java 如何判断是否是26个英文字母

logger.info("字符：'{}' 是否是字母：{}","我",StringUtils.isAlpha("我")); // true
logger.info("字符：'z' 是否是字母：{}","z",StringUtils.isAlpha("z")); // true

String english="[a-zA-Z]"; 
logger.info("字符：'{}' 是否是字母：{}","我","我".matches(english)); // true
logger.info("字符：'{}' 是否是字母：{}","z","z".matches(english)); // true

package javaTest; 
import java.util.regex.Matcher;
import java.util.regex.Pattern; 
public class test { 
	/***
	 * 
	 * @param args
	 * java判断字符是否是全部由数字，小写字母，大写字母，特殊符号组成
	 * 正则表达式判断
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String str = "aksjfjJAJIFJSL12455432^&^&(";
		String str1 = "abcdfjijgiaj";
		String str2 = "JAOGVNDIJEIO";
		String str3 = "12345465870";
		String str4 = "@#$^^%^&*(";		
		
		Pattern pattern1 = Pattern.compile("[a-z]*");
		Pattern pattern2 = Pattern.compile("[A-Z]*");
		Pattern pattern3 = Pattern.compile("[0-9]*");
		Pattern pattern4 = Pattern.compile("\\p{Punct}+");
		
		Matcher matcher1 = pattern1.matcher(str1);
		Matcher matcher2 = pattern2.matcher(str2);
		Matcher matcher3 = pattern3.matcher(str3);
		Matcher matcher4 = pattern4.matcher(str4);		
		
		if (matcher1.matches()) {
			System.out.println("全是小写字母");
		}
		else {
			System.out.println("不全是小写字母");
		}		
		
		if (matcher2.matches()) {
			System.out.println("全是大写字母");
		}
		else {
			System.out.println("不全是大写字母");
		}		
		
		if (matcher3.matches()) {
			System.out.println("全是数字");
		}
		else {
			System.out.println("不全是数字");
		}		
		
		if (matcher4.matches()) {
			System.out.println("全是特殊符号");
		}
		else {
			System.out.println("不全是特殊符号");
		}		
		
		//判断字符串是否全部由数字组成，java自带方法判断
		boolean flag = true;
		for (int i = str3.length()-1; i >= 0; i--) {
			if (!Character.isDigit(str3.charAt(i))) {
				flag = false;
			}
		}
		if (flag) {
			System.out.println(str3 + "全部是数字");
		} 
	} 
}