Learn Java Programming

Java Basics

java.util.regex.PatternSyntaxException: Dangling meta character ‘*’ near index 0

The java exception java.util.regex.PatternSyntaxException: Dangling meta character ‘*’ near index 0 happens when the string is matched by the regular expression meta character such as “*”, “+”, “?”. In a search string, the regular expression meta characters (“*”, “+”, “?”) must escape. The regular expression contains meta characters such as

java.util.regex.PatternSyntaxException: Unclosed character class near index 0

The java exception java.util.regex.PatternSyntaxException: Unclosed character class near index 0 happens when the string is matched by the regular expression special character ‘[’ open square bracket. In a search string, the special character (open square bracket) must escape. The regular expression uses the “[ ]” square bracket to match one

java.util.regex.PatternSyntaxException: Unclosed group near index 1

The regular expression uses the “( )” round bracket to identify the matching groups in a string. The matched character in the round bracket identified as a match group in a string. The exception “java.util.regex.PatternSyntaxException: Unclosed group near index” will be thrown if the open round bracket is available without

java.util.regex.PatternSyntaxException: Unmatched closing ‘)’

The java exception java.util.regex.PatternSyntaxException: Unmatched closing ‘)’ happens when the string is matched by the regular expression special character ‘)’ closing parentheses. In a search string, the character “(” and “)” and “{” and “}” are special characters in regular expression. these dialect characters have to be escaped. You need to escape ‘(‘ and ‘)’ with ‘\\(‘ and ‘\\)’ The

java.util.regex.PatternSyntaxException: Unexpected internal error near index 1

The backward slash “\” is used to escape characters in the java string. If a string contains a backward slash “\”, a escape character is added along with backward slash “\”. For example, a String “Yawin\tutor” is created as “Yawin\\tutor” in java. In regular expression if you use single backward

java.util.regex.PatternSyntaxException: Illegal repetition

The java exception java.util.regex.PatternSyntaxException: Illegal repetition occurs when the regex dialects ‘{’ and ‘}’ are not used for repetition qualifier. In the regex dialect, the ‘{‘ and ‘}’ are special in java. They are the opening and closing tokens for the {m, n} repetition quantifier where m and n are

java.util.regex.PatternSyntaxException: Unclosed counted closure near index

The java exception java.util.regex.PatternSyntaxException: Unclosed counted closure near index occurs when a string matches by the regular expression special character ‘{’ open curly bracket without close curly bracket. In a search string, the special character (close curly bracket) must be added. The regular expression uses the “{ }” curly bracket

java.util.regex.PatternSyntaxException: Illegal repetition near index

The java exception java.util.regex.PatternSyntaxException: Illegal repetition near index 0 occurs when the regular expression special characters such as $ { } are used inside the search string. When processing in the regular expression, the special characters have significant meaning. It is necessary to add a special character with an escape

java.util.regex.PatternSyntaxException: Illegal character range near index

The java exception java.util.regex.PatternSyntaxException: Illegal character range near index occurs when an Illegal or inappropriate character range is used to match the regular expression. The range is defined by a hyphen in between minimum and maximum values. If an invalid minimum or maximum value is specified in the regular expression,

How to fix NullPointerException in Java

The java.lang.NullPointerException occurs when a java variable does not point to any object and is accessed for any operation. The java.lang.NullPointerException is a runtime exception. The java.lang.NullPointerException is an exception to runtime. The java NullPointerException occurs when a variable is declared but is not assigned to an object until you