The decision of the Java regular expression shaping floating-point type

Floating-point judgment
public static Boolean isdecimal (String str) {
if (Str==null | | "". Equals (str))
return false;
Java.util.regex.Pattern Pattern = Pattern.compile ("[0-9]* (\ \.?) [0-9]* ");
return Pattern.matcher (str). matches ();
}

Integral type judgment
public static boolean isinteger (String str) {
if (str==null)
return false;
Pattern pattern = Pattern.compile ("[0-9]+");
return Pattern.matcher (str). matches ();
}

Floating-point test cases:
public void Testisdecimal () {

Asserttrue ("123", Test.isdecimal ("1"));
Asserttrue ("12.3", Test.isdecimal ("12.3"));
Asserttrue (". 123", Test.isdecimal (". 123"));
Asserttrue ("123.", Test.isdecimal ("123."));

Assertfalse ("", Test.isdecimal (""));
Assertfalse ("null", Test.isdecimal (null));
Assertfalse ("abc", Test.isdecimal ("abc"));
Assertfalse ("123abc", Test.isdecimal ("123abc"));
Assertfalse ("abc123", Test.isdecimal ("abc123"));
Assertfalse ("123.2.2", Test.isdecimal ("123.2.2"));

}

The decision of the Java regular expression shaping floating-point type