concat.java

java ant的源码！非常值得看的源码

    }

    /**
     * Execute the concat task.
     */
    public void execute() {
        ResourceCollection c = validate();
        if (c == null) {
            return;
        }
        // Do nothing if no resources (including nested text)
        if (c.size() < 1 && header == null && footer == null) {
            log("No existing resources and no nested text, doing nothing",
                Project.MSG_INFO);
            return;
        }
        if (binary) {
            binaryCat(c);
        } else {
            cat(c);
        }
    }

    /** perform the binary concatenation */
    private void binaryCat(ResourceCollection c) {
        log("Binary concatenation of " + c.size()
            + " resources to " + destinationFile);
        FileOutputStream out = null;
        InputStream in = null;
        try {
            try {
                out = new FileOutputStream(destinationFile);
            } catch (Exception t) {
                throw new BuildException("Unable to open "
                    + destinationFile + " for writing", t);
            }
            in = new ConcatResourceInputStream(c);
            ((ConcatResourceInputStream) in).setManagingComponent(this);
            Thread t = new Thread(new StreamPumper(in, out));
            t.start();
            try {
                t.join();
            } catch (InterruptedException e) {
                try {
                    t.join();
                } catch (InterruptedException ee) {
                    // Empty
                }
            }
        } finally {
            FileUtils.close(in);
            if (out != null) {
                try {
                    out.close();
                } catch (Exception ex) {
                    throw new BuildException(
                        "Unable to close " + destinationFile, ex);
                }
            }
        }
    }

    /** perform the concatenation */
    private void cat(ResourceCollection c) {
        OutputStream os = null;
        char[] buffer = new char[BUFFER_SIZE];

        try {
            PrintWriter writer = null;

            if (outputWriter != null) {
                writer = new PrintWriter(outputWriter);
            } else {
                if (destinationFile == null) {
                    // Log using WARN so it displays in 'quiet' mode.
                    os = new LogOutputStream(this, Project.MSG_WARN);
                } else {
                    // ensure that the parent dir of dest file exists
                    File parent = destinationFile.getParentFile();
                    if (!parent.exists()) {
                        parent.mkdirs();
                    }
                    os = new FileOutputStream(destinationFile.getAbsolutePath(),
                                              append);
                }
                if (outputEncoding == null) {
                    writer = new PrintWriter(
                        new BufferedWriter(
                            new OutputStreamWriter(os)));
                } else {
                    writer = new PrintWriter(
                        new BufferedWriter(
                            new OutputStreamWriter(os, outputEncoding)));
                }
            }
            if (header != null) {
                if (header.getFiltering()) {
                    concatenate(
                        buffer, writer, new StringReader(header.getValue()));
                } else {
                    writer.print(header.getValue());
                }
            }
            if (c.size() > 0) {
                concatenate(buffer, writer, new MultiReader(c));
            }
            if (footer != null) {
                if (footer.getFiltering()) {
                    concatenate(
                        buffer, writer, new StringReader(footer.getValue()));
                } else {
                    writer.print(footer.getValue());
                }
            }
            writer.flush();
            if (os != null) {
                os.flush();
            }
        } catch (IOException ioex) {
            throw new BuildException("Error while concatenating: "
                                     + ioex.getMessage(), ioex);
        } finally {
            FileUtils.close(os);
        }
    }

    /** Concatenate a single reader to the writer using buffer */
    private void concatenate(char[] buffer, Writer writer, Reader in)
        throws IOException {
        if (filterChains != null) {
            ChainReaderHelper helper = new ChainReaderHelper();
            helper.setBufferSize(BUFFER_SIZE);
            helper.setPrimaryReader(in);
            helper.setFilterChains(filterChains);
            helper.setProject(getProject());
            in = new BufferedReader(helper.getAssembledReader());
        }
        while (true) {
            int nRead = in.read(buffer, 0, buffer.length);
            if (nRead == -1) {
                break;
            }
            writer.write(buffer, 0, nRead);
        }
        writer.flush();
    }

    /**
     * Treat empty nested text as no text.
     *
     * <p>Depending on the XML parser, addText may have been called
     * for &quot;ignorable whitespace&quot; as well.</p>
     */
    private void sanitizeText() {
        if (textBuffer != null) {
            if (textBuffer.substring(0).trim().length() == 0) {
                textBuffer = null;
            }
        }
    }

    /**
     * sub element points to a file or contains text
     */
    public static class TextElement extends ProjectComponent {
        private String   value = "";
        private boolean  trimLeading = false;
        private boolean  trim = false;
        private boolean  filtering = true;
        private String   encoding = null;

        /**
         * whether to filter the text in this element
         * or not.
         *
         * @param filtering true if the text should be filtered.
         *                  the default value is true.
         */
        public void setFiltering(boolean filtering) {
            this.filtering = filtering;
        }

        /** return the filtering attribute */
        private boolean getFiltering() {
            return filtering;
        }

        /**
         * The encoding of the text element
         *
         * @param encoding the name of the charset used to encode
         */
        public void setEncoding(String encoding) {
            this.encoding = encoding;
        }

        /**
         * set the text using a file
         * @param file the file to use
         * @throws BuildException if the file does not exist, or cannot be
         *                        read
         */
        public void setFile(File file) throws BuildException {
            // non-existing files are not allowed
            if (!file.exists()) {
                throw new BuildException("File " + file + " does not exist.");
            }

            BufferedReader reader = null;
            try {
                if (this.encoding == null) {
                    reader = new BufferedReader(new FileReader(file));
                } else {
                    reader = new BufferedReader(
                        new InputStreamReader(new FileInputStream(file),
                                              this.encoding));
                }
                value = FileUtils.readFully(reader);
            } catch (IOException ex) {
                throw new BuildException(ex);
            } finally {
                FileUtils.close(reader);
            }
        }

        /**
         * set the text using inline
         * @param value the text to place inline
         */
        public void addText(String value) {
            this.value += getProject().replaceProperties(value);
        }

        /**
         * s:^\s*:: on each line of input
         * @param strip if true do the trim
         */
        public void setTrimLeading(boolean strip) {
            this.trimLeading = strip;
        }

        /**
         * whether to call text.trim()
         * @param trim if true trim the text
         */
        public void setTrim(boolean trim) {
            this.trim = trim;
        }

        /**
         * @return the text, after possible trimming
         */
        public String getValue() {
            if (value == null) {
                value = "";
            }
            if (value.trim().length() == 0) {
                value = "";
            }
            if (trimLeading) {
                char[] current = value.toCharArray();
                StringBuffer b = new StringBuffer(current.length);
                boolean startOfLine = true;
                int pos = 0;
                while (pos < current.length) {
                    char ch = current[pos++];
                    if (startOfLine) {
                        if (ch == ' ' || ch == '\t') {
                            continue;
                        }
                        startOfLine = false;
                    }
                    b.append(ch);
                    if (ch == '\n' || ch == '\r') {
                        startOfLine = true;
                    }
                }
                value = b.toString();
            }
            if (trim) {
                value = value.trim();
            }
            return value;
        }
    }

    /**
     * This class reads from each of the source files in turn.
     * The concatentated result can then be filtered as
     * a single stream.
     */
    private class MultiReader extends Reader {
        private Reader reader = null;
        private int    lastPos = 0;
        private char[] lastChars = new char[eolString.length()];
        private boolean needAddSeparator = false;
        private Iterator i;

        private MultiReader(ResourceCollection c) {
            i = c.iterator();
        }

        private Reader getReader() throws IOException {
            if (reader == null && i.hasNext()) {
                Resource r = (Resource) i.next();
                log("Concating " + r.toLongString(), Project.MSG_VERBOSE);
                InputStream is = r.getInputStream();
                reader = new BufferedReader(encoding == null
                    ? new InputStreamReader(is)
                    : new InputStreamReader(is, encoding));
                Arrays.fill(lastChars, (char) 0);
            }
            return reader;
        }

        private void nextReader() throws IOException {
            close();
            reader = null;
        }

        /**
         * Read a character from the current reader object. Advance
         * to the next if the reader is finished.
         * @return the character read, -1 for EOF on the last reader.
         * @exception IOException - possibly thrown by the read for a reader
         *            object.
         */
        public int read() throws IOException {
            if (needAddSeparator) {
                int ret = eolString.charAt(lastPos++);
                if (lastPos >= eolString.length()) {
                    lastPos = 0;
                    needAddSeparator = false;
                }
                return ret;
            }
            while (getReader() != null) {
                int ch = getReader().read();
                if (ch == -1) {
                    nextReader();
                    if (fixLastLine && isMissingEndOfLine()) {
                        needAddSeparator = true;
                        lastPos = 0;
                    }
                } else {
                    addLastChar((char) ch);
                    return ch;
                }
            }
            return -1;
        }

        /**
         * Read into the buffer <code>cbuf</code>.
         * @param cbuf The array to be read into.
         * @param off The offset.
         * @param len The length to read.
         * @exception IOException - possibly thrown by the reads to the
         *            reader objects.
         */
        public int read(char[] cbuf, int off, int len)
            throws IOException {

            int amountRead = 0;
            while (getReader() != null || needAddSeparator) {
                if (needAddSeparator) {
                    cbuf[off] = eolString.charAt(lastPos++);
                    if (lastPos >= eolString.length()) {
                        lastPos = 0;
                        needAddSeparator = false;
                    }
                    len--;
                    off++;
                    amountRead++;
                    if (len == 0) {
                        return amountRead;
                    }
                    continue;
                }
                int nRead = getReader().read(cbuf, off, len);
                if (nRead == -1 || nRead == 0) {
                    nextReader();
                    if (fixLastLine && isMissingEndOfLine()) {
                        needAddSeparator = true;
                        lastPos = 0;
                    }
                } else {
                    if (fixLastLine) {
                        for (int i = nRead;
                                 i > (nRead - lastChars.length);
                                 --i) {
                            if (i <= 0) {
                                break;
                            }
                            addLastChar(cbuf[off + i - 1]);
                        }
                    }
                    len -= nRead;
                    off += nRead;
                    amountRead += nRead;
                    if (len == 0) {
                        return amountRead;
                    }
                }
            }
            if (amountRead == 0) {
                return -1;
            } else {
                return amountRead;
            }
        }

        /**
         * Close the current reader
         */
        public void close() throws IOException {
            if (reader != null) {
                reader.close();
            }
        }

        /**
         * if checking for end of line at end of file
         * add a character to the lastchars buffer
         */
        private void addLastChar(char ch) {
            for (int i = lastChars.length - 2; i >= 0; --i) {
                lastChars[i] = lastChars[i + 1];
            }
            lastChars[lastChars.length - 1] = ch;
        }

        /**
         * return true if the lastchars buffer does
         * not contain the lineseparator
         */
        private boolean isMissingEndOfLine() {
            for (int i = 0; i < lastChars.length; ++i) {
                if (lastChars[i] != eolString.charAt(i)) {
                    return true;
                }
            }
            return false;
        }
    }

}