直接上代码,经过验证。
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"); } } }