Java中Pattern类的thw compile(String)方法用于根据作为参数传递给方法的正则表达式创建模式。每当您需要将文本与正则表达式模式进行多次匹配时，请使用Pattern.compile()方法创建一个Pattern实例。
用法:
public static Pattern compile(String regex)
参数：此方法接受一个单个参数regex，它代表编译为模式的给定正则表达式。
返回值：此方法返回从正则表达式编译的模式作为参数传递给该方法。
异常：此方法引发以下异常：
PatternSyntaxException：如果表达式的语法无效，则抛出此异常。
以下示例程序旨在说明compile(String)方法：
示例1:
// Java program to demonstrate
// Pattern.compile() method
import java.util.regex.*;
public class GFG {
public static void main(String[] args)
{
// create a REGEX String
String REGEX = ".*www.*";
// creare the string
// in which you want to search
String actualString
= "www.geeksforgeeks.org";
// compile the regex to create pattern
// using compile() method
Pattern pattern = Pattern.compile(REGEX);
// get a matcher object from pattern
Matcher matcher = pattern.matcher(actualString);
// check whether Regex string is
// found in actualString or not
boolean matches = matcher.matches();
System.out.println("actualString "
+ "contains REGEX = "
+ matches);
}
}
输出：
actualString contains REGEX = true
示例2:
// Java program to demonstrate
// Pattern.compile method
import java.util.regex.*;
public class GFG {
public static void main(String[] args)
{
// create a REGEX String
String REGEX = "brave";
// creare the string
// in which you want to search
String actualString
= "Cat is cute";
// compile the regex to create pattern
// using compile() method
Pattern pattern = Pattern.compile(REGEX);
// check whether Regex string is
// found in actualString or not
boolean matches = pattern
.matcher(actualString)
.matches();
System.out.println("actualString "
+ "contains REGEX = "
+ matches);
}
}
输出：
actualString contains REGEX = false