Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * 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.
 */

public class Main {
    /**
     * <p>
     * Gets <code>n</code> characters from the middle of a String.
     * </p>
     * <p/>
     * <p>
     * If <code>n</code> characters are not available, the remainder of the String will be returned without an
     * exception. If the String is <code>null</code>, <code>null</code> will be returned.
     * </p>
     *
     * @param str the String to get the characters from
     * @param pos the position to start from
     * @param len the length of the required String
     * @return the leftmost characters
     * @throws IndexOutOfBoundsException if pos is out of bounds
     * @throws IllegalArgumentException if len is less than zero
     */
    public static String mid(String str, int pos, int len) {
        if ((pos < 0) || ((str != null) && (pos > str.length()))) {
            throw new StringIndexOutOfBoundsException("String index " + pos + " is out of bounds");
        }
        if (len < 0) {
            throw new IllegalArgumentException("Requested String length " + len + " is less than zero");
        }
        if (str == null) {
            return null;
        }
        if (str.length() <= (pos + len)) {
            return str.substring(pos);
        } else {
            return str.substring(pos, pos + len);
        }
    }

    /**
     * <p>
     * Gets a substring from the specified string avoiding exceptions.
     * </p>
     * <p/>
     * <p>
     * A negative start position can be used to start <code>n</code> characters from the end of the String.
     * </p>
     *
     * @param str the String to get the substring from
     * @param start the position to start from, negative means count back from the end of the String by this many
     * characters
     * @return substring from start position
     */
    public static String substring(String str, int start) {
        if (str == null) {
            return null;
        }

        // handle negatives, which means last n characters
        if (start < 0) {
            start = str.length() + start; // remember start is negative
        }

        if (start < 0) {
            start = 0;
        }
        if (start > str.length()) {
            return "";
        }

        return str.substring(start);
    }

    /**
     * <p>
     * Gets a substring from the specified String avoiding exceptions.
     * </p>
     * <p/>
     * <p>
     * A negative start position can be used to start/end <code>n</code> characters from the end of the String.
     * </p>
     *
     * @param str the String to get the substring from
     * @param start the position to start from, negative means count back from the end of the string by this many
     * characters
     * @param end the position to end at (exclusive), negative means count back from the end of the String by this many
     * characters
     * @return substring from start position to end positon
     */
    public static String substring(String str, int start, int end) {
        if (str == null) {
            return null;
        }

        // handle negatives
        if (end < 0) {
            end = str.length() + end; // remember end is negative
        }
        if (start < 0) {
            start = str.length() + start; // remember start is negative
        }

        // check length next
        if (end > str.length()) {
            // check this works.
            end = str.length();
        }

        // if start is greater than end, return ""
        if (start > end) {
            return "";
        }

        if (start < 0) {
            start = 0;
        }
        if (end < 0) {
            end = 0;
        }

        return str.substring(start, end);
    }
}