jisql/src/main/java/org/apache/util/outputformatter/DefaultFormatter.java

/*
 * 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.util.outputformatter;

import joptsimple.OptionParser;
import joptsimple.OptionSet;

import java.io.PrintStream;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;

/**
 * This is the default formatter for Jisql.  It outputs data in a "normal"
 * format that is similar to most other database command line formatters.
 */
public class DefaultFormatter implements JisqlFormatter {
    private boolean trimColumns;
    private int     columnWidth = 2048;        // can be overridden with the -w switch
    private char    spacer      = ' ';
    private boolean printNull   = true;
    private boolean leftJustify;
    private boolean printHeader = true;
    private boolean debug;
    private String  delimiter   = " | ";

    /**
     * Sets a the option list for this formatter.  This formatter accepts the
     * following options:
     *
     * <li><b>-noheader</b> do not print the header column info.</li>
     * <li><b>-spacer</b> The character to use for &quot;empty&quot; space.  This
     * defaults to the space character.  From mrider - &quot;I added the ability to
     * specify the spacer for columns - which used to be the single char ' '. I did
     * this because of brain-dead Windows' command line copy/paste. It seems that when
     * a line of text ends in space, copy does not copy that space. Which makes it
     * difficult to copy/paste into another program. This can probably be ignored
     * most of the time.&quot;</li>
     * <li><b>-delimiter</b> Specify a single character delimiter for columns.</li>
     * <li><b>-trim</b> trim the spaces from columns.</li>
     * <li><b>-nonull</b> print an empty string instead of the word &quot;NULL&quot;
     * when there is a null value.<li>
     * <li><b>-left</b> left justify the output</li>
     * <li><b>-w</b> specify the max width of a column.  The default is 2048</li>
     * <li><b>-debug</b> add debug headers to the output</li>
     * </ul>
     *
     * @param parser the OptionParser to use.
     */
    public void setSupportedOptions(OptionParser parser) {
        parser.accepts("trim");
        parser.accepts("w").withRequiredArg().ofType(Integer.class);
        parser.accepts("spacer").withRequiredArg().ofType(String.class);
        parser.accepts("left");
        parser.accepts("nonull");
        parser.accepts("noheader");
        parser.accepts("debug");
        parser.accepts("delimiter").withRequiredArg().ofType(String.class);
    }

    /**
     * Consumes any options that were specified on the command line.
     *
     * @param options the OptionSet that the main driver is using.
     */
    public void consumeOptions(OptionSet options) {
        if (options.has("trim")) {
            trimColumns = true;
        }

        if (options.has("w")) {
            columnWidth = (Integer) options.valueOf("w");
        }

        if (options.has("spacer")) {
            spacer = ((String) (options.valueOf("spacer"))).charAt(0);
        }

        if (options.has("left")) {
            leftJustify = true;
        }

        if (options.has("nonull")) {
            printNull = false;
        }

        if (options.has("noheader")) {
            printHeader = false;
        }

        if (options.has("debug")) {
            debug = true;
        }

        if (options.hasArgument("delimiter")) {
            delimiter = (String) options.valueOf("delimiter");
        }
    }

    /**
     * Called to output a usage message to the command line window.  This
     * message should contain information on how to call the formatter.
     *
     * @param out the stream to print the output on
     */
    public void usage(PrintStream out) {
        out.println("\t-w specifies the maximum field width for a column.  The default is to output the full width of the column");
        out.println("\t-spacer changes the spacer between columns from a single space to the first character of the argument");
        out.println("\t-noheader do not print any header columns");
        out.println("\t-left left justify the output");
        out.println("\t-trim trim the data output.  This is useful when specifying a delimiter.");
        out.println("\t-nonull print the empty string instead of the word \"NULL\" for null values.");
        out.println("\t-debug shows extra information about the output.");
        out.println("\t-delimiter specifies the delimiter.  The default is \"" + delimiter + "\".");
    }

    /**
     * Outputs a header for a query.  For the DefaultFormatter the data is output
     * by default unless the &quot;noheader&quot; option is specified.
     *
     * @param out - a PrintStream to send any output to.
     * @param metaData - the ResultSetMetaData for the output.
     */
    public void formatHeader(PrintStream out, ResultSetMetaData metaData) throws Exception {
        if (printHeader) {
            int numColumns = metaData.getColumnCount();

            if (debug) {
                for (int i = 1; i <= numColumns; i++) {
                    out.print(formatLabel(metaData.getColumnTypeName(i), metaData.getColumnDisplaySize(i)));
                    out.print(delimiter);
                }
            }
            //
            // output the column names
            //
            for (int i = 1; i <= numColumns; i++) {
                out.print(formatLabel(metaData.getColumnName(i), metaData.getColumnDisplaySize(i)));
                out.print(delimiter);
            }

            out.println();

            //
            // output pretty dividers
            //
            for (int i = 1; i <= numColumns; i++) {
                out.print(formatSeparator(metaData.getColumnName(i), metaData.getColumnDisplaySize(i)));

                if (i == numColumns) {
                    out.print("-|");
                } else {
                    out.print("-+-");
                }
            }

            out.println();
        }
    }

    /**
     * Called to output the data.
     *
     * @param out the PrintStream to output data to.
     * @param resultSet the ResultSet for the row.
     * @param metaData the ResultSetMetaData for the row.
     */
    public void formatData(PrintStream out, ResultSet resultSet, ResultSetMetaData metaData) throws Exception {
        while (resultSet.next()) {
            int numColumns = metaData.getColumnCount();

            for (int i = 1; i <= numColumns; i++) {
                out.print(formatValue(metaData.getColumnName(i), resultSet.getString(i), metaData.getColumnDisplaySize(i)));
                out.print(delimiter);
            }

            out.println();
        }
    }

    /**
     * Outputs a footer for a query.  This is called after all data has been
     * exhausted.  This method isn't used in the DefaultFormatter.
     *
     * @param out the PrintStream to output data to.
     * @param metaData the ResultSetMetaData for the output.
     */
    public void formatFooter(PrintStream out, ResultSetMetaData metaData) {}

    /**
     * Formats a label for output.
     *
     * @param s - the label to format
     * @param width - the width of the field
     * @return the formated label
     */
    private String formatLabel(String s, int width) {
        if (s == null) {
            s = "NULL";
        }

        if (columnWidth != 0) {
            if (width > columnWidth) {
                width = columnWidth;
            }
        }

        if (width < s.length()) {
            width = s.length();
        }

        int len = s.length();

        if (len >= width) {
            return s.substring(0, width);
        }

        int           fillWidth = width - len;
        StringBuilder fill      = new StringBuilder(fillWidth);

        for (int i = 0; i < fillWidth; ++i) {
            fill.append(spacer);
        }

        if (leftJustify) {
            return s + fill;
        } else if (s.startsWith("-")) {
            return "-" + fill + s.substring(1);
        } else {
            return fill + s;
        }
    }

    /**
     * Formats a separator for display.
     *
     * @param s - the field for which the separator is being generated
     * @param width - the width of the field
     * @return the formated separator
     */
    private String formatSeparator(String s, int width) {
        s = "NULL";

        if (columnWidth != 0) {
            if (width > columnWidth) {
                width = columnWidth;
            }
        }

        if (width < s.length()) {
            width = s.length();
        }

        int len = s.length();

        if (len >= width) {
            width = len;
        }

        StringBuilder fill = new StringBuilder(width);

        for (int i = 0; i < width; ++i) {
            fill.append('-');
        }

        if (trimColumns) {
            return fill.toString().trim();
        } else {
            return fill.toString();
        }
    }

    /**
     * Formats a value for display.
     *
     * @param label the label associated with the value (for width purposes)
     * @param s - the value to format
     * @param width - the width of the field from the db.
     * @return the formatted field.
     */
    private String formatValue(String label, String s, int width) {
        if (s == null) {
            if (printNull) {
                s = "NULL";
            } else {
                s = "";
            }
        }

        if (columnWidth != 0) {
            if (width > columnWidth) {
                width = columnWidth;
            }
        }

        if (width < label.length()) {
            width = label.length();
        }

        int len = s.length();

        if (len >= width) {
            if (trimColumns) {
                return s.substring(0, width).trim();
            } else {
                return s.substring(0, width);
            }
        }

        int           fillWidth = width - len;
        StringBuilder fill      = new StringBuilder(fillWidth);

        for (int i = 0; i < fillWidth; ++i) {
            fill.append(spacer);
        }

        StringBuilder returnValue = new StringBuilder();

        if (leftJustify) {
            returnValue.append(s).append(fill);
        } else if (s.startsWith("-")) {
            returnValue.append("-").append(fill).append(s.substring(1));
        } else {
            returnValue.append(fill).append(s);
        }

        if (trimColumns) {
            return returnValue.toString().trim();
        } else {
            return returnValue.toString();
        }
    }
}