package com.bizosys.hsearch.loader.csv;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import com.bizosys.hsearch.loader.RowReader;
public class CsvReader implements RowReader {
private BufferedReader br;
private boolean hasNext = true;
private CsvParser parser;
private int skipLines;
private boolean linesSkiped;
/**
* 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, CsvParser.DEFAULT_SEPARATOR, CsvParser.DEFAULT_QUOTE_CHARACTER, CsvParser.DEFAULT_ESCAPE_CHARACTER);
}
/**
* 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, CsvParser.DEFAULT_QUOTE_CHARACTER, CsvParser.DEFAULT_ESCAPE_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, CsvParser.DEFAULT_ESCAPE_CHARACTER, DEFAULT_SKIP_LINES, CsvParser.DEFAULT_STRICT_QUOTES);
}
/**
* Constructs CSVReader with supplied separator, quote char and quote handling
* behavior.
*
* @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 strictQuotes
* sets if characters outside the quotes are ignored
*/
public CsvReader(Reader reader, char separator, char quotechar, boolean strictQuotes) {
this(reader, separator, quotechar, CsvParser.DEFAULT_ESCAPE_CHARACTER, DEFAULT_SKIP_LINES, strictQuotes);
}
/**
* 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 escape
* the character to use for escaping a separator or quote
*/
public CsvReader(Reader reader, char separator,
char quotechar, char escape) {
this(reader, separator, quotechar, escape, DEFAULT_SKIP_LINES, CsvParser.DEFAULT_STRICT_QUOTES);
}
/**
* 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) {
this(reader, separator, quotechar, CsvParser.DEFAULT_ESCAPE_CHARACTER, line, CsvParser.DEFAULT_STRICT_QUOTES);
}
/**
* 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 escape
* the character to use for escaping a separator or quote
* @param line
* the line number to skip for start reading
*/
public CsvReader(Reader reader, char separator, char quotechar, char escape, int line) {
this(reader, separator, quotechar, escape, line, CsvParser.DEFAULT_STRICT_QUOTES);
}
/**
* 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 escape
* the character to use for escaping a separator or quote
* @param line
* the line number to skip for start reading
* @param strictQuotes
* sets if characters outside the quotes are ignored
*/
public CsvReader(Reader reader, char separator, char quotechar, char escape, int line, boolean strictQuotes) {
this(reader, separator, quotechar, escape, line, strictQuotes, CsvParser.DEFAULT_IGNORE_LEADING_WHITESPACE);
}
/**
* 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 escape
* the character to use for escaping a separator or quote
* @param line
* the line number to skip for start reading
* @param strictQuotes
* sets if characters outside the quotes are ignored
* @param ignoreLeadingWhiteSpace
* it true, parser should ignore white space before a quote in a field
*/
public CsvReader(Reader reader, char separator, char quotechar, char escape, int line, boolean strictQuotes, boolean ignoreLeadingWhiteSpace) {
this.br = new BufferedReader(reader);
this.parser = new CsvParser(separator, quotechar, escape, strictQuotes, ignoreLeadingWhiteSpace);
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<String[]> readAll() throws IOException {
List<String[]> allElements = new ArrayList<String[]>();
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 IOException
* if bad things happen during the read
*/
public String[] readNext() throws IOException {
String[] result = null;
do {
String nextLine = getNextLine();
if (!hasNext) {
return result; // should throw if still pending?
}
String[] r = parser.parseLineMulti(nextLine);
if (r.length > 0) {
if (result == null) {
result = r;
} else {
String[] t = new String[result.length+r.length];
System.arraycopy(result, 0, t, 0, result.length);
System.arraycopy(r, 0, t, result.length, r.length);
result = t;
}
}
} while (parser.isPending());
return result;
}
/**
* Reads the next line from the file.
*
* @return the next line from the file without trailing newline
* @throws 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;
}
/**
* Closes the underlying reader.
*
* @throws IOException if the close fails
*/
public void close() throws IOException{
br.close();
}
}