blog.javaclue.jcexchanger.StringElement.java Source code

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Here is the source code for blog.javaclue.jcexchanger.StringElement.java

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/*
 * blog/javaclue/jcexchanger/StringElement.java
 * 
 * Copyright (C) 2010 JackW
 * 
 * This program is free software: you can redistribute it and/or modify it under the terms of the
 * GNU Lesser General Public License as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License along with this library.
 * If not, see <http://www.gnu.org/licenses/>.
 */
package blog.javaclue.jcexchanger;

import org.apache.commons.lang.StringUtils;

public class StringElement extends BaseElement {
    private static final long serialVersionUID = -2448191264843717300L;
    private String value = null;
    private final boolean trim;

    /**
     * construct a StringElement.
     * 
     * @param name
     *            - the name of the element.
     * @param length
     *            - element length
     */
    public StringElement(String name, int length) {
        this(name, length, false, true);
    }

    /**
     * construct a StringElement.
     * 
     * @param name
     *            - the name of the element.
     * @param length
     *            - element length, if isNullable is true, actual element length
     *            will increase by 1.
     * @param isNullable
     *            - if true, an extra character is inserted to the beginning of
     *            the element serving as null indicator.
     */
    public StringElement(String name, int length, boolean isNullable) {
        this(name, length, isNullable, true);
    }

    /**
     * construct a StringElement.
     * 
     * @param name
     *            - the name of the element.
     * @param length
     *            - element length, if isNullable is true, actual element length
     *            will increase by 1.
     * @param isNullable
     *            - if true, an extra character is inserted to the beginning of
     *            the element serving as null indicator.
     * @param trim
     *            - true to trim the string when the value is set. default to
     *            true.
     */
    public StringElement(String name, int length, boolean isNullable, boolean trim) {
        super(name, length, isNullable);
        this.trim = trim;
        if (!isNullable)
            value = "";
    }

    public String getFormattedString() {
        return new String(getFormattedBytes());
    }

    public byte[] getFormattedBytes() {
        if (value == null) {
            if (isNullable) {
                if (AppProperties.useNullIndicator()) {
                    return ("Y" + getBlanks(length - 1)).getBytes();
                } else {
                    return getLowValues(length);
                }
            } else {
                return getBlanks(length).getBytes();
            }
        } else {
            String rtn_str = toString();
            if (isNullable && AppProperties.useNullIndicator()) {
                rtn_str = "N" + rtn_str;
            }
            return StringUtils.rightPad(StringUtils.left(rtn_str, length), length, ' ').getBytes();
        }
    }

    public String toString() {
        if (value == null) {
            return null;
        } else {
            return value.toString();
        }
    }

    public String getValue() {
        return this.value;
    }

    /*
     * @param byte array
     */
    public void setValue(byte[] bytes) {
        if (isLowValue(bytes)) {
            value = null;
        } else {
            String field = new String(bytes);
            if (isNullable && field.length() > 0) {
                if (AppProperties.useNullIndicator()) { // use null indicator
                    if ("Y".equalsIgnoreCase(field.substring(0, 1))) {
                        value = null;
                    } else {
                        value = field.substring(1);
                    }
                } else {
                    value = field;
                }
            } else {
                value = field;
            }
            if (trim == true && value != null) {
                value = value.trim();
            }
        }
        if (value != null && value.length() > length) {
            logger.warn("Input \"" + value + "\" exceeds the element size of " + length
                    + ", return from getFormattedString() will be truncated.");
        }
    }

    public static void main(String[] args) {
        StringElement elem = new StringElement("string", 25);
        byte[] bytes = { 0, 0, 0, 0, 0, 0, 0, 0 };
        elem.setValue(bytes);
        System.out.println("LowValue? " + elem.isLowValue(bytes) + ", value: " + elem);
        elem.setValue("I'm a String Element");
        System.out.println(elem.getName() + ".toString() :<" + elem + ">");
        System.out.println(elem.getName() + ".formatted  :<" + elem.getFormattedString() + ">");
        // test null string
        elem = new StringElement("string", 25, true);
        bytes = "Y              ".getBytes();
        elem.setValue(bytes);
        System.out.println("LowValue? " + elem.isLowValue(bytes) + ", value: " + elem);
        elem.setValue("NI'm a String Element");
        System.out.println(elem.getName() + ".toString() :<" + elem + ">");
        System.out.println(elem.getName() + ".formatted  :<" + elem.getFormattedString() + ">");
    }
}