org.projectforge.web.core.JsonBuilder.java Source code

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Here is the source code for org.projectforge.web.core.JsonBuilder.java

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/////////////////////////////////////////////////////////////////////////////
//
// Project ProjectForge Community Edition
//         www.projectforge.org
//
// Copyright (C) 2001-2013 Kai Reinhard (k.reinhard@micromata.de)
//
// ProjectForge is dual-licensed.
//
// This community edition is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as published
// by the Free Software Foundation; version 3 of the License.
//
// This community edition is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
// Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, see http://www.gnu.org/licenses/.
//
/////////////////////////////////////////////////////////////////////////////

package org.projectforge.web.core;

import java.util.Collection;

import org.apache.commons.lang.ObjectUtils;
import org.apache.commons.lang.StringUtils;

public class JsonBuilder {
    final private StringBuffer buf = new StringBuffer();

    /**
     * Creates Json result string from the given list.<br/>
     * [["Horst"], ["Klaus"], ...]] // For single property<br/>
     * [["Klein", "Horst"],["Schmidt", "Klaus"], ...] // For two Properties (e. g. name, first name) [["id:37", "Klein", "Horst"],["id:42",
     * "Schmidt", "Klaus"], ...] // For two Properties (e. g. name, first name) with id. <br/>
     * Uses ObjectUtils.toString(Object) for formatting each value.
     * @param prependId If true, the first column will be returned as "id:<value>".
     * @param col The array representation: List<Object> or List<Object[]>. If null then "[]" is returned.
     * @return
     */
    public static String buildToStringRows(final Collection<?> col, final boolean prependId) {
        if (col == null) {
            return "[]";
        }
        final JsonBuilder builder = new JsonBuilder();
        return builder.append(col, prependId).getAsString();
    }

    public static String buildToStringRows(final Collection<?> col) {
        return buildToStringRows(col, false);
    }

    public String getAsString() {
        return buf.toString();
    }

    /**
     * Appends objects to buffer, e. g.: ["Horst"], ["Klaus"], ... Uses formatValue(Object) to render the values.
     * @param oArray
     * @param prependId If true then id will be prepended at the first column, e. g.: ["id:37", "Klein", "Horst"].
     * @return This (fluent)
     */
    public JsonBuilder append(final Object[] oArray, final boolean prependId) {
        buf.append(" ["); // begin array
        boolean firstCell = true;
        for (Object obj : oArray) {
            if (firstCell == true) {
                firstCell = false;
                buf.append("\"");
                if (prependId == true) {
                    buf.append("id:");
                }
            } else {
                buf.append(",\"");
            }
            // " must be quoted as \":
            buf.append(StringUtils.replace(formatValue(obj), "\"", "\\\"")).append("\"");
        }
        buf.append("]"); // end array
        return this;
    }

    public JsonBuilder append(final Object[] oArray) {
        return append(oArray, false);
    }

    /**
     * Creates Json result string from the given list.<br/>
     * [["Horst"], ["Klaus"], ...]] // For single property<br/>
     * [["Klein", "Horst"],["Schmidt", "Klaus"], ...] // For two Properties (e. g. name, first name) [["id:37", "Klein", "Horst"],["id:42",
     * "Schmidt", "Klaus"], ...] // For two Properties (e. g. name, first name) with id. <br/>
     * Uses formatValue(Object) for formatting each value.
     * @param prependId If true, the first column will be returned as "id:<value>".
     * @param col The array representation: List<Object> or List<Object[]>. If null then "[]" is returned.
     * @return
     */
    public JsonBuilder append(final Collection<?> col, final boolean prependId) {
        if (col == null) {
            buf.append("[]");
            return this;
        }
        // Format: [["1.1", "1.2", ...],["2.1", "2.2", ...]]
        buf.append("[\n");
        boolean firstRow = true;
        for (final Object os : col) {
            if (firstRow == true)
                firstRow = false;
            else
                buf.append(",\n");
            if (os instanceof Object[]) { // Multiple properties
                append((Object[]) os, prependId);
            } else { // Only one property
                append(transform(os));
            }
        }
        buf.append("]"); // end data
        return this;
    }

    public JsonBuilder append(final Collection<?> col) {
        return append(col, false);
    }

    /**
     * @param obj
     * @return
     * @see ObjectUtils#toString(Object)
     */
    protected String formatValue(Object obj) {
        return ObjectUtils.toString(obj);
    }

    protected JsonBuilder append(final Object obj) {
        if (obj instanceof Object[]) {
            return append((Object[]) obj);
        }
        buf.append(" ["); // begin row
        // " must be quoted as \":
        buf.append("\"").append(StringUtils.replace(formatValue(obj), "\"", "\\\"")).append("\"");
        buf.append("]"); // end row
        return this;
    }

    /**
     * Before rendering a obj of e. g. a collection the obj can be transformed e. g. in an Object array of dimension 2 containing label and
     * value.
     * @param obj
     * @return obj (identity function) if not overload.
     */
    protected Object transform(final Object obj) {
        return obj;
    }
}