Java实现从字符串中找出数字字符串的方法小结

int start = 0;
String numStr = null;
for (int j = 0; j < valuesStr.length() - 1; j++) {
 if (Character.isDigit(valuesStr.charAt(j)) == false
  && Character.isDigit(valuesStr.charAt(j + 1)) == true) {
   start = j + 1;
  numStr = valuesStr.substring(start, valuesStr.length());
 }
}

public static boolean isNumeric(String str){
 for (int i = str.length();--i>=0;){
  if (!Character.isDigit(str.charAt(i))){
  return false;
  }
 }
 return true;
}

public static boolean isNumeric(String str){
  Pattern pattern = Pattern.compile("[0-9]*");
  return pattern.matcher(str).matches();
}

public static boolean isNumeric(String str){
  for(int i=str.length();--i>=0;){
   int chr=str.charAt(i);
   if(chr<48 || chr>57)
     return false;
  }
  return true;
}