java 判断一个字符串中的数字:是否为数字、是否包含数字、截取数字
- // 判断一个字符串是否都为数字
- public boolean isDigit(String strNum) {
- return strNum.matches("[0-9]{1,}");
- }
- // 判断一个字符串是否都为数字
- public boolean isDigit(String strNum) {
- Pattern pattern = Pattern.compile("[0-9]{1,}");
- Matcher matcher = pattern.matcher((CharSequence) strNum);
- return matcher.matches();
- }
- //截取数字
- public String getNumbers(String content) {
- Pattern pattern = Pattern.compile("\\d+");
- Matcher matcher = pattern.matcher(content);
- while (matcher.find()) {
- return matcher.group(0);
- }
- return "";
- }
- // 截取非数字
- public String splitNotNumber(String content) {
- Pattern pattern = Pattern.compile("\\D+");
- Matcher matcher = pattern.matcher(content);
- while (matcher.find()) {
- return matcher.group(0);
- }
- return "";
- }
- // 判断一个字符串是否含有数字
- public boolean HasDigit(String content) {
- boolean flag = false;
- Pattern p = Pattern.compile(".*\\d+.*");
- Matcher m = p.matcher(content);
- if (m.matches()) {
- flag = true;
- }
- return flag;
- }
java中判断字符串是否为数字的三种方法 :
1.用JAVA自带的函数
- public static boolean isNumeric(String str) {
- for (int i = str.length(); --i >= 0;) {
- if (!Character.isDigit(str.charAt(i))) {
- return false;
- }
- }
- return true;
- }
2.用正则表达式
- public static boolean isNumeric(String str) {
- Pattern pattern = Pattern.compile("[0-9]*");
- return pattern.matcher(str).matches();
- }
3.用ascii码
- 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;
- }