📅  最后修改于: 2020-11-14 10:19:27             🧑  作者: Mango
java.util.regex.PatternSyntaxException类表示引发的未经检查的异常,该异常表示正则表达式模式中的语法错误。
以下是java.util.regex.PatternSyntaxException类的声明-
public class PatternSyntaxException
extends IllegalArgumentException
Sr.No | Method & Description |
---|---|
1 | PatternSyntaxException(String desc, String regex, int index)
Constructs a new instance of this class. |
Sr.No | Method & Description |
---|---|
1 | String getDescription()
Retrieves the description of the error. |
2 | int getIndex()
Retrieves the error index. |
3 | String getMessage()
Returns a multi-line string containing the description of the syntax error and its index, the erroneous regular-expression pattern, and a visual indication of the error index within the pattern. |
4 | String getPattern()
Retrieves the erroneous regular-expression pattern. |
此类从以下类继承方法-
以下示例显示java.util.regex.Pattern.PatternSyntaxException类方法的用法。
package com.tutorialspoint;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
public class PatternSyntaxExceptionDemo {
private static String REGEX = "[";
private static String INPUT = "The dog says meow " + "All dogs say meow.";
private static String REPLACE = "cat";
public static void main(String[] args) {
try{
Pattern pattern = Pattern.compile(REGEX);
// get a matcher object
Matcher matcher = pattern.matcher(INPUT);
INPUT = matcher.replaceAll(REPLACE);
} catch(PatternSyntaxException e){
System.out.println("PatternSyntaxException: ");
System.out.println("Description: "+ e.getDescription());
System.out.println("Index: "+ e.getIndex());
System.out.println("Message: "+ e.getMessage());
System.out.println("Pattern: "+ e.getPattern());
}
}
}
让我们编译并运行上述程序,这将产生以下结果-
PatternSyntaxException:
Description: Unclosed character class
Index: 0
Message: Unclosed character class near index 0
[
^
Pattern: [