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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.hazelcast.org.apache.calcite.avatica;

import java.sql.SQLException;
import java.util.Map;
import java.util.Properties;

/**
 * ConnectStringParser is a utility class that parses or creates a JDBC connect
 * string according to the
 * 
 * OLE DB Connection String Syntax.
 *
 * 

This code was adapted from Mondrian's mondrian.olap.Util class. * The primary differences between this and its Mondrian progenitor are: * *

    *
  • use of regular {@link Properties} for compatibility with the JDBC API * (replaces Mondrian's use of its own order-preserving and case-insensitive * PropertyList)
  • * *
  • ability to pass to {@link #parse} a pre-existing Properties object into * which properties are to be parsed, possibly overriding prior values
  • * *
  • use of {@link SQLException}s rather than unchecked * {@link RuntimeException}s
  • * *
  • static members for parsing and creating connect strings
  • * *
* *

ConnectStringParser has a private constructor. Callers use the static * members: * *

*
{@link #parse(String)} *
Parses the connect string into a new Properties object. * *
{@link #parse(String, Properties)} *
Parses the connect string into an existing Properties object. * *
{@link #getParamString(Properties)} *
Returns a param string, quoted and escaped as needed, to represent the * supplied name-value pairs. *
*/ public class ConnectStringParser { //~ Instance fields -------------------------------------------------------- private final String s; private final int n; private int i; private final StringBuilder nameBuf = new StringBuilder(); private final StringBuilder valueBuf = new StringBuilder(); //~ Constructors ----------------------------------------------------------- /** * Creates a new connect string parser. * * @param s connect string to parse * * @see #parse(String) * @see #parse(String, Properties) */ private ConnectStringParser(String s) { this.s = s; this.i = 0; this.n = s.length(); } //~ Methods ---------------------------------------------------------------- /** * Parses the connect string into a new Properties object. * * @param s connect string to parse * * @return properties object with parsed params * * @throws SQLException error parsing name-value pairs */ public static Properties parse(String s) throws SQLException { return new ConnectStringParser(s).parseInternal(null); } /** * Parses the connect string into an existing Properties object. * * @param s connect string to parse * @param props optional properties object, may be null * * @return properties object with parsed params; if an input * props was supplied, any duplicate properties will have been * replaced by those from the connect string. * * @throws SQLException error parsing name-value pairs */ public static Properties parse(String s, Properties props) throws SQLException { return new ConnectStringParser(s).parseInternal(props); } /** * Parses the connect string into a Properties object. Note that the string * can only be parsed once. Subsequent calls return empty/unchanged * Properties. The original props argument is not altered. * * @param props optional properties object, may be null * * @return properties object with parsed params; if an input * props was supplied, any duplicate properties will have been * replaced by those from the connect string. * * @throws SQLException error parsing name-value pairs */ Properties parseInternal(final Properties props) throws SQLException { final Properties newProps; if (props == null) { newProps = new Properties(); } else { newProps = (Properties) props.clone(); } while (i < n) { parsePair(newProps); } return newProps; } /** * Reads "name=value;" or "name=value<EOF>". * * @throws SQLException error parsing value */ void parsePair(Properties props) throws SQLException { String name = parseName(); String value; if (i >= n) { value = ""; } else if (s.charAt(i) == ';') { i++; value = ""; } else { value = parseValue(); } props.put(name, value); } /** * Reads "name=". Name can contain equals sign if equals sign is doubled. */ String parseName() { nameBuf.setLength(0); while (true) { char c = s.charAt(i); switch (c) { case '=': i++; if ((i < n) && ((c = s.charAt(i)) == '=')) { // doubled equals sign; take one of them, and carry on i++; nameBuf.append(c); break; } String name = nameBuf.toString(); name = name.trim(); return name; case ' ': if (nameBuf.length() == 0) { // ignore preceding spaces i++; break; } // fall through default: nameBuf.append(c); i++; if (i >= n) { return nameBuf.toString().trim(); } } } } /** * Reads "value;" or "value<EOF>" * * @throws SQLException if find an unterminated quoted value */ String parseValue() throws SQLException { char c; // skip over leading white space while ((c = s.charAt(i)) == ' ') { i++; if (i >= n) { return ""; } } if ((c == '"') || (c == '\'')) { String value = parseQuoted(c); // skip over trailing white space while (i < n && s.charAt(i) == ' ') { i++; } if (i >= n) { return value; } else if (s.charAt(i) == ';') { i++; return value; } else { throw new SQLException( "quoted value ended too soon, at position " + i + " in '" + s + "'"); } } else { String value; int semi = s.indexOf(';', i); if (semi >= 0) { value = s.substring(i, semi); i = semi + 1; } else { value = s.substring(i); i = n; } return value.trim(); } } /** * Reads a string quoted by a given character. Occurrences of the quoting * character must be doubled. For example, parseQuoted('"') * reads "a ""new"" string" and returns a "new" * string. * * @throws SQLException if find an unterminated quoted value */ String parseQuoted(char q) throws SQLException { char c = s.charAt(i++); if (c != q) { throw new AssertionError("c != q: c=" + c + " q=" + q); } valueBuf.setLength(0); while (i < n) { c = s.charAt(i); if (c == q) { i++; if (i < n) { c = s.charAt(i); if (c == q) { valueBuf.append(c); i++; continue; } } return valueBuf.toString(); } else { valueBuf.append(c); i++; } } throw new SQLException( "Connect string '" + s + "' contains unterminated quoted value '" + valueBuf.toString() + "'"); } /** * Returns a param string, quoted and escaped as needed, to represent the * supplied name-value pairs. * * @param props name-value pairs * * @return param string, never null */ public static String getParamString(Properties props) { if (props == null) { return ""; } StringBuilder buf = new StringBuilder(); for (Map.Entry entry : toMap(props).entrySet()) { final String name = entry.getKey(); final String value = entry.getValue(); String quote = ""; if (buf.length() > 0) { buf.append(';'); } // write parameter name if (name.startsWith(" ") || name.endsWith(" ")) { quote = "'"; buf.append(quote); } int len = name.length(); for (int i = 0; i < len; ++i) { char c = name.charAt(i); if (c == '=') { buf.append('='); } buf.append(c); } buf.append(quote); // might be empty quote = ""; buf.append('='); // write parameter value len = value.length(); boolean hasSemi = value.indexOf(';') >= 0; boolean hasSQ = value.indexOf('\'') >= 0; boolean hasDQ = value.indexOf('"') >= 0; if (value.startsWith(" ") || value.endsWith(" ")) { quote = "'"; } else if (hasSemi || hasSQ || hasDQ) { // try to choose the least painful quote if (value.startsWith("\"")) { quote = "'"; } else if (value.startsWith("'")) { quote = "\""; } else { quote = hasSQ ? "\"" : "'"; } } char q; if (quote.length() > 0) { buf.append(quote); q = quote.charAt(0); } else { q = '\0'; } for (int i = 0; i < len; ++i) { char c = value.charAt(i); if (c == q) { buf.append(q); } buf.append(c); } buf.append(quote); // might be empty } return buf.toString(); } /** * Converts a {@link Properties} object to a {@link Map}<String, * String>. * *

This is necessary because {@link Properties} is a dinosaur class. It * ought to extend Map<String,String>, but instead * extends {@link java.util.Hashtable}<Object,Object>. * *

Typical usage, to iterate over a {@link Properties}: * *

* * Properties properties;
* for (Map.Entry<String, String> entry = * Util.toMap(properties).entrySet()) {
* println("key=" + entry.getKey() + ", value=" + entry.getValue());
* } *
*
*/ public static Map toMap( final Properties properties) { //noinspection unchecked return (Map) properties; } } // End ConnectStringParser.java




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