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author | Peter Mount <peter@retep.org.uk> | 2000-04-17 20:07:56 +0000 |
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committer | Peter Mount <peter@retep.org.uk> | 2000-04-17 20:07:56 +0000 |
commit | 25dadc85140b1f688a4cf0c2de8b961a07b10f11 (patch) | |
tree | 14c91b7e37ca13fba1a4880687cf02bd2dad2de2 /src/interfaces/jdbc/org/postgresql/util/PGtokenizer.java | |
parent | aafff4af162dcf2be91fcd67db6881d6cf166565 (diff) | |
download | postgresql-25dadc85140b1f688a4cf0c2de8b961a07b10f11.tar.gz |
Another attempt at 7.0
Diffstat (limited to 'src/interfaces/jdbc/org/postgresql/util/PGtokenizer.java')
-rw-r--r-- | src/interfaces/jdbc/org/postgresql/util/PGtokenizer.java | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/src/interfaces/jdbc/org/postgresql/util/PGtokenizer.java b/src/interfaces/jdbc/org/postgresql/util/PGtokenizer.java new file mode 100644 index 0000000000..b9d1bb68ff --- /dev/null +++ b/src/interfaces/jdbc/org/postgresql/util/PGtokenizer.java @@ -0,0 +1,197 @@ +package org.postgresql.util; + +import java.sql.*; +import java.util.*; + +/** + * This class is used to tokenize the text output of org.postgres. + * + * <p>It's mainly used by the geometric classes, but is useful in parsing any + * output from custom data types output from org.postgresql. + * + * @see org.postgresql.geometric.PGbox + * @see org.postgresql.geometric.PGcircle + * @see org.postgresql.geometric.PGlseg + * @see org.postgresql.geometric.PGpath + * @see org.postgresql.geometric.PGpoint + * @see org.postgresql.geometric.PGpolygon + */ +public class PGtokenizer +{ + // Our tokens + protected Vector tokens; + + /** + * Create a tokeniser. + * + * <p>We could have used StringTokenizer to do this, however, we needed to + * handle nesting of '(' ')' '[' ']' '<' and '>' as these are used + * by the geometric data types. + * + * @param string containing tokens + * @param delim single character to split the tokens + */ + public PGtokenizer(String string,char delim) + { + tokenize(string,delim); + } + + /** + * This resets this tokenizer with a new string and/or delimiter. + * + * @param string containing tokens + * @param delim single character to split the tokens + */ + public int tokenize(String string,char delim) + { + tokens = new Vector(); + + // nest holds how many levels we are in the current token. + // if this is > 0 then we don't split a token when delim is matched. + // + // The Geometric datatypes use this, because often a type may have others + // (usualls PGpoint) imbedded within a token. + // + // Peter 1998 Jan 6 - Added < and > to the nesting rules + int nest=0,p,s; + + for(p=0,s=0;p<string.length();p++) { + char c = string.charAt(p); + + // increase nesting if an open character is found + if(c == '(' || c == '[' || c == '<') + nest++; + + // decrease nesting if a close character is found + if(c == ')' || c == ']' || c == '>') + nest--; + + if(nest==0 && c==delim) { + tokens.addElement(string.substring(s,p)); + s=p+1; // +1 to skip the delimiter + } + + } + + // Don't forget the last token ;-) + if(s<string.length()) + tokens.addElement(string.substring(s)); + + return tokens.size(); + } + + /** + * @return the number of tokens available + */ + public int getSize() + { + return tokens.size(); + } + + /** + * @param n Token number ( 0 ... getSize()-1 ) + * @return The token value + */ + public String getToken(int n) + { + return (String)tokens.elementAt(n); + } + + /** + * This returns a new tokenizer based on one of our tokens. + * + * The geometric datatypes use this to process nested tokens (usually + * PGpoint). + * + * @param n Token number ( 0 ... getSize()-1 ) + * @param delim The delimiter to use + * @return A new instance of PGtokenizer based on the token + */ + public PGtokenizer tokenizeToken(int n,char delim) + { + return new PGtokenizer(getToken(n),delim); + } + + /** + * This removes the lead/trailing strings from a string + * @param s Source string + * @param l Leading string to remove + * @param t Trailing string to remove + * @return String without the lead/trailing strings + */ + public static String remove(String s,String l,String t) + { + if(s.startsWith(l)) s = s.substring(l.length()); + if(s.endsWith(t)) s = s.substring(0,s.length()-t.length()); + return s; + } + + /** + * This removes the lead/trailing strings from all tokens + * @param l Leading string to remove + * @param t Trailing string to remove + */ + public void remove(String l,String t) + { + for(int i=0;i<tokens.size();i++) { + tokens.setElementAt(remove((String)tokens.elementAt(i),l,t),i); + } + } + + /** + * Removes ( and ) from the beginning and end of a string + * @param s String to remove from + * @return String without the ( or ) + */ + public static String removePara(String s) + { + return remove(s,"(",")"); + } + + /** + * Removes ( and ) from the beginning and end of all tokens + * @return String without the ( or ) + */ + public void removePara() + { + remove("(",")"); + } + + /** + * Removes [ and ] from the beginning and end of a string + * @param s String to remove from + * @return String without the [ or ] + */ + public static String removeBox(String s) + { + return remove(s,"[","]"); + } + + /** + * Removes [ and ] from the beginning and end of all tokens + * @return String without the [ or ] + */ + public void removeBox() + { + remove("[","]"); + } + + /** + * Removes < and > from the beginning and end of a string + * @param s String to remove from + * @return String without the < or > + */ + public static String removeAngle(String s) + { + return remove(s,"<",">"); + } + + /** + * Removes < and > from the beginning and end of all tokens + * @return String without the < or > + */ + public void removeAngle() + { + remove("<",">"); + } +} |