com.day.text.csv.Csv Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of aem-sdk-api Show documentation
Show all versions of aem-sdk-api Show documentation
The Adobe Experience Manager SDK
/*************************************************************************
*
* ADOBE CONFIDENTIAL
* __________________
*
* Copyright 2012 Adobe Systems Incorporated
* All Rights Reserved.
*
* NOTICE: All information contained herein is, and remains
* the property of Adobe Systems Incorporated and its suppliers,
* if any. The intellectual and technical concepts contained
* herein are proprietary to Adobe Systems Incorporated and its
* suppliers and are protected by trade secret or copyright law.
* Dissemination of this information or reproduction of this material
* is strictly forbidden unless prior written permission is obtained
* from Adobe Systems Incorporated.
**************************************************************************/
package com.day.text.csv;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Iterator;
/**
* A facility to read from and write to CSV (comma separated values) files.
*
* This is a simplified version of the CSV tool of the H2 database:
* http://code.google.com/p/h2database/source/browse/trunk/h2/src/main/org/h2/tools/Csv.java
* (also written by Thomas Mueller)
*
* @author Thomas Mueller
*/
public class Csv {
private static final int IO_BUFFER_SIZE = 4 * 1024;
private char fieldSeparatorRead = ',';
private char commentLineStart = '#';
private String fieldSeparatorWrite = ",";
private String rowSeparatorWrite;
private char fieldDelimiter = '\"';
private char escapeCharacter = '\"';
private String lineSeparator = System.getProperty("line.separator");
private String nullString = "";
private Reader input;
private char[] inputBuffer;
private int inputBufferPos;
private int inputBufferStart = -1;
private int inputBufferEnd;
private Writer output;
private boolean endOfLine, endOfFile;
/**
* Reads from the CSV file and returns an iterator. The rows in the result
* set are created on demand, that means the file is kept open until all
* rows are read or the CSV tool is closed.
*
* Depending on the contents of the file, the first line of the result may
* or may not contain the column names.
*
* @param in the input stream
* @param charset the charset or null to use the system default charset (see
* system property file.encoding)
* @return the iterator
* @throws IOException
*/
public Iterator read(InputStream in, String charset) throws IOException {
if (charset == null) {
charset = System.getProperty("file.encoding");
}
in = new BufferedInputStream(in, IO_BUFFER_SIZE);
input = new InputStreamReader(in, charset);
return read();
}
/**
* Reads from the CSV file and returns an iterator. The rows in the result
* set are created on demand, that means the file is kept open until all
* rows are read or the CSV tool is closed.
*
* Depending on the contents of the file, the first line of the result may
* or may not contain the column names.
*
* @param reader the reader
* @return the iterator
* @throws IOException
*/
public Iterator read(Reader reader) throws IOException {
if (!(reader instanceof BufferedReader)) {
reader = new BufferedReader(reader);
}
input = reader;
return read();
}
private Iterator read() throws IOException {
inputBuffer = new char[IO_BUFFER_SIZE * 2];
return new RowIterator();
}
/**
* Initialize writing.
*
* @param out the output stream
* @param charset the character set or null
*/
public void writeInit(OutputStream out, String charset) throws IOException {
if (charset == null) {
charset = System.getProperty("file.encoding");
}
out = new BufferedOutputStream(out, IO_BUFFER_SIZE);
output = new BufferedWriter(new OutputStreamWriter(out, charset));
}
/**
* Initialize writing.
*
* @param writer the writer
*/
public void writeInit(Writer writer) throws IOException {
if (!(writer instanceof BufferedWriter)) {
writer = new BufferedWriter(writer);
}
output = writer;
}
/**
* Write a row.
*
* @param values the values
*/
public void writeRow(String... values) throws IOException {
for (int i = 0; i < values.length; i++) {
if (i > 0) {
if (fieldSeparatorWrite != null) {
output.write(fieldSeparatorWrite);
}
}
String s = values[i];
if (s != null) {
if (escapeCharacter != 0) {
if (fieldDelimiter != 0) {
output.write(fieldDelimiter);
}
output.write(escape(s));
if (fieldDelimiter != 0) {
output.write(fieldDelimiter);
}
} else {
output.write(s);
}
} else if (nullString != null && nullString.length() > 0) {
output.write(nullString);
}
}
if (rowSeparatorWrite != null) {
output.write(rowSeparatorWrite);
}
output.write(lineSeparator);
}
private String escape(String data) {
if (data.indexOf(fieldDelimiter) < 0) {
if (escapeCharacter == fieldDelimiter || data.indexOf(escapeCharacter) < 0) {
return data;
}
}
StringBuilder buff = new StringBuilder(data.length());
for (int i = 0; i < data.length(); i++) {
char ch = data.charAt(i);
if (ch == fieldDelimiter || ch == escapeCharacter) {
buff.append(escapeCharacter);
}
buff.append(ch);
}
return buff.toString();
}
private void pushBack() {
inputBufferPos--;
}
private int readChar() throws IOException {
if (inputBufferPos >= inputBufferEnd) {
return readBuffer();
}
return inputBuffer[inputBufferPos++];
}
private int readBuffer() throws IOException {
if (endOfFile) {
return -1;
}
int keep;
if (inputBufferStart >= 0) {
keep = inputBufferPos - inputBufferStart;
if (keep > 0) {
char[] src = inputBuffer;
if (keep + IO_BUFFER_SIZE > src.length) {
inputBuffer = new char[src.length * 2];
}
System.arraycopy(src, inputBufferStart, inputBuffer, 0, keep);
}
inputBufferStart = 0;
} else {
keep = 0;
}
inputBufferPos = keep;
int len = input.read(inputBuffer, keep, IO_BUFFER_SIZE);
if (len == -1) {
// ensure bufferPos > bufferEnd
// even after pushBack
inputBufferEnd = -1024;
endOfFile = true;
// ensure the right number of characters are read
// in case the input buffer is still used
inputBufferPos++;
return -1;
}
inputBufferEnd = keep + len;
return inputBuffer[inputBufferPos++];
}
private String readValue() throws IOException {
endOfLine = false;
inputBufferStart = inputBufferPos;
while (true) {
int ch = readChar();
if (ch == fieldDelimiter) {
// delimited value
boolean containsEscape = false;
inputBufferStart = inputBufferPos;
int sep;
while (true) {
ch = readChar();
if (ch == fieldDelimiter) {
ch = readChar();
if (ch != fieldDelimiter) {
sep = 2;
break;
}
containsEscape = true;
} else if (ch == escapeCharacter) {
ch = readChar();
if (ch < 0) {
sep = 1;
break;
}
containsEscape = true;
} else if (ch < 0) {
sep = 1;
break;
}
}
String s = new String(inputBuffer, inputBufferStart, inputBufferPos - inputBufferStart - sep);
if (containsEscape) {
s = unEscape(s);
}
inputBufferStart = -1;
while (true) {
if (ch == fieldSeparatorRead) {
break;
} else if (ch == '\n' || ch < 0 || ch == '\r') {
endOfLine = true;
break;
} else if (ch == ' ' || ch == '\t') {
// ignore
} else {
pushBack();
break;
}
ch = readChar();
}
return s;
} else if (ch == '\n' || ch < 0 || ch == '\r') {
endOfLine = true;
return null;
} else if (ch == fieldSeparatorRead) {
// null
return null;
} else if (ch <= ' ') {
// ignore spaces
continue;
} else if (ch == commentLineStart) {
// comment until end of line
inputBufferStart = -1;
while (true) {
ch = readChar();
if (ch == '\n' || ch < 0 || ch == '\r') {
break;
}
}
endOfLine = true;
return null;
} else {
// un-delimited value
while (true) {
ch = readChar();
if (ch == fieldSeparatorRead) {
break;
} else if (ch == '\n' || ch < 0 || ch == '\r') {
endOfLine = true;
break;
}
}
String s = new String(inputBuffer, inputBufferStart, inputBufferPos - inputBufferStart - 1);
inputBufferStart = -1;
// check un-delimited value for nullString
return readNull(s.trim());
}
}
}
private String readNull(String s) {
return s.equals(nullString) ? null : s;
}
private String unEscape(String s) {
StringBuilder buff = new StringBuilder(s.length());
int start = 0;
char[] chars = null;
while (true) {
int idx = s.indexOf(escapeCharacter, start);
if (idx < 0) {
idx = s.indexOf(fieldDelimiter, start);
if (idx < 0) {
break;
}
}
if (chars == null) {
chars = s.toCharArray();
}
buff.append(chars, start, idx - start);
if (idx == s.length() - 1) {
start = s.length();
break;
}
buff.append(chars[idx + 1]);
start = idx + 2;
}
buff.append(s.substring(start));
return buff.toString();
}
private String[] readRow() {
if (input == null) {
return null;
}
ArrayList row = new ArrayList();
try {
int i = 0;
while (true) {
String v = readValue();
if (v == null) {
v = this.nullString;
if (endOfLine) {
if (i == 0) {
if (endOfFile) {
return null;
}
// empty line
continue;
}
break;
}
}
row.add(v);
i++;
if (endOfLine) {
break;
}
}
} catch (IOException e) {
throw new RuntimeException("IOException while reading", e);
}
return row.toArray(new String[row.size()]);
}
/**
* Close all streams. Exceptions are ignored.
*/
public void close() throws IOException {
if (input != null) {
input.close();
input = null;
}
if (output != null) {
output.close();
output = null;
}
}
/**
* Override the field separator for writing. The default is ",".
*
* @param fieldSeparatorWrite the field separator
*/
public void setFieldSeparatorWrite(String fieldSeparatorWrite) {
this.fieldSeparatorWrite = fieldSeparatorWrite;
}
/**
* Get the current field separator for writing.
*
* @return the field separator
*/
public String getFieldSeparatorWrite() {
return fieldSeparatorWrite;
}
/**
* Override the field separator for reading. The default is ','.
*
* @param fieldSeparatorRead the field separator
*/
public void setFieldSeparatorRead(char fieldSeparatorRead) {
this.fieldSeparatorRead = fieldSeparatorRead;
}
/**
* Get the current field separator for reading.
*
* @return the field separator
*/
public char getFieldSeparatorRead() {
return fieldSeparatorRead;
}
/**
* Get the current row separator for writing.
*
* @return the row separator
*/
public String getRowSeparatorWrite() {
return rowSeparatorWrite;
}
/**
* Override the end-of-row marker for writing. The default is null. After
* writing the end-of-row marker, a line feed is written (\n or \r\n
* depending on the system settings).
*
* @param rowSeparatorWrite the row separator
*/
public void setRowSeparatorWrite(String rowSeparatorWrite) {
this.rowSeparatorWrite = rowSeparatorWrite;
}
/**
* Set the field delimiter. The default is " (a double quote).
* The value 0 means no field delimiter is used.
*
* @param fieldDelimiter the field delimiter
*/
public void setFieldDelimiter(char fieldDelimiter) {
this.fieldDelimiter = fieldDelimiter;
}
/**
* Get the current field delimiter.
*
* @return the field delimiter
*/
public char getFieldDelimiter() {
return fieldDelimiter;
}
/**
* Set the escape character (used to escape the field delimiter). The
* default is " (a double quote). The value 0 means no escape character is used.
*
* @param escapeCharacter the escape character
*/
public void setEscapeCharacter(char escapeCharacter) {
this.escapeCharacter = escapeCharacter;
}
/**
* Get the current escape character.
*
* @return the escape character
*/
public char getEscapeCharacter() {
return escapeCharacter;
}
/**
* Set the line separator.
*
* @param lineSeparator the line separator
*/
public void setLineSeparator(String lineSeparator) {
this.lineSeparator = lineSeparator;
}
/**
* Set the value that represents NULL. The default is an empty string.
*
* @param nullString the null
*/
public void setNullString(String nullString) {
this.nullString = nullString;
}
/**
* Get the current null string.
*
* @return the null string.
*/
public String getNullString() {
return nullString;
}
class RowIterator implements Iterator {
private String[] current;
RowIterator() {
readNext();
}
private void readNext() {
current = readRow();
}
public boolean hasNext() {
return current != null;
}
public String[] next() {
String[] r = current;
readNext();
return r;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy