File	Doc	Category	Size	Date	Package
ConcatFilter.java	API Doc	Apache Ant 1.70	6659	Wed Dec 13 06:16:22 GMT 2006	org.apache.tools.ant.filters

ConcatFilter

• java.lang.Object
  • BaseParamFilterReader

Fields Summary
private File	prepend File to add before the content.
private File	append File to add after the content.
private Reader	prependReader Reader for prepend-file.
private Reader	appendReader Reader for append-file.

Constructors Summary
public ConcatFilter() Constructor for "dummy" instances. see BaseFilterReader#BaseFilterReader() super();
public ConcatFilter(Reader in) Creates a new filtered reader. param in A Reader object providing the underlying stream. Must not be null. super(in);

Methods Summary
public java.io.Reader	chain(java.io.Reader rdr) Creates a new ConcatReader using the passed in Reader for instantiation. param rdr A Reader object providing the underlying stream. Must not be null. return a new filter based on this configuration, but filtering the specified reader ConcatFilter newFilter = new ConcatFilter(rdr); newFilter.setPrepend(getPrepend()); newFilter.setAppend(getAppend()); // Usually the initialized is set to true. But here it must not. // Because the prepend and append readers have to be instantiated // on runtime //newFilter.setInitialized(true); return newFilter;
public java.io.File	getAppend() Returns append attribute. return append attribute return append;
public java.io.File	getPrepend() Returns prepend attribute. return prepend attribute return prepend;
private void	initialize() Scans the parameters list for the "lines" parameter and uses it to set the number of lines to be returned in the filtered stream. also scan for skip parameter. // get parameters Parameter[] params = getParameters(); if (params != null) { for (int i = 0; i < params.length; i++) { if ("prepend".equals(params[i].getName())) { setPrepend(new File(params[i].getValue())); continue; } if ("append".equals(params[i].getName())) { setAppend(new File(params[i].getValue())); continue; } } } if (prepend != null) { if (!prepend.isAbsolute()) { prepend = new File(getProject().getBaseDir(), prepend.getPath()); } prependReader = new BufferedReader(new FileReader(prepend)); } if (append != null) { if (!append.isAbsolute()) { append = new File(getProject().getBaseDir(), append.getPath()); } appendReader = new BufferedReader(new FileReader(append)); }
public int	read() Returns the next character in the filtered stream. If the desired number of lines have already been read, the resulting stream is effectively at an end. Otherwise, the next character from the underlying stream is read and returned. return the next character in the resulting stream, or -1 if the end of the resulting stream has been reached exception IOException if the underlying stream throws an IOException during reading // do the "singleton" initialization if (!getInitialized()) { initialize(); setInitialized(true); } int ch = -1; // The readers return -1 if they end. So simply read the "prepend" // after that the "content" and at the end the "append" file. if (prependReader != null) { ch = prependReader.read(); if (ch == -1) { // I am the only one so I have to close the reader prependReader.close(); prependReader = null; } } if (ch == -1) { ch = super.read(); } if (ch == -1) { // don't call super.close() because that reader is used // on other places ... if (appendReader != null) { ch = appendReader.read(); if (ch == -1) { // I am the only one so I have to close the reader appendReader.close(); appendReader = null; } } } return ch;
public void	setAppend(java.io.File append) Sets append attribute. param append new value this.append = append;
public void	setPrepend(java.io.File prepend) Sets prepend attribute. param prepend new value this.prepend = prepend;