csvprinter.java

java操作excel的类

		}
	}

	/**
	 * Print a single line of comma separated values.
	 * The values will be quoted if needed.  Quotes and
	 * and other characters that need it will be escaped.
	 *
	 * @param values values to be outputted.
	 * @throws IOException if an error occurs while writing.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void write(String[] values) throws IOException {
		try {
			for (int i=0; i<values.length; i++){
				write(values[i]);
			}
		} catch (IOException iox){
			error = true;
			throw iox;
		}
	}

	/**
	 * Print several lines of comma separated values.
	 * The values will be quoted if needed.  Quotes and
	 * newLine characters will be escaped.
	 * <p>
	 * This method never throws an I/O exception. The client may inquire as to whether
	 * any errors have occurred by invoking checkError().  If an I/O Exception is
	 * desired, the client should use the corresponding writeln method.
	 *
	 * @param values values to be outputted.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public void println(String[][] values){
		try {
			writeln(values);
		} catch (IOException iox){
			error = true;
		}
	}

	/**
	 * Print several lines of comma separated values.
	 * The values will be quoted if needed.  Quotes and
	 * newLine characters will be escaped.
	 *
	 * @param values values to be outputted.
	 * @throws IOException if an error occurs while writing.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void writeln(String[][] values) throws IOException {
		try {
			for (int i=0; i<values.length; i++){
				writeln(values[i]);
			}
			if (values.length == 0){
				writeln();
			}
		} catch (IOException iox){
			error = true;
			throw iox;
		}
	}

	/**
	 * Put a comment among the comma separated values.
	 * Comments will always begin on a new line and occupy a
	 * least one full line. The character specified to star
	 * comments and a space will be inserted at the beginning of
	 * each new line in the comment.  If the comment is null,
	 * an empty comment is outputted.
	 * <p>
	 * This method never throws an I/O exception. The client may inquire as to whether
	 * any errors have occurred by invoking checkError().  If an I/O Exception is
	 * desired, the client should use the corresponding writelnComment method.
	 *
	 * @param comment the comment to output.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public void printlnComment(String comment){
		try {
			writelnComment(comment);
		} catch (IOException iox){
			error = true;
		}
	}

	/**
	 * Put a comment among the comma separated values.
	 * Comments will always begin on a new line and occupy a
	 * least one full line. The character specified to star
	 * comments and a space will be inserted at the beginning of
	 * each new line in the comment.  If the comment is null,
	 * an empty comment is outputted.
	 *
	 * @param comment the comment to output.
	 * @throws IOException if an error occurs while writing.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void writelnComment(String comment) throws IOException {
		try {
			if (comment==null) comment = "";
			if (!newLine){
				writeln();
			}
			out.write(commentStart);
			out.write(' ');
			for (int i=0; i<comment.length(); i++){
				char c = comment.charAt(i);
				switch (c){
					case '\r': {
						if (i+1 < comment.length() && comment.charAt(i+1) == '\n'){
							i++;
						}
					} //break intentionally excluded.
					case '\n': {
						writeln();
						out.write(commentStart);
						out.write(' ');
					} break;
					default: {
						out.write(c);
					} break;
				}
			}
			writeln();
		} catch (IOException iox){
			error = true;
			throw iox;
		}
	}

	/**
	 * Print the string as the next value on the line.	The value
	 * will be quoted if needed.  If value is null, an empty value is printed.
	 * <p>
	 * This method never throws an I/O exception. The client may inquire as to whether
	 * any errors have occurred by invoking checkError().  If an I/O Exception is
	 * desired, the client should use the corresponding println method.
	 *
	 * @param value value to be outputted.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public void print(String value){
		try {
			write(value);
		} catch (IOException iox){
			error = true;
		}
	}

	/**
	 * Print the string as the next value on the line.	The value
	 * will be quoted if needed.  If value is null, an empty value is printed.
	 *
	 * @param value value to be outputted.
	 * @throws IOException if an error occurs while writing.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void write(String value) throws IOException {
		try {
			if (value == null) value = "";
			boolean quote = false;
			if (alwaysQuote){
				quote = true;
			} else if (value.length() > 0){
				char c = value.charAt(0);
				if (newLine && (c<'0' || (c>'9' && c<'A') || (c>'Z' && c<'a') || (c>'z'))){
					quote = true;
				}
				if (c==' ' || c=='\f' || c=='\t'){
					quote = true;
				}
				for (int i=0; i<value.length(); i++){
					c = value.charAt(i);
					if (c==quoteChar || c==delimiterChar || c=='\n' || c=='\r'){
						quote = true;
					}
				}
				if (c==' ' || c=='\f' || c=='\t'){
					quote = true;
				}
			} else if (newLine) {
				// always quote an empty token that is the first
				// on the line, as it may be the only thing on the
				// line.  If it were not quoted in that case,
				// an empty line has no tokens.
				quote = true;
			}
			if (newLine){
				newLine = false;
			} else {
				out.write(delimiterChar);
			}
			if (quote){
				out.write(escapeAndQuote(value));
			} else {
				out.write(value);
			}
			if (autoFlush) flush();
		} catch (IOException iox){
			error = true;
			throw iox;
		}
	}

	/**
	 * Enclose the value in quotes and escape the quote
	 * and comma characters that are inside.
	 *
	 * @param value needs to be escaped and quoted
	 * @return the value, escaped and quoted.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	private String escapeAndQuote(String value){
		int count = 2;
		for (int i=0; i<value.length(); i++){
			char c = value.charAt(i);
			switch(c){
				case '\n': case '\r': case '\\': {
					count ++;
				} break;
				default: {
					if (c == quoteChar){
						count++;
					}
				} break;
			}
		}
		StringBuffer sb = new StringBuffer(value.length() + count);
		sb.append(quoteChar);
		for (int i=0; i<value.length(); i++){
			char c = value.charAt(i);
			switch(c){
				case '\n': {
					sb.append("\\n");
				} break;
				case '\r': {
					sb.append("\\r");
				} break;
				case '\\': {
					sb.append("\\\\");
				} break;
				default: {
					if (c == quoteChar){
						sb.append("\\" + quoteChar);
					} else {
						sb.append(c);
					}
				}
			}
		}
		sb.append(quoteChar);
		return (sb.toString());
	}

	/**
	 * Flush any data written out to underlying streams.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void flush() throws IOException {
		out.flush();
	}

	/**
	 * Close any underlying streams.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void close() throws IOException {
		out.close();
	}

	/**
	 * Flush the stream if it's not closed and check its error state.
	 * Errors are cumulative; once the stream encounters an error,
	 * this routine will return true on all successive calls.
	 *
	 * @return True if the print stream has encountered an error,
	 * either on the underlying output stream or during a format conversion.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public boolean checkError(){
		try {
			if (error) return true;
			flush();
			if (error) return true;
			if (out instanceof PrintWriter){
				error = ((PrintWriter)out).checkError();
			}
		} catch (IOException iox){
			error = true;
		}
		return error;
	}

	/**
	 * Set flushing behavior.  Iff set, a flush command
	 * will be issued to any underlying stream after each
	 * print or write command.
	 *
	 * @param autoFlush should auto flushing be enabled.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void setAutoFlush(boolean autoFlush){
		this.autoFlush = autoFlush;
	}

	/**
	 * Set whether values printers should always be quoted, or
	 * whether the printer may, at its discretion, omit quotes
	 * around the value.
	 *
	 * @param alwaysQuote true if quotes should be used even when not strictly needed.
	 *
	 * @since ostermillerutils 1.02.26
	 */
	public void setAlwaysQuote(boolean alwaysQuote){
		this.alwaysQuote = alwaysQuote;
	}

	/**
	 * Write some test data to the given file.
	 *
	 * @param args First argument is the file name.  System.out used if no filename given.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	private static void main(String[] args) {
		OutputStream out;
		try {
			if (args.length > 0){
				File f = new File(args[0]);
				if (!f.exists()){
						f.createNewFile();
					if (f.canWrite()){
						out = new FileOutputStream(f);
					} else {
						throw new IOException("Could not open " + args[0]);
					}
				} else {
					throw new IOException("File already exists: " + args[0]);
				}
			} else {
				out = System.out;
			}
			CSVPrinter p  = new CSVPrinter(out);
			p.print("unquoted");
			p.print("un\\quoted");
			p.print("escaped\"quote");
			p.print("escaped\"quote\\");
			p.println("comma,comma");
			p.print("!quoted");
			p.print("!unquoted");
			p.print(" quoted");
			p.print("quoted ");
			p.printlnComment("A comment.");
			p.print("one");
			p.print("");
			p.print("");
			p.print("");
			p.print("");
			p.printlnComment("Multi\nLine\rComment\r\nto test line breaks\r");
			p.println("two");
			p.printlnComment("Comment after explicit new line.");
			p.print("\nthree\nline\n");
			p.println("\ttab");
		} catch (IOException e){
			System.out.println(e.getMessage());
		}
	}
}