concat.java

java ant的源码！非常值得看的源码

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package org.apache.tools.ant.taskdefs;

import java.io.File;
import java.io.Reader;
import java.io.Writer;
import java.io.FileReader;
import java.io.InputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.OutputStream;
import java.io.StringReader;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.Vector;
import java.util.Iterator;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.ProjectComponent;
import org.apache.tools.ant.filters.util.ChainReaderHelper;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.types.FileSet;
import org.apache.tools.ant.types.FileList;
import org.apache.tools.ant.types.FilterChain;
import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.types.ResourceCollection;
import org.apache.tools.ant.types.resources.Restrict;
import org.apache.tools.ant.types.resources.Resources;
import org.apache.tools.ant.types.resources.FileResource;
import org.apache.tools.ant.types.resources.StringResource;
import org.apache.tools.ant.types.resources.selectors.Not;
import org.apache.tools.ant.types.resources.selectors.Exists;
import org.apache.tools.ant.types.resources.selectors.ResourceSelector;
import org.apache.tools.ant.util.FileUtils;
import org.apache.tools.ant.util.ConcatResourceInputStream;

/**
 * This class contains the 'concat' task, used to concatenate a series
 * of files into a single stream. The destination of this stream may
 * be the system console, or a file. The following is a sample
 * invocation:
 *
 * <pre>
 * &lt;concat destfile=&quot;${build.dir}/index.xml&quot;
 *   append=&quot;false&quot;&gt;
 *
 *   &lt;fileset dir=&quot;${xml.root.dir}&quot;
 *     includes=&quot;*.xml&quot; /&gt;
 *
 * &lt;/concat&gt;
 * </pre>
 *
 */
public class Concat extends Task {

    // The size of buffers to be used
    private static final int BUFFER_SIZE = 8192;

    private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();

    private static final ResourceSelector EXISTS = new Exists();
    private static final ResourceSelector NOT_EXISTS = new Not(EXISTS);

    // Attributes.

    /**
     * The destination of the stream. If <code>null</code>, the system
     * console is used.
     */
    private File destinationFile;

    /**
     * Whether or not the stream should be appended if the destination file
     * exists.
     * Defaults to <code>false</code>.
     */
    private boolean append;

    /**
     * Stores the input file encoding.
     */
    private String encoding;

    /** Stores the output file encoding. */
    private String outputEncoding;

    /** Stores the binary attribute */
    private boolean binary;

    // Child elements.

    /**
     * This buffer stores the text within the 'concat' element.
     */
    private StringBuffer textBuffer;

    /**
     * Stores a collection of file sets and/or file lists, used to
     * select multiple files for concatenation.
     */
    private Resources rc;

    /** for filtering the concatenated */
    private Vector filterChains;
    /** ignore dates on input files */
    private boolean forceOverwrite = true;
    /** String to place at the start of the concatented stream */
    private TextElement footer;
    /** String to place at the end of the concatented stream */
    private TextElement header;
    /** add missing line.separator to files **/
    private boolean fixLastLine = false;
    /** endofline for fixlast line */
    private String eolString;
    /** outputwriter */
    private Writer outputWriter = null;

    /**
     * Construct a new Concat task.
     */
    public Concat() {
        reset();
    }

    /**
     * Reset state to default.
     */
    public void reset() {
        append = false;
        forceOverwrite = true;
        destinationFile = null;
        encoding = null;
        outputEncoding = null;
        fixLastLine = false;
        filterChains = null;
        footer = null;
        header = null;
        binary = false;
        outputWriter = null;
        textBuffer = null;
        eolString = System.getProperty("line.separator");
        rc = null;
    }

    // Attribute setters.

    /**
     * Sets the destination file, or uses the console if not specified.
     * @param destinationFile the destination file
     */
    public void setDestfile(File destinationFile) {
        this.destinationFile = destinationFile;
    }

    /**
     * Sets the behavior when the destination file exists. If set to
     * <code>true</code> the stream data will be appended to the
     * existing file, otherwise the existing file will be
     * overwritten. Defaults to <code>false</code>.
     * @param append if true append to the file.
     */
    public void setAppend(boolean append) {
        this.append = append;
    }

    /**
     * Sets the character encoding
     * @param encoding the encoding of the input stream and unless
     *        outputencoding is set, the outputstream.
     */
    public void setEncoding(String encoding) {
        this.encoding = encoding;
        if (outputEncoding == null) {
            outputEncoding = encoding;
        }
    }

    /**
     * Sets the character encoding for outputting
     * @param outputEncoding the encoding for the output file
     * @since Ant 1.6
     */
    public void setOutputEncoding(String outputEncoding) {
        this.outputEncoding = outputEncoding;
    }

    /**
     * Force overwrite existing destination file
     * @param force if true always overwrite, otherwise only overwrite
     *              if the output file is older any of the input files.
     * @since Ant 1.6
     */
    public void setForce(boolean force) {
        this.forceOverwrite = force;
    }

    // Nested element creators.

    /**
     * Path of files to concatenate.
     * @return the path used for concatenating
     * @since Ant 1.6
     */
     public Path createPath() {
        Path path = new Path(getProject());
        add(path);
        return path;
    }

    /**
     * Set of files to concatenate.
     * @param set the set of files
     */
    public void addFileset(FileSet set) {
        add(set);
    }

    /**
     * List of files to concatenate.
     * @param list the list of files
     */
    public void addFilelist(FileList list) {
        add(list);
    }

    /**
     * Add an arbitrary ResourceCollection.
     * @param c the ResourceCollection to add.
     * @since Ant 1.7
     */
    public void add(ResourceCollection c) {
        rc = rc == null ? new Resources() : rc;
        rc.add(c);
    }

    /**
     * Adds a FilterChain.
     * @param filterChain a filterchain to filter the concatenated input
     * @since Ant 1.6
     */
    public void addFilterChain(FilterChain filterChain) {
        if (filterChains == null) {
            filterChains = new Vector();
        }
        filterChains.addElement(filterChain);
    }

    /**
     * This method adds text which appears in the 'concat' element.
     * @param text the text to be concated.
     */
    public void addText(String text) {
        if (textBuffer == null) {
            // Initialize to the size of the first text fragment, with
            // the hopes that it's the only one.
            textBuffer = new StringBuffer(text.length());
        }

        // Append the fragment -- we defer property replacement until
        // later just in case we get a partial property in a fragment.
        textBuffer.append(text);
    }

    /**
     * Add a header to the concatenated output
     * @param headerToAdd the header
     * @since Ant 1.6
     */
    public void addHeader(TextElement headerToAdd) {
        this.header = headerToAdd;
    }

    /**
     * Add a footer to the concatenated output
     * @param footerToAdd the footer
     * @since Ant 1.6
     */
    public void addFooter(TextElement footerToAdd) {
        this.footer = footerToAdd;
    }

    /**
     * Append line.separator to files that do not end
     * with a line.separator, default false.
     * @param fixLastLine if true make sure each input file has
     *                    new line on the concatenated stream
     * @since Ant 1.6
     */
    public void setFixLastLine(boolean fixLastLine) {
        this.fixLastLine = fixLastLine;
    }

    /**
     * Specify the end of line to find and to add if
     * not present at end of each input file. This attribute
     * is used in conjunction with fixlastline.
     * @param crlf the type of new line to add -
     *              cr, mac, lf, unix, crlf, or dos
     * @since Ant 1.6
     */
    public void setEol(FixCRLF.CrLf crlf) {
        String s = crlf.getValue();
        if (s.equals("cr") || s.equals("mac")) {
            eolString = "\r";
        } else if (s.equals("lf") || s.equals("unix")) {
            eolString = "\n";
        } else if (s.equals("crlf") || s.equals("dos")) {
            eolString = "\r\n";
        }
    }

    /**
     * Set the output writer. This is to allow
     * concat to be used as a nested element.
     * @param outputWriter the output writer.
     * @since Ant 1.6
     */
    public void setWriter(Writer outputWriter) {
        this.outputWriter = outputWriter;
    }

    /**
     * Set the binary attribute. If true, concat will concatenate the files
     * byte for byte. This mode does not allow any filtering or other
     * modifications to the input streams. The default value is false.
     * @since Ant 1.6.2
     * @param binary if true, enable binary mode.
     */
    public void setBinary(boolean binary) {
        this.binary = binary;
    }

    /**
     * Validate configuration options.
     */
    private ResourceCollection validate() {

        // treat empty nested text as no text
        sanitizeText();

        // if binary check if incompatible attributes are used
        if (binary) {
            if (destinationFile == null) {
                throw new BuildException(
                    "destfile attribute is required for binary concatenation");
            }
            if (textBuffer != null) {
                throw new BuildException(
                    "Nested text is incompatible with binary concatenation");
            }
            if (encoding != null || outputEncoding != null) {
                throw new BuildException(
                    "Seting input or output encoding is incompatible with binary"
                    + " concatenation");
            }
            if (filterChains != null) {
                throw new BuildException(
                    "Setting filters is incompatible with binary concatenation");
            }
            if (fixLastLine) {
                throw new BuildException(
                    "Setting fixlastline is incompatible with binary concatenation");
            }
            if (header != null || footer != null) {
                throw new BuildException(
                    "Nested header or footer is incompatible with binary concatenation");
            }
        }
        if (destinationFile != null && outputWriter != null) {
            throw new BuildException(
                "Cannot specify both a destination file and an output writer");
        }
        // Sanity check our inputs.
        if (rc == null && textBuffer == null) {
            // Nothing to concatenate!
            throw new BuildException(
                "At least one resource must be provided, or some text.");
        }
        if (rc != null) {
            // If using resources, disallow inline text. This is similar to
            // using GNU 'cat' with file arguments -- stdin is simply
            // ignored.
            if (textBuffer != null) {
                throw new BuildException(
                    "Cannot include inline text when using resources.");
            }
            Restrict noexistRc = new Restrict();
            noexistRc.add(NOT_EXISTS);
            noexistRc.add(rc);
            for (Iterator i = noexistRc.iterator(); i.hasNext();) {
                log(i.next() + " does not exist.", Project.MSG_ERR);
            }
            if (destinationFile != null) {
                for (Iterator i = rc.iterator(); i.hasNext();) {
                    Object o = i.next();
                    if (o instanceof FileResource) {
                        File f = ((FileResource) o).getFile();
                        if (FILE_UTILS.fileNameEquals(f, destinationFile)) {
                            throw new BuildException("Input file \""
                                + f + "\" is the same as the output file.");
                        }
                    }
                }
            }
            Restrict existRc = new Restrict();
            existRc.add(EXISTS);
            existRc.add(rc);
            boolean outofdate = destinationFile == null || forceOverwrite;
            if (!outofdate) {
                for (Iterator i = existRc.iterator(); !outofdate && i.hasNext();) {
                    Resource r = (Resource) i.next();
                    outofdate =
                        (r.getLastModified() == 0L
                         || r.getLastModified() > destinationFile.lastModified());
                }
            }
            if (!outofdate) {
                log(destinationFile + " is up-to-date.", Project.MSG_VERBOSE);
                return null; // no need to do anything
            }
            return existRc;
        } else {
            StringResource s = new StringResource();
            s.setProject(getProject());
            s.setValue(textBuffer.toString());
            return s;
        }