A very simple CSV writer released under a commercial-friendly license.
/**
Copyright 2005 Bytecode Pty Ltd.
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.
*/
import java.io.Closeable;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import java.math.BigDecimal;
import java.sql.Clob;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Time;
import java.sql.Timestamp;
import java.sql.Types;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
/**
* A very simple CSV writer released under a commercial-friendly license.
*
* @author Glen Smith
*
*/
public class CSVWriter implements Closeable {
public static final int INITIAL_STRING_SIZE = 128;
private Writer rawWriter;
private PrintWriter pw;
private char separator;
private char quotechar;
private char escapechar;
private String lineEnd;
/** The character used for escaping quotes. */
public static final char DEFAULT_ESCAPE_CHARACTER = '"';
/** 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 quote constant to use when you wish to suppress all quoting. */
public static final char NO_QUOTE_CHARACTER = '\u0000';
/** The escape constant to use when you wish to suppress all escaping. */
public static final char NO_ESCAPE_CHARACTER = '\u0000';
/** Default line terminator uses platform encoding. */
public static final String DEFAULT_LINE_END = "\n";
private ResultSetHelper resultService = new ResultSetHelperService();
/**
* Constructs CSVWriter using a comma for the separator.
*
* @param writer
* the writer to an underlying CSV source.
*/
public CSVWriter(Writer writer) {
this(writer, DEFAULT_SEPARATOR);
}
/**
* Constructs CSVWriter with supplied separator.
*
* @param writer
* the writer to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries.
*/
public CSVWriter(Writer writer, char separator) {
this(writer, separator, DEFAULT_QUOTE_CHARACTER);
}
/**
* Constructs CSVWriter with supplied separator and quote char.
*
* @param writer
* the writer to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
*/
public CSVWriter(Writer writer, char separator, char quotechar) {
this(writer, separator, quotechar, DEFAULT_ESCAPE_CHARACTER);
}
/**
* Constructs CSVWriter with supplied separator and quote char.
*
* @param writer
* the writer to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
* @param escapechar
* the character to use for escaping quotechars or escapechars
*/
public CSVWriter(Writer writer, char separator, char quotechar, char escapechar) {
this(writer, separator, quotechar, escapechar, DEFAULT_LINE_END);
}
/**
* Constructs CSVWriter with supplied separator and quote char.
*
* @param writer
* the writer to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
* @param lineEnd
* the line feed terminator to use
*/
public CSVWriter(Writer writer, char separator, char quotechar, String lineEnd) {
this(writer, separator, quotechar, DEFAULT_ESCAPE_CHARACTER, lineEnd);
}
/**
* Constructs CSVWriter with supplied separator, quote char, escape char and line ending.
*
* @param writer
* the writer to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
* @param escapechar
* the character to use for escaping quotechars or escapechars
* @param lineEnd
* the line feed terminator to use
*/
public CSVWriter(Writer writer, char separator, char quotechar, char escapechar, String lineEnd) {
this.rawWriter = writer;
this.pw = new PrintWriter(writer);
this.separator = separator;
this.quotechar = quotechar;
this.escapechar = escapechar;
this.lineEnd = lineEnd;
}
/**
* Writes the entire list to a CSV file. The list is assumed to be a
* String[]
*
* @param allLines
* a List of String[], with each String[] representing a line of
* the file.
*/
public void writeAll(List<String[]> allLines) {
for (String[] line : allLines) {
writeNext(line);
}
}
protected void writeColumnNames(ResultSet rs)
throws SQLException {
writeNext(resultService.getColumnNames(rs));
}
/**
* Writes the entire ResultSet to a CSV file.
*
* The caller is responsible for closing the ResultSet.
*
* @param rs the recordset to write
* @param includeColumnNames true if you want column names in the output, false otherwise
*
* @throws java.io.IOException thrown by getColumnValue
* @throws java.sql.SQLException thrown by getColumnValue
*/
public void writeAll(java.sql.ResultSet rs, boolean includeColumnNames) throws SQLException, IOException {
if (includeColumnNames) {
writeColumnNames(rs);
}
while (rs.next())
{
writeNext(resultService.getColumnValues(rs));
}
}
/**
* Writes the next line to the file.
*
* @param nextLine
* a string array with each comma-separated element as a separate
* entry.
*/
public void writeNext(String[] nextLine) {
if (nextLine == null)
return;
StringBuilder sb = new StringBuilder(INITIAL_STRING_SIZE);
for (int i = 0; i < nextLine.length; i++) {
if (i != 0) {
sb.append(separator);
}
String nextElement = nextLine[i];
if (nextElement == null)
continue;
if (quotechar != NO_QUOTE_CHARACTER)
sb.append(quotechar);
sb.append(stringContainsSpecialCharacters(nextElement) ? processLine(nextElement) : nextElement);
if (quotechar != NO_QUOTE_CHARACTER)
sb.append(quotechar);
}
sb.append(lineEnd);
pw.write(sb.toString());
}
private boolean stringContainsSpecialCharacters(String line) {
return line.indexOf(quotechar) != -1 || line.indexOf(escapechar) != -1;
}
protected StringBuilder processLine(String nextElement)
{
StringBuilder sb = new StringBuilder(INITIAL_STRING_SIZE);
for (int j = 0; j < nextElement.length(); j++) {
char nextChar = nextElement.charAt(j);
if (escapechar != NO_ESCAPE_CHARACTER && nextChar == quotechar) {
sb.append(escapechar).append(nextChar);
} else if (escapechar != NO_ESCAPE_CHARACTER && nextChar == escapechar) {
sb.append(escapechar).append(nextChar);
} else {
sb.append(nextChar);
}
}
return sb;
}
/**
* Flush underlying stream to writer.
*
* @throws IOException if bad things happen
*/
public void flush() throws IOException {
pw.flush();
}
/**
* Close the underlying stream writer flushing any buffered content.
*
* @throws IOException if bad things happen
*
*/
public void close() throws IOException {
flush();
pw.close();
rawWriter.close();
}
/**
* Checks to see if the there has been an error in the printstream.
*/
public boolean checkError() {
return pw.checkError();
}
public void setResultService(ResultSetHelper resultService) {
this.resultService = resultService;
}
}
/**
Copyright 2005 Bytecode Pty Ltd.
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.
*/
/**
* A very simple CSV parser released under a commercial-friendly license.
* This just implements splitting a single line into fields.
*
* @author Glen Smith
* @author Rainer Pruy
*
*/
class CSVParser {
private final char separator;
private final char quotechar;
private final char escape;
private final boolean strictQuotes;
private String pending;
private boolean inField = false;
private final boolean ignoreLeadingWhiteSpace;
/** The default separator to use if none is supplied to the constructor. */
public static final char DEFAULT_SEPARATOR = ',';
public static final int INITIAL_READ_SIZE = 128;
/**
* The default quote character to use if none is supplied to the
* constructor.
*/
public static final char DEFAULT_QUOTE_CHARACTER = '"';
/**
* The default escape character to use if none is supplied to the
* constructor.
*/
public static final char DEFAULT_ESCAPE_CHARACTER = '\\';
/**
* The default strict quote behavior to use if none is supplied to the
* constructor
*/
public static final boolean DEFAULT_STRICT_QUOTES = false;
/**
* The default leading whitespace behavior to use if none is supplied to the
* constructor
*/
public static final boolean DEFAULT_IGNORE_LEADING_WHITESPACE = true;
/**
* Constructs CSVParser using a comma for the separator.
*/
public CSVParser() {
this(DEFAULT_SEPARATOR, DEFAULT_QUOTE_CHARACTER, DEFAULT_ESCAPE_CHARACTER);
}
/**
* Constructs CSVParser with supplied separator.
* @param separator
* the delimiter to use for separating entries.
*/
public CSVParser(char separator) {
this(separator, DEFAULT_QUOTE_CHARACTER, DEFAULT_ESCAPE_CHARACTER);
}
/**
* Constructs CSVParser with supplied separator and quote char.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
*/
public CSVParser(char separator, char quotechar) {
this(separator, quotechar, DEFAULT_ESCAPE_CHARACTER);
}
/**
* Constructs CSVReader with supplied separator and quote char.
* @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 CSVParser(char separator, char quotechar, char escape) {
this(separator, quotechar, escape, DEFAULT_STRICT_QUOTES);
}
/**
* Constructs CSVReader with supplied separator and quote char.
* Allows setting the "strict quotes" flag
* @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 strictQuotes
* if true, characters outside the quotes are ignored
*/
public CSVParser(char separator, char quotechar, char escape, boolean strictQuotes) {
this(separator, quotechar, escape, strictQuotes, DEFAULT_IGNORE_LEADING_WHITESPACE);
}
/**
* Constructs CSVReader with supplied separator and quote char.
* Allows setting the "strict quotes" and "ignore leading whitespace" flags
* @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 strictQuotes
* if true, characters outside the quotes are ignored
* @param ignoreLeadingWhiteSpace
* if true, white space in front of a quote in a field is ignored
*/
public CSVParser(char separator, char quotechar, char escape, boolean strictQuotes, boolean ignoreLeadingWhiteSpace) {
this.separator = separator;
this.quotechar = quotechar;
this.escape = escape;
this.strictQuotes = strictQuotes;
this.ignoreLeadingWhiteSpace = ignoreLeadingWhiteSpace;
}
/**
*
* @return true if something was left over from last call(s)
*/
public boolean isPending() {
return pending != null;
}
public String[] parseLineMulti(String nextLine) throws IOException {
return parseLine(nextLine, true);
}
public String[] parseLine(String nextLine) throws IOException {
return parseLine(nextLine, false);
}
/**
* Parses an incoming String and returns an array of elements.
*
* @param nextLine
* the string to parse
* @param multi
* @return the comma-tokenized list of elements, or null if nextLine is null
* @throws IOException if bad things happen during the read
*/
private String[] parseLine(String nextLine, boolean multi) throws IOException {
if (!multi && pending != null) {
pending = null;
}
if (nextLine == null) {
if (pending != null) {
String s = pending;
pending = null;
return new String[] {s};
} else {
return null;
}
}
List<String>tokensOnThisLine = new ArrayList<String>();
StringBuilder sb = new StringBuilder(INITIAL_READ_SIZE);
boolean inQuotes = false;
if (pending != null) {
sb.append(pending);
pending = null;
inQuotes = true;
}
for (int i = 0; i < nextLine.length(); i++) {
char c = nextLine.charAt(i);
if (c == this.escape) {
if( isNextCharacterEscapable(nextLine, inQuotes || inField, i) ){
sb.append(nextLine.charAt(i+1));
i++;
}
} else if (c == quotechar) {
if( isNextCharacterEscapedQuote(nextLine, inQuotes || inField, i) ){
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 (!strictQuotes) {
if(i>2 //not on the beginning of the line
&& nextLine.charAt(i-1) != this.separator //not at the beginning of an escape sequence
&& nextLine.length()>(i+1) &&
nextLine.charAt(i+1) != this.separator //not at the end of an escape sequence
){
if (ignoreLeadingWhiteSpace && sb.length() > 0 && isAllWhiteSpace(sb)) {
sb = new StringBuilder(INITIAL_READ_SIZE); //discard white space leading up to quote
} else {
sb.append(c);
}
}
}
}
inField = !inField;
} else if (c == separator && !inQuotes) {
tokensOnThisLine.add(sb.toString());
sb = new StringBuilder(INITIAL_READ_SIZE); // start work on next token
inField = false;
} else {
if (!strictQuotes || inQuotes){
sb.append(c);
inField = true;
}
}
}
// line is done - check status
if (inQuotes) {
if (multi) {
// continuing a quoted section, re-append newline
sb.append("\n");
pending = sb.toString();
sb = null; // this partial content is not to be added to field list yet
} else {
throw new IOException("Un-terminated quoted field at end of CSV line");
}
}
if (sb != null) {
tokensOnThisLine.add(sb.toString());
}
return tokensOnThisLine.toArray(new String[tokensOnThisLine.size()]);
}
/**
* precondition: the current character is a quote or an escape
* @param nextLine the current line
* @param inQuotes true if the current context is quoted
* @param i current index in line
* @return true if the following character is a quote
*/
private boolean isNextCharacterEscapedQuote(String nextLine, boolean inQuotes, int i) {
return inQuotes // we are in quotes, therefore there can be escaped quotes in here.
&& nextLine.length() > (i+1) // there is indeed another character to check.
&& nextLine.charAt(i+1) == quotechar;
}
/**
* precondition: the current character is an escape
* @param nextLine the current line
* @param inQuotes true if the current context is quoted
* @param i current index in line
* @return true if the following character is a quote
*/
protected boolean isNextCharacterEscapable(String nextLine, boolean inQuotes, int i) {
return inQuotes // we are in quotes, therefore there can be escaped quotes in here.
&& nextLine.length() > (i+1) // there is indeed another character to check.
&& ( nextLine.charAt(i+1) == quotechar || nextLine.charAt(i+1) == this.escape);
}
/**
* precondition: sb.length() > 0
* @param sb A sequence of characters to examine
* @return true if every character in the sequence is whitespace
*/
protected boolean isAllWhiteSpace(CharSequence sb) {
boolean result = true;
for (int i = 0; i < sb.length(); i++) {
char c = sb.charAt(i);
if ( !Character.isWhitespace(c) ) {
return false;
}
}
return result;
}
}
/**
Copyright 2005 Bytecode Pty Ltd.
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.
*/
/**
*
*
* helper class for processing JDBC ResultSet objects
*
*
*/
class ResultSetHelperService implements ResultSetHelper {
public static final int CLOBBUFFERSIZE = 2048;
// note: we want to maintain compatibility with Java 5 VM's
// These types don't exist in Java 5
private static final int NVARCHAR = -9;
private static final int NCHAR = -15;
private static final int LONGNVARCHAR = -16;
private static final int NCLOB = 2011;
public String[] getColumnNames(ResultSet rs) throws SQLException {
List<String> names = new ArrayList<String>();
ResultSetMetaData metadata = rs.getMetaData();
for (int i = 0; i < metadata.getColumnCount(); i++) {
names.add(metadata.getColumnName(i+1));
}
String[] nameArray = new String[names.size()];
return names.toArray(nameArray);
}
public String[] getColumnValues(ResultSet rs) throws SQLException, IOException {
List<String> values = new ArrayList<String>();
ResultSetMetaData metadata = rs.getMetaData();
for (int i = 0; i < metadata.getColumnCount(); i++) {
values.add(getColumnValue(rs, metadata.getColumnType(i + 1), i + 1));
}
String[] valueArray = new String[values.size()];
return values.toArray(valueArray);
}
private String handleObject(Object obj){
return obj == null ? "" : String.valueOf(obj);
}
private String handleBigDecimal(BigDecimal decimal) {
return decimal == null ? "" : decimal.toString();
}
private String handleLong(ResultSet rs, int columnIndex) throws SQLException {
long lv = rs.getLong(columnIndex);
return rs.wasNull() ? "" : Long.toString(lv);
}
private String handleInteger(ResultSet rs, int columnIndex) throws SQLException {
int i = rs.getInt(columnIndex);
return rs.wasNull() ? "" : Integer.toString(i);
}
private String handleDate(ResultSet rs, int columnIndex) throws SQLException {
java.sql.Date date = rs.getDate(columnIndex);
String value = null;
if (date != null) {
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy");
value = dateFormat.format(date);
}
return value;
}
private String handleTime(Time time) {
return time == null ? null : time.toString();
}
private String handleTimestamp(Timestamp timestamp) {
SimpleDateFormat timeFormat = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss");
return timestamp == null ? null : timeFormat.format(timestamp);
}
private String getColumnValue(ResultSet rs, int colType, int colIndex)
throws SQLException, IOException {
String value = "";
switch (colType)
{
case Types.BIT:
case Types.JAVA_OBJECT:
value = handleObject(rs.getObject(colIndex));
break;
case Types.BOOLEAN:
boolean b = rs.getBoolean(colIndex);
value = Boolean.valueOf(b).toString();
break;
case NCLOB: // todo : use rs.getNClob
case Types.CLOB:
Clob c = rs.getClob(colIndex);
if (c != null) {
value = read(c);
}
break;
case Types.BIGINT:
value = handleLong(rs, colIndex);
break;
case Types.DECIMAL:
case Types.DOUBLE:
case Types.FLOAT:
case Types.REAL:
case Types.NUMERIC:
value = handleBigDecimal(rs.getBigDecimal(colIndex));
break;
case Types.INTEGER:
case Types.TINYINT:
case Types.SMALLINT:
value = handleInteger(rs, colIndex);
break;
case Types.DATE:
value = handleDate(rs, colIndex);
break;
case Types.TIME:
value = handleTime(rs.getTime(colIndex));
break;
case Types.TIMESTAMP:
value = handleTimestamp(rs.getTimestamp(colIndex));
break;
case NVARCHAR: // todo : use rs.getNString
case NCHAR: // todo : use rs.getNString
case LONGNVARCHAR: // todo : use rs.getNString
case Types.LONGVARCHAR:
case Types.VARCHAR:
case Types.CHAR:
value = rs.getString(colIndex);
break;
default:
value = "";
}
if (value == null)
{
value = "";
}
return value;
}
private static String read(Clob c) throws SQLException, IOException
{
StringBuilder sb = new StringBuilder( (int) c.length());
Reader r = c.getCharacterStream();
char[] cbuf = new char[CLOBBUFFERSIZE];
int n;
while ((n = r.read(cbuf, 0, cbuf.length)) != -1) {
sb.append(cbuf, 0, n);
}
return sb.toString();
}
}
interface ResultSetHelper {
public String[] getColumnNames(ResultSet rs) throws SQLException;
public String[] getColumnValues(ResultSet rs) throws SQLException, IOException;
}
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