc generation).
    static final String
    Points to com.zfabrik.files or com.zfabrik.java components that must have a bin (or alternatively a bin.api, for Java components) folder that will be included into this java component's private java resources.
    static final String
    Points to another java component whose public types will be shared with this one (and maybe others) Nothing referenced as private reference will be automatically exposed to the public interface of the referencing component nor to other components.
    static final String
    Custom inclusion pattern for classpath computation of the impl section.
    static final String
    Specific override of compile order for the implementation part of a Java component.
    static final String
    Points to com.zfabrik.files or com.zfabrik.java components that must have a bin (or alternatively a bin.api, for Java components) folder that will be included into this java component's public java resources.
    static final String
    Custom inclusion pattern for classpath computation of the API section.
    static final String
    Specific override of compile order for the API part of a Java component.
    static final String
    Points to another java component whose public types will be shared with this one (and maybe others).
    static final String
    Custom inclusion pattern for classpath computation of the test section.
    static final String
    Specific override of compile order for the test part of a Java component.
    static final String
    Points to com.zfabrik.files or com.zfabrik.java components that must have a bin (or alternatively a bin.api, for Java components) folder that will be included into this java component's test java resources.
    static final String
    Points to another java component whose public types will be shared with this one (and maybe others) if the execution mode, as defined by the system property (see also Foundation.MODE) is set to "development".
    static final String
    Type constant for Java components.
  • Method Summary

    Modifier and Type
    Method
    Description
    Retrieve the private implementation's loader of this Java component.
    Retrieve the public interface's loader of this Java component.
    Unlike the originally provided Java component repository resources made accessible via IComponentsRepository.retrieve(String), due to compilation the runtime resources are the result of one or more compilation operations.
  • Field Details

    • TYPE

      static final String TYPE
      Type constant for Java components.
      See Also:
    • PUBREFS

      static final String PUBREFS
      Points to another java component whose public types will be shared with this one (and maybe others).

      Everything referenced as public reference will be visible to the public interface of the referencing component as well as to all referencing the referencing component. In other words: References are transitive. In particular, anything required to compile the public types of a Java component must be referenced via this reference property.

      Components may be specified as a comma-separated list. Component names that have no "/" will be defaulted by appending "/java".

      See Also:
    • PUBINCS

      static final String PUBINCS
      Points to com.zfabrik.files or com.zfabrik.java components that must have a bin (or alternatively a bin.api, for Java components) folder that will be included into this java component's public java resources. The component may also have a src (or alternatively src.api, for Java components) folder that will be copied before compilation into src.api.
      See Also:
    • PRIREFS

      static final String PRIREFS
      Points to another java component whose public types will be shared with this one (and maybe others) Nothing referenced as private reference will be automatically exposed to the public interface of the referencing component nor to other components. Anything needed to compile the private types of a Java component, must be referenced as a public reference, be part of the public types of that component, or be referenced via this reference property.
      In other words: The private types automatically see the public types and transitively anything referenced publicly as described above. In addition, to use more types in the "private implementation section" of a Java component, types that will not be exposed to referencing components, use this reference property.

      Components may be specified as a comma-separated list. Component names that have no "/" will be defaulted by appending "/java".

      See Also:
    • PRIINCS

      static final String PRIINCS
      Points to com.zfabrik.files or com.zfabrik.java components that must have a bin (or alternatively a bin.api, for Java components) folder that will be included into this java component's private java resources. The component may also have a src (or alternatively src.api, for Java components) folder that will be copied before compilation into src.impl.
      See Also:
    • TESTREFS

      static final String TESTREFS
      Points to another java component whose public types will be shared with this one (and maybe others) if the execution mode, as defined by the system property (see also Foundation.MODE) is set to "development". Test references extend the private references. In conjunction with the tests source folder this allows to add test code and corresponding dependencies that will be ignored by the runtime unless running in development mode.

      See also PRIREFS

      See Also:
    • TESTINCS

      static final String TESTINCS
      Points to com.zfabrik.files or com.zfabrik.java components that must have a bin (or alternatively a bin.api, for Java components) folder that will be included into this java component's test java resources. The component may also have a src (or alternatively src.api, for Java components) folder that will be copied before compilation into src.test.
      See Also:
    • NOBUILD

      static final String NOBUILD
      A Java component specifying true as the value of this component property will be ignored by the compilation mechanism (as it will be in javadoc generation).
      See Also:
    • COMPILE_ORDER

      static final String COMPILE_ORDER
      The compile order must be defined in java components that also contain non-java sources e.g. scala code or that require additional handling by e.g. aspect weaving. Z2 offers a compiler extension mechanism for that purpose. This property defines the order in which compilers will be applied. This property can be omitted for pure java components in that it defaults to java. Otherwise one has to define all compilers in the right order - e.g: scala, java
      See Also:
    • PUBLIC_COMPILE_ORDER

      static final String PUBLIC_COMPILE_ORDER
      Specific override of compile order for the API part of a Java component. Otherwise like COMPILE_ORDER.
      See Also:
    • PRIVATE_COMPILE_ORDER

      static final String PRIVATE_COMPILE_ORDER
      Specific override of compile order for the implementation part of a Java component. Otherwise like COMPILE_ORDER.
      See Also:
    • TEST_COMPILE_ORDER

      static final String TEST_COMPILE_ORDER
      Specific override of compile order for the test part of a Java component. Otherwise like COMPILE_ORDER.
      See Also:
    • DEFAULT_CLASSPATH_PATTERN

      static final String DEFAULT_CLASSPATH_PATTERN
      Default inclusion pattern for classpath computation of the component. Only library files matching this pattern will be included into classpath computation by default. This has no effect on the inclusion of .class files.
      See Also:
    • PUBLIC_CLASSPATH_PATTERN

      static final String PUBLIC_CLASSPATH_PATTERN
      Custom inclusion pattern for classpath computation of the API section. Only library files matching the specified pattern will be included into the respective classpath computation. This has no effect on the inclusion of .class files.
      See Also:
    • PRIVATE_CLASSPATH_PATTERN

      static final String PRIVATE_CLASSPATH_PATTERN
      Custom inclusion pattern for classpath computation of the impl section. Only library files matching the specified pattern will be included into the respective classpath computation. This has no effect on the inclusion of .class files.
      See Also:
    • TEST_CLASSPATH_PATTERN

      static final String TEST_CLASSPATH_PATTERN
      Custom inclusion pattern for classpath computation of the test section. Only library files matching the specified pattern will be included into the respective classpath computation. This has no effect on the inclusion of .class files.
      See Also:
  • Method Details

    • getPrivateLoader

      JavaComponentClassLoader getPrivateLoader()
      Retrieve the private implementation's loader of this Java component. When this call completes, the Java component will have been checked and possibly compiled, if needed.
    • getPublicLoader

      JavaComponentClassLoader getPublicLoader()
      Retrieve the public interface's loader of this Java component. When this call completes, the Java component will have been checked and possibly compiled, if needed.
    • getRuntimeResources

      File getRuntimeResources()
      Unlike the originally provided Java component repository resources made accessible via IComponentsRepository.retrieve(String), due to compilation the runtime resources are the result of one or more compilation operations. Initially the runtime resources are set as the originally provided resources. Compilation processes may alter these resources as required. The standard Java compilation process only adds compilation results, actual .jar files and does not modify other resources.

      Due to changes in dependency components, compilation processes might be run more than once per actual Java component revision and different runtime instances of z2 may access different runtime resources while sharing one set of repository resources.

      This method provides access to the runtime resources root.