也许你两个都不知道,也许你除了isEmpty/isNotEmpty/isNotBlank/isBlank外,并不知道还有isAnyEmpty/isNoneEmpty/isAnyBlank/isNoneBlank的存在, come on ,让我们一起来探索org.apache.commons.lang3.StringUtils;这个工具类。 isEmpty系列 StringUtils...
or this: select * from users where lower(first_name) = 'fred'; As you can see, the pattern is to make the field you're searching into uppercase or lowercase, and then make your search string also be uppercase or lowercase to match the SQL function you've used. What is indexOf in...
Run the following to run the tests for the chosen vendor specified in lowercase:mvn test -P<vendor>NOTE: there is also a "special" profile for H2 to test that engine in server mode (instead of the default H2 embedded); for that case the profile h2remote is used in the <vendor> ...
UpperCase/LowerCase/SwapCase/Capitalize/Uncapitalize changes the case of a String 更改字符串的大小写 CountMatches counts the number of occurrences of one String in another 计算一个字符串在另一个字符串中出现的次数 IsAlpha/IsNumeric/IsWhitespace/IsAsciiPrintable ...
public static String inWhichCityLowercase(final Person person) { return Optional.ofNullable(person) .map(Person::getLocation) .map(Location::getCity) .map(String::toLowerCase) .orElse("nowhere"); } 1. 2. 3. 4. 5. 6. 7. 采用Optional的写法,逻辑层次一目了然。似无判空,胜却判空,尽在...
returnstr.isEmpty() ?true:false; } /** * 返回索引上的字符 */ publicstaticchargetStr(String str,intindex){ returnstr.charAt(index); } /** * 字符串转换成小写 */ publicstaticString to_lower(String str){ returnstr.toLowerCase(); ...
1:Scanner的使用(了解) (1)在JDK5以后出现的用于键盘录入数据的类。 (2)构造方法: A:讲解了System.in这个东西。 它其实是标准的输入流,对应于键盘录入 B:构造方法 InputStream is = System.in; Scanner(InputStream is) C
Java-defined character classes (using the syntax and definition of java.util.regex.Pattern), e.g., \p{javaLowerCase}, \p{javaWhitespace} Special character classes inside regular character classes: [\d\s], [\D] Unicode line breaks: \R Block quotes: \Q...\E Lookaround (lookahead and lo...
There is a standard naming convention for packages. Names should be in lowercase. With small projects that only have a few packages the names are typically simple (but meaningful!) names: package pokeranalyzer package mycalculator In software companies and large projects, where the packages might ...
Many characters are letters but are neither uppercase nor lowercase nor titlecase. Added in 1.5. Java documentation for java.lang.Character.isLetter(int). Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms ...