子表达式/元字符“\d”匹配数字。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "\d 24";       String input = "This is sample text 12 24 56 89 24";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：2示例 2以下是一个 Java 程序... 阅读更多

子表达式/元字符“\S”匹配非空白字符。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "\S";       String input = "Hello how are you welcome to Tutorialspoint !";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：38示例 2import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; ... 阅读更多

子表达式/元字符“\s”匹配空白字符等价物。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "\s";       String input = "Hello how are you welcome to Tutorialspoint !";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：7示例 2以下示例读取一个字符串... 阅读更多

子表达式/元字符“\W”匹配非单词字符。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main(String args[]) {       String regex = "\W!";       String input = "Hello how are you welcome to Tutorialspoint !";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：1示例 2以下示例读取 5 个字符串值，并打印包含... 阅读更多

子表达式/元字符“\w”匹配单词字符，即 a 到 z 和 A 到 Z 以及 0 到 9。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "\w to";       String input = "Hello how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);   ... 阅读更多

子表达式/元字符“[^...]”匹配任何不在括号中的单个字符。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class SpecifiedCharacters {    public static void main( String args[] ) {       String regex = "[^hwtyoupi]";       String input = "Hi how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：21示例 2以下 Java 程序接受... 阅读更多

子表达式/元字符“re*”匹配前面表达式的 0 次或多次出现。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "aabc*";       String input = "aabcabcaabcabbcaabcbcaabc";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：4示例 2import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class MatchAllCharacters ... 阅读更多

@ConstructorProperties 注解来自 java.beans 包，用于通过带注解的构造函数将 JSON 反序列化为 Java 对象。此注解自 Jackson 2.7 版本起支持。此注解的工作方式非常简单，无需为构造函数中的每个参数添加注解，我们可以为每个构造函数参数提供一个包含属性名称的数组。语法@Documented @Target(value=CONSTRUCTOR) @Retention(value=RUNTIME) public @interface ConstructorProperties示例import com.fasterxml.jackson.databind.ObjectMapper; import java.beans.ConstructorProperties; public class ConstructorPropertiesAnnotationTest {    public static void main(String args[]) throws Exception {       ObjectMapper mapper = new ObjectMapper();       Employee emp = new Employee(115, "Raja");       String jsonString = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(emp);   ... 阅读更多

子表达式/元字符“\A”匹配整个字符串的开头。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "\AHi";       String input = "Hi how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：1示例 2以下 Java 程序接受一个字符串... 阅读更多

子表达式/元字符“.”匹配任何单个字符，但换行符除外。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class MatchesAll {    public static void main( String args[] ) {       String regex = ".";       String input = "Hi how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：40示例 2以下 Java 程序接受 5 个... 阅读更多