org.pentaho.di.core.database
Class SqlCommentScrubber

java.lang.Object
  org.pentaho.di.core.database.SqlCommentScrubber

public class SqlCommentScrubber
extends Object

This class represents a parser that will remove SQL comments (both multi-line and single-line) from a string representing a SQL query. It respects the notion of a string literal, such that if a comment appears in a string literal, it is treated as part of the string instead of a comment. Both single-quoted and double-quoted string literals are supported, including nested quotes (whether the SQL dialect supports them or not).

Author:

Matt Burgess

Field Summary

static int	EOF End-of-File (EOF) indicator
static int	EOL End-of-Line (EOL) indicator

Method Summary

static String

removeComments(String text) This method will remove SQL comments (both multi-line and single-line) from a string representing a SQL query.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EOF

public static final int EOF

End-of-File (EOF) indicator

See Also:

Constant Field Values

EOL

public static final int EOL

End-of-Line (EOL) indicator

See Also:

Constant Field Values

Method Detail

removeComments

public static String removeComments(String text)

This method will remove SQL comments (both multi-line and single-line) from a string representing a SQL query. It respects the notion of a string literal, such that if a comment appears in a string literal, it is treated as part of the string instead of a comment. A simple state machine is implemented, keeping track of whether the current character is starting, ending, or inside a comment construct. The state machine also checks to see if the current character is starting, ending, or inside a single-quoted string literal, as this takes precedence over comment constructs. In other words, comments inside strings are not actually comments, they are part of the string literal.

Parameters:

text - a string representing the SQL query to parse and from which to remove comments

Returns:

the input string with SQL comments removed, or null if the input string is null