org.apache.tools.ant.filters

## Class ExpandProperties

- java.lang.Object
- - java.io.Reader
  - - java.io.FilterReader
    - - org.apache.tools.ant.filters.BaseFilterReader
      - - org.apache.tools.ant.filters.ExpandProperties

- All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable, ChainableReader

      public final class ExpandProperties
      extends BaseFilterReader
      implements ChainableReader

  Expands Ant properties, if any, in the data.

  Example:

      <expandproperties/>

  Or:

      <filterreader
          classname="org.apache.tools.ant.filters.ExpandProperties"/>

- - ### Field Summary

    - ### Fields inherited from class java.io.FilterReader

      `in`

    - ### Fields inherited from class java.io.Reader

      `lock`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `ExpandProperties()` Constructor for "dummy" instances.
    `ExpandProperties(java.io.Reader in)` Creates a new filtered reader.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `add(PropertySet propertySet)` Restrict the expanded properties using a PropertySet.
    `java.io.Reader` | `chain(java.io.Reader rdr)` Creates a new ExpandProperties filter using the passed in Reader for instantiation.
    `int` | `read()` Returns the next character in the filtered stream.

    - ### Methods inherited from class org.apache.tools.ant.filters.BaseFilterReader

      `getInitialized, getProject, read, readFully, readLine, setInitialized, setProject, skip`

    - ### Methods inherited from class java.io.FilterReader

      `close, mark, markSupported, ready, reset`

    - ### Methods inherited from class java.io.Reader

      `read, read`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### ExpandProperties

          public ExpandProperties()

      Constructor for "dummy" instances.
      See Also:
        `BaseFilterReader.BaseFilterReader()`

    - #### ExpandProperties

          public ExpandProperties(java.io.Reader in)

      Creates a new filtered reader.
      Parameters:
        `in` - A Reader object providing the underlying stream. Must not be `null`.

  - ### Method Detail

    - #### add

          public void add(PropertySet propertySet)

      Restrict the expanded properties using a PropertySet.
      Parameters:
        `propertySet` - replacement lookup

    - #### read

          public int read()
                   throws java.io.IOException

      Returns the next character in the filtered stream. The original stream is first read in fully, and the Ant properties are expanded. The results of this expansion are then queued so they can be read character-by-character.
      Overrides:
        `read` in class `java.io.FilterReader`
      Returns:
        the next character in the resulting stream, or -1 if the end of the resulting stream has been reached
      Throws:
        `java.io.IOException` - if the underlying stream throws an IOException during reading

    - #### chain

          public java.io.Reader chain(java.io.Reader rdr)

      Creates a new ExpandProperties filter using the passed in Reader for instantiation.
      Specified by:
        `chain` in interface `ChainableReader`
      Parameters:
        `rdr` - A Reader object providing the underlying stream. Must not be `null`.
      Returns:
        a new filter based on this configuration, but filtering the specified reader