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/*
* Copyright 2006-2012 The Scriptella Project Team.
*
* Licensed 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 scriptella.driver.csv.opencsv;
import scriptella.util.IOUtils;
import java.io.BufferedReader;
import java.io.Closeable;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
/**
* A very simple CSV reader released under a commercial-friendly license.
*
* @author Glen Smith
* @author Fyodor Kupolov (Performance optimizations)
*
*/
public class CSVReader implements Closeable {
private BufferedReader br;
private boolean hasNext = true;
private char separator;
private char quotechar;
private int skipLines;
private boolean linesSkiped;
/** The default separator to use if none is supplied to the constructor. */
public static final char DEFAULT_SEPARATOR = ',';
/**
* The default quote character to use if none is supplied to the
* constructor.
*/
public static final char DEFAULT_QUOTE_CHARACTER = '"';
/**
* The default line to start reading.
*/
public static final int DEFAULT_SKIP_LINES = 0;
/**
* Constructs CSVReader using a comma for the separator.
*
* @param reader
* the reader to an underlying CSV source.
*/
public CSVReader(Reader reader) {
this(reader, DEFAULT_SEPARATOR);
}
/**
* Constructs CSVReader with supplied separator.
*
* @param reader
* the reader to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries.
*/
public CSVReader(Reader reader, char separator) {
this(reader, separator, DEFAULT_QUOTE_CHARACTER);
}
/**
* Constructs CSVReader with supplied separator and quote char.
*
* @param reader
* the reader to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
*/
public CSVReader(Reader reader, char separator, char quotechar) {
this(reader, separator, quotechar, DEFAULT_SKIP_LINES);
}
/**
* Constructs CSVReader with supplied separator and quote char.
*
* @param reader
* the reader to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
* @param line
* the line number to skip for start reading
*/
public CSVReader(Reader reader, char separator, char quotechar, int line) {
//Kupolov: check if reader already buffered
this.br = IOUtils.asBuffered(reader);
this.separator = separator;
this.quotechar = quotechar;
this.skipLines = line;
}
/**
* Reads the entire file into a List with each element being a String[] of
* tokens.
*
* @return a List of String[], with each String[] representing a line of the
* file.
*
* @throws IOException
* if bad things happen during the read
*/
public List readAll() throws IOException {
List allElements = new ArrayList();
while (hasNext) {
String[] nextLineAsTokens = readNext();
if (nextLineAsTokens != null)
allElements.add(nextLineAsTokens);
}
return allElements;
}
/**
* Reads the next line from the buffer and converts to a string array.
*
* @return a string array with each comma-separated element as a separate
* entry.
*
* @throws java.io.IOException
* if bad things happen during the read
*/
public String[] readNext() throws IOException {
String nextLine = getNextLine();
return hasNext ? parseLine(nextLine) : null;
}
/**
* Reads the next line from the file.
*
* @return the next line from the file without trailing newline
* @throws java.io.IOException
* if bad things happen during the read
*/
private String getNextLine() throws IOException {
if (!this.linesSkiped) {
for (int i = 0; i < skipLines; i++) {
br.readLine();
}
this.linesSkiped = true;
}
String nextLine = br.readLine();
if (nextLine == null) {
hasNext = false;
}
return hasNext ? nextLine : null;
}
/**
* Parses an incoming String and returns an array of elements.
*
* @param nextLine
* the string to parse
* @return the comma-tokenized list of elements, or null if nextLine is null
* @throws java.io.IOException if bad things happen during the read
*/
private String[] parseLine(String nextLine) throws IOException {
if (nextLine == null) {
return null;
}
List tokensOnThisLine = new ArrayList();
StringBuilder sb = new StringBuilder(nextLine.length()); //Kupolov: Use StringBuilder
boolean inQuotes = false;
do {
if (inQuotes) {
// continuing a quoted section, reappend newline
sb.append("\n");
nextLine = getNextLine();
if (nextLine == null)
break;
}
final int length = nextLine.length(); //Kupolov: Use local variable in a loop
for (int i = 0; i < length; i++) {
char c = nextLine.charAt(i);
if (c == quotechar) {
// this gets complex... the quote may end a quoted block, or escape another quote.
// do a 1-char lookahead:
if( inQuotes // we are in quotes, therefore there can be escaped quotes in here.
&& length > (i+1) // there is indeed another character to check.
&& nextLine.charAt(i+1) == quotechar ){ // ..and that char. is a quote also.
// we have two quote chars in a row == one quote char, so consume them both and
// put one on the token. we do *not* exit the quoted text.
sb.append(nextLine.charAt(i+1));
i++;
}else{
inQuotes = !inQuotes;
// the tricky case of an embedded quote in the middle: a,bc"d"ef,g
if(i>2 //not on the begining of the line
&& nextLine.charAt(i-1) != this.separator //not at the begining of an escape sequence
&& length >(i+1) &&
nextLine.charAt(i+1) != this.separator //not at the end of an escape sequence
){
sb.append(c);
}
}
} else if (c == separator && !inQuotes) {
tokensOnThisLine.add(sb.toString());
sb.setLength(0); // start work on next token
} else {
sb.append(c);
}
}
} while (inQuotes);
tokensOnThisLine.add(sb.toString());
return tokensOnThisLine.toArray(new String[tokensOnThisLine.size()]);
}
/**
* Closes the underlying reader.
*
* @throws java.io.IOException if the close fails
*/
public void close() throws IOException{
br.close();
}
}
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