com.github.thorqin.toolkit.utility.StringUtils.java Source code

Introduction

Here is the source code for com.github.thorqin.toolkit.utility.StringUtils.java

Source

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.github.thorqin.toolkit.utility;

import org.joda.time.DateTime;
import org.joda.time.format.DateTimeFormatter;
import org.joda.time.format.ISODateTimeFormat;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.regex.Pattern;

/**
 *
 * @author nuo.qin
 */
public final class StringUtils {
    private static Pattern intPattern = Pattern.compile("^[+-]?\\d+$");
    private static Pattern doublePattern = Pattern.compile("^[+-]?\\d*\\.\\d+$");

    public static boolean isInteger(String text) {
        return intPattern.matcher(text).find();
    }

    public static boolean isDouble(String text) {
        return doublePattern.matcher(text).find();
    }

    public static boolean isNumber(String text) {
        return isInteger(text) || isDouble(text);
    }

    public static Set<String> toStringSet(String value) {
        return toStringSet(value, ",");
    }

    public static Set<String> toStringSet(String value, String delimiter) {
        Set<String> result = new HashSet<>();
        if (value == null)
            return result;
        String[] array = value.split(delimiter);
        for (String v : array)
            if (v != null && !v.isEmpty())
                result.add(v);
        return result;
    }

    public static String join(Iterable<String> array) {
        return join(array, ",");
    }

    public static String join(Iterable<String> array, String delimiter) {
        if (array == null)
            return "";
        StringBuilder result = new StringBuilder();
        Iterator<String> it = array.iterator();
        boolean first = true;
        while (it.hasNext()) {
            if (first)
                first = false;
            else
                result.append(delimiter);
            result.append(it.next());
        }
        return result.toString();
    }

    public static String join(Object[] array) {
        return join(array, ",");
    }

    public static String join(Object[] array, String delimiter) {
        if (array == null)
            return "";
        // Cache the length of the delimiter
        // has the side effect of throwing a NullPointerException if
        // the delimiter is null.
        int delimiterLength = delimiter.length();
        // Nothing in the array return empty string
        // has the side effect of throwing a NullPointerException if
        // the array is null.
        if (array.length == 0) {
            return "";
        }
        // Only one thing in the array, return it.
        if (array.length == 1) {
            if (array[0] == null) {
                return "";
            }
            return array[0].toString();
        }
        // Make a pass through and determine the size
        // of the resulting string.
        int length = 0;
        for (int i = 0; i < array.length; i++) {
            if (array[i] != null) {
                length += array[i].toString().length();
            }
            if (i < array.length - 1) {
                length += delimiterLength;
            }
        }
        // Make a second pass through and concatenate everything
        // into a string buffer.
        StringBuilder result = new StringBuilder(length);
        for (int i = 0; i < array.length; i++) {
            if (array[i] != null) {
                result.append(array[i].toString());
            }
            if (i < array.length - 1) {
                result.append(delimiter);
            }
        }
        return result.toString();
    }

    /**
     * Convert name from 'xxxYyyyZzzz' value to 'xxxx_yyyy_zzzz' value
     * @param name String that separated in camel form
     * @return String that separated by underline
     */
    public static String camelToUnderline(String name) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < name.length(); i++) {
            char ch = name.charAt(i);
            if (ch >= 'A' && ch <= 'Z') {
                if (sb.length() > 0) {
                    sb.append('_');
                    sb.append((char) (ch + 32));
                } else
                    sb.append((char) (ch + 32));
            } else {
                sb.append(ch);
            }
        }
        return sb.toString();
    }

    public static DateTime parseISO8601(String dateTime) {
        DateTimeFormatter formatter = ISODateTimeFormat.dateTimeParser();
        return formatter.parseDateTime(dateTime);
    }

    public static String toISO8601(DateTime dateTime) {
        DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
        return dateTime.toDateTimeISO().toString(formatter);
    }

    /**
     * Convert name from 'xxxx_yyyy_zzzz' value to 'xxxYyyyZzzz' value
     * @param name String that separated by underline
     * @return String that separated in camel form
     */
    public static String underlineToCamel(String name) {
        StringBuilder sb = new StringBuilder();
        boolean upperCaseLetter = false;
        for (int i = 0; i < name.length(); i++) {
            char ch = name.charAt(i);
            if (ch == '_') {
                upperCaseLetter = true;
            } else {
                if (upperCaseLetter && ch >= 'a' && ch <= 'z') {
                    sb.append((char) (ch - 32));
                } else
                    sb.append(ch);
                upperCaseLetter = false;
            }
        }
        return sb.toString();
    }
}