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There
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are
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four
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ways
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of
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creating
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a
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BI
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Component:
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create
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a
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BI
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Component
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from
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scratch,
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convert
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an
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existing
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class
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into
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a
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BI
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Component,
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create
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a
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subclass
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of
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ComponentBase
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(org.pentaho.plugin.ComponentBase),
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or
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create
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a
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subclass
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of
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SimpleComponent
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(org.pentaho.plugin.core.SimpleComponent).
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To
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become
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a
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BI
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Component,
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a
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Java
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object
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must
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implement
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the
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org.pentaho.core.component.IComponent
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interface.
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The
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IComponent
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interface
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extends
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two
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other
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interfaces:
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org.pentaho.core.audit.IAuditable
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and
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org.pentaho.util.logging.ILogger.
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Pentaho
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provides
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classes
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that
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implement
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these
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interfaces.
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The
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hierarchy
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of
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the
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Pentaho
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classes
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looks
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like
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this:
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org.pentaho.core.system.PentahoBase
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(implements
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ILogger
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and
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Serializable)
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   -->
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org.pentaho.core.system.PentahoMessenger
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       -->
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org.pentaho.plugin.ComponentBase
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(implements
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IComponent
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and
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IAuditable)
           -->
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org.pentaho.plugin.core.SimpleComponent
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               -->
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other
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Pentaho-provided
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BI
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Components
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You
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can
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create
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your
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BI
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Components
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in
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whatever
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package
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you
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like
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whether
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they
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are
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subclasses
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of
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Pentaho
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classes
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or
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not.
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There
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are
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no
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required
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methods
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that
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will
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be
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inaccessible
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if
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you
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use
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a
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non-Pentaho
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package.
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Extend
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SimpleComponent
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This
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is
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the
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easiest
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way
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to
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create
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a
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new
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component
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and
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the
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recommended
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place
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to
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start.
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- Create
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- a
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- new
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- Java
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- class
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- that
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- is
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- a
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- subclass
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- of
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- (extends)
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- org.pentaho.plugin.core.SimpleComponent.
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- Implement
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- an
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- method
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- and
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- a
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- method.
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- See
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- #Component Methods below for a description of these methods.
Extend ComponentBase
If your component needs to validate its inputs and/or system settings or needs to perform any initialization and/or cleanup, you should extend org.pentaho.plugin.ComponentBase.
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- Create
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- a
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- new
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- Java
...
- class
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- that
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- is
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- a
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- subclass
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- of
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- (extends)
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- org.pentaho.plugin.ComponentBase.
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- Add
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- code
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- to
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- the
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...
- ,
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- ,
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- ,
...
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- ,
...
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- ,
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- and
...
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- methods
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- as
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- appropriate.
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Convert a Java Object into a BI Component
If you have an existing object that you wish to convert into a BI Component there are two options.
Create a new object that subclasses your existing object and implements the required interfaces
Change your object to implement the required interfaces
Which of these options is the best for your particular object will depend on your specific circumstances; but, we recommend creating a subclass if only to keep your source file size manageable.
If you do need to use this approach most of the code you need to create your new class can be found in these classes: org.pentaho.core.system.PentahoBase,
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org.pentaho.core.system.PentahoMessenger,
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and
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org.pentaho.plugin.ComponentBase.
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To
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make
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this
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process
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easier
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we
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have
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created
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a
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class,
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org.pentaho.plugin.ComponentSubclassExample,
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that
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contains
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the
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code
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you
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need.
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To
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convert
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a
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Java
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class
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to
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a
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BI
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Component:
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- Copy
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- the
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- imports,
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- member
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- variables,
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- and
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- methods
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- from
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- org.pentaho.plugin.ComponentSubclassExample
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- into
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- your
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- Java
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- class.
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- Add
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- code
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- to
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- the
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...
- ,
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- ,
...
...
- ,
...
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- ,
...
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- ,
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- and
...
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- methods
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- as
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- appropriate.
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Components from Scratch
In order to create a component from scratch a new class that implements the interface org.pentaho.core.component.IComponent
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must
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be
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created.
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To
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implement
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all
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three
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interfaces
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requires
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about
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30
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methods
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to
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be
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implemented.
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It
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is
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not
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recommended
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to
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use
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this
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option
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and
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there
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should
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be
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no
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need
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to
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do
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this
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given
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the
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options
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above.
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Component Methods
If using one of the three recommended methods for creating new components, the methods below are the BI Component methods that need to be customized to provide your needed functionality. The methods are listed in the order that they are typically called during normal processing. Depending on the option used to create your component, not all of these methods are required. See above sections for more details.
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