import java.util.regex.*;

public class ValidationNumber {

public static boolean isintNumber(String aString) {
// 检查一个字符串是否是整数 允许一个正负符号位

if (aString == null || aString.length() < 1) {
return false;
}

Pattern intnumPattern = Pattern.compile("^[+-]?[\\d]+$");
return intnumPattern.matcher(aString).find();
}

public static boolean isNumber(String aString) {
// 检查一个字符串是否全部是数字

if (aString == null || aString.length() < 1) {
return false;
}

Pattern numberPattern = Pattern.compile("^[\\d]+$"); // "^[+-]?([\\d]+)|([\\d]+\\.[\\d]+)$"
return numberPattern.matcher(aString).find();
}

public static boolean isdoubleNumber(String aString) {
//检查一个字符串是否是浮点小数,浮点小数至少一个数字开头,允许一个正负符号位
//中间只出现一个小数点,小数点之后至少一个数字

if (aString == null || aString.length() < 1) {
return false;
}

Pattern doublenumPattern = Pattern.compile("^[+-]?[\\d]+\\.[\\d]+$");
return doublenumPattern.matcher(aString).find();
}

public static void main(String[] args) {
// 测试
String intnum1 = "-23423";
String intnum2 = "234";
String numstring = "234sdf";
String num1 = "234234";
String doublenum1 = "0.123456";
String doublenum2 = "-0.23";
String doublenum3 = ".123123";

System.out.println("" + isintNumber(intnum1));
System.out.println("" + isNumber(num1));
System.out.println("" + isNumber(numstring));

System.out.println("" + isdoubleNumber(doublenum1)); }