    001    // Copyright 2010 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.json;
    016
    017    import java.io.CharArrayWriter;
    018    import java.io.PrintWriter;
    019
    020    /**
    021     * Base class for {@link JSONArray} and {@link JSONObject} that exists to organize the code
    022     * for printing such objects (either compact or pretty).
    023     *
    024     * @since 5.2.0
    025     */
    026    public abstract class JSONCollection
    027    {
    028        /**
    029         * Converts this JSON collection into a parsable string representation.
    030         * <p/>
    031         * Warning: This method assumes that the data structure is acyclical.
    032         * <p>
    033         * Starting in release 5.2, the result will be pretty printed for readability.
    034         *
    035         * @return a printable, displayable, portable, transmittable representation of the object, beginning with
    036         *         <code>{</code>&nbsp;<small>(left brace)</small> and ending with <code>}</code>&nbsp;<small>(right
    037         *         brace)</small>.
    038         */
    039        @Override
    040        public String toString()
    041        {
    042            CharArrayWriter caw = new CharArrayWriter();
    043            PrintWriter pw = new PrintWriter(caw);
    044
    045            JSONPrintSession session = new PrettyPrintSession(pw);
    046
    047            print(session);
    048
    049            pw.close();
    050
    051            return caw.toString();
    052        }
    053
    054        /**
    055         * Converts the JSONObject to a compact or pretty-print string representation
    056         *
    057         * @param compact
    058         *            if true, return minimal format string.
    059         * @since 5.2.0
    060         */
    061        public String toString(boolean compact)
    062        {
    063            return compact ? toCompactString() : toString();
    064        }
    065
    066        /**
    067         * Prints the JSONObject as a compact string (not extra punctuation). This is, essentially, what
    068         * Tapestry 5.1 did inside {@link #toString()}.
    069         */
    070        public String toCompactString()
    071        {
    072            CharArrayWriter caw = new CharArrayWriter();
    073            PrintWriter pw = new PrintWriter(caw);
    074
    075            print(pw);
    076
    077            pw.close();
    078
    079            return caw.toString();
    080        }
    081
    082        /**
    083         * Prints the JSONObject to the write (compactly or not).
    084         *
    085         * @param writer
    086         *            to write content to
    087         * @param compact
    088         *            if true, then write compactly, if false, write with pretty printing
    089         * @since 5.2.1
    090         */
    091        public void print(PrintWriter writer, boolean compact)
    092        {
    093            JSONPrintSession session = compact ? new CompactSession(writer) : new PrettyPrintSession(writer);
    094
    095            print(session);
    096        }
    097
    098        /**
    099         * Prints the JSONObject to the writer compactly (with no extra whitespace).
    100         */
    101        public void print(PrintWriter writer)
    102        {
    103            print(writer, true);
    104        }
    105
    106        /**
    107         * Prints the JSONObject to the writer using indentation (two spaces per indentation level).
    108         */
    109        public void prettyPrint(PrintWriter writer)
    110        {
    111            print(writer, false);
    112        }
    113
    114        /**
    115         * Print the collection in a parsable format using the session to (optionally) inject extra
    116         * whitespace (for "pretty printing").
    117         */
    118        abstract void print(JSONPrintSession session);
    119    }