proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/taskdefs/LoadFile.java

/*
 *  The Apache Software License, Version 1.1
 *
 *  Copyright (c) 2001-2002 The Apache Software Foundation.  All rights
 *  reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in
 *  the documentation and/or other materials provided with the
 *  distribution.
 *
 *  3. The end-user documentation included with the redistribution, if
 *  any, must include the following acknowlegement:
 *  "This product includes software developed by the
 *  Apache Software Foundation (http://www.apache.org/)."
 *  Alternately, this acknowlegement may appear in the software itself,
 *  if and wherever such third-party acknowlegements normally appear.
 *
 *  4. The names "The Jakarta Project", "Ant", and "Apache Software
 *  Foundation" must not be used to endorse or promote products derived
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 *
 *  5. Products derived from this software may not be called "Apache"
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 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 *  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *  ====================================================================
 *
 *  This software consists of voluntary contributions made by many
 *  individuals on behalf of the Apache Software Foundation.  For more
 *  information on the Apache Software Foundation, please see
 *  <http://www.apache.org/>.
 */
package org.apache.tools.ant.taskdefs;

import org.apache.tools.ant.Task;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.types.FilterChain;
import org.apache.tools.ant.filters.util.ChainReaderHelper;

import java.io.*;
import java.util.Vector;

/**
 * Load a file into a property
 *
 * @author Steve Loughran
 * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
 * @created 10 December 2001
 */
public final class LoadFile extends Task {

    /**
     * source file, usually null
     */
    private File srcFile = null;

    /**
     * what to do when it goes pear-shaped
     */
    private boolean failOnError = true;

    /**
     * Encoding to use for filenames, defaults to the platform's default
     * encoding.
     */
    private String encoding = null;

    /**
     * name of property
     */
    private String property = null;

    /**
     * Holds FilterChains
     */
    private final Vector filterChains = new Vector();

    /**
     * Encoding to use for filenames, defaults to the platform's default
     * encoding. <p>
     *
     * For a list of possible values see <a href="http://java.sun.com/products/jdk/1.2/docs/guide/internat/encoding.doc.html">
     * http://java.sun.com/products/jdk/1.2/docs/guide/internat/encoding.doc.html
     * </a>.</p>
     *
     * @param encoding The new Encoding value
     */

    public final void setEncoding(final String encoding) {
        this.encoding = encoding;
    }


    /**
     * Sets the Property attribute of the LoadFile object
     *
     * @param property The new Property value
     */
    public final void setProperty(final String property) {
        this.property = property;
    }


    /**
     * Sets the srcfile attribute.
     *
     * @param srcFile The new SrcFile value
     */
    public final void setSrcFile(final File srcFile) {
        this.srcFile = srcFile;
    }


    /**
     * Sets the Failonerror attribute of the LoadFile object
     *
     * @param fail The new Failonerror value
     */
    public final void setFailonerror(final boolean fail) {
        failOnError = fail;
    }


    /**
     * read in a source file to a property
     *
     * @exception BuildException if something goes wrong with the build
     */
    public final void execute()
        throws BuildException {
        //validation
        if (srcFile == null) {
            throw new BuildException("source file not defined");
        }
        if (property == null) {
            throw new BuildException("output property not defined");
        }
        FileInputStream fis = null;
        BufferedInputStream bis = null;
        Reader instream = null;
        log("loading "+srcFile+" into property "+property,Project.MSG_VERBOSE);
        try {
            final long len = srcFile.length();
            log("file size = "+len,Project.MSG_DEBUG);
            //discard most of really big files
            final int size=(int) len;
            //open up the file
            fis = new FileInputStream(srcFile);
            bis = new BufferedInputStream(fis);
            if (encoding == null) {
                instream = new InputStreamReader(bis);
            }
            else {
                instream = new InputStreamReader(bis, encoding);
            }

            ChainReaderHelper crh = new ChainReaderHelper();
            crh.setBufferSize(size);
            crh.setPrimaryReader(instream);
            crh.setFilterChains(filterChains);
            crh.setProject(project);
            instream = crh.getAssembledReader();

            String text = crh.readFully(instream);

            if (text != null) {
                project.setNewProperty(property, text);
                log("loaded " + text.length() + " characters",Project.MSG_VERBOSE);
                log(property+" := "+text,Project.MSG_DEBUG);
            }

        } catch (final IOException ioe) {
            final String message = "Unable to load file: " + ioe.toString();
            if (failOnError) {
                throw new BuildException(message, ioe, location);
            }
            else {
                log(message, Project.MSG_ERR);
            }
        } catch (final BuildException be) {
            if (failOnError) {
                throw be;
            }
            else {
                log(be.getMessage(), Project.MSG_ERR);
            }
        } finally {
            try {
                if (fis != null) {
                    fis.close();
                }
            } catch (IOException ioex) {
                //ignore
            }
        }
    }

    /**
     * Add the FilterChain element.
     */
    public final void addFilterChain(FilterChain filter) {
        filterChains.addElement(filter);
    }

//end class
}