Here you can find the source of isJapanese(char ch)
public static boolean isJapanese(char ch)
//package com.java2s; //License from project: Open Source License public class Main { public static boolean isJapanese(char ch) { return isHiragana(ch) || isKatakana(ch); }/* w w w. ja v a 2 s . c o m*/ public static boolean isHiragana(char ch) { return ch >= 0x3040 && ch <= 0x309F; } public static boolean isKatakana(char ch) { return ch >= 0x30A0 && ch <= 0x30FF; } }