WebResultCSVFormatter.java

package ca.sqlpower.sql;

import java.io.PrintWriter;
import java.sql.SQLException;
import java.text.StringCharacterIterator;

public class WebResultCSVFormatter extends WebResultFormatter {
    public WebResultCSVFormatter() {
	super();
    }

    public void formatToStream(WebResultSet wrs, PrintWriter out) 
	throws SQLException, NoRowidException, IllegalStateException {
		formatHeader(wrs,out);
		formatBody(wrs,out);
    }

	public void formatHeader(WebResultSet wrs, PrintWriter out) throws SQLException {
		int numCols=wrs.getColumnCount();
		StringBuffer sb=new StringBuffer(256);
		boolean thisIsTheFirstColumn = true;
		for (int i = 1; i <= numCols; i++) {

			if (columnNotAppropriate(wrs, i)) {
				continue;
			}

			sb.setLength(0);
			try {
				if (!thisIsTheFirstColumn) {
					sb.append(",");
				}

				sb.append(
					makeStringSafe(beautifyHeading(wrs.getColumnLabel(i))));
				out.print(sb);
				thisIsTheFirstColumn = false;
			} catch (ColumnNotDisplayableException e) {
				// Column didn't get printed (which is good)
			}
		}
		out.println("");
	}

	public void formatBody(WebResultSet wrs, PrintWriter out)
		throws SQLException, NoRowidException {
		int numCols=wrs.getColumnCount();
		StringBuffer contents=new StringBuffer(256);
		StringBuffer align=new StringBuffer(32);
		while (wrs.next()) {
			boolean thisIsTheFirstColumn = true;
			for (int i = 1; i <= numCols; i++) {

				if (columnNotAppropriate(wrs, i)) {
					continue;
				}

				contents.setLength(0);
				align.setLength(0);
				try {
					getColumnFormatted(wrs, i, contents, align);
					if (!thisIsTheFirstColumn) {
						out.print(",");
					}
					out.print(makeStringSafe(contents.toString()));
					thisIsTheFirstColumn = false;
				} catch (ColumnNotDisplayableException e) {
					// Column didn't get printed (which is good)
				} catch (UnsupportedOperationException e) {
					// Column didn't get printed, but we wanted it to
					out.print(makeStringSafe(wrs.getString(i)));
				}
			}
			out.println("");
		}
	}


    /**
     * Makes a CSV-file-safe version of a given string.  This includes
     * escaping CR, LF, and double-quote characters with backslashes,
     * and quoting strings that contain whitespace.
     *
     * @param original The original, unsafe string.
     * @return The original string if it contained none of the special
     * characters mentioned above; an empty string if the original was
     * null; otherwise, a quoted version of the original string with
     * the necessary characters backslash-escaped.
     */
    public static String makeStringSafe(String original) {
	if(original==null) {
	    return "";
	}


	StringBuffer escaped = new StringBuffer(original.length());
	StringCharacterIterator it = new StringCharacterIterator(original);
	boolean escapedDiffersFromOriginal=false;
	char ch;
	
	escaped.append("\"");
	
	do {
	    ch=it.current();
	    switch(ch) {
	    case '\n':
		escaped.append("\\n");
		escapedDiffersFromOriginal=true;
		break;
		
	    case '\r':
		escaped.append("\\r");
		escapedDiffersFromOriginal=true;
		break;
		
 	    case '"':
		escaped.append("\\\"");
		escapedDiffersFromOriginal=true;
		break;

	    case '\\':
		escaped.append("\\\\");
		escapedDiffersFromOriginal=true;
		break;

	    case ' ':
	    case '\f':
	    case '\t':
	    case ',':
		// Whitespace and commas don't need to be escaped
		// explicitly, but the whole string will need to be
		// quoted.
		escaped.append(ch);
		escapedDiffersFromOriginal=true;
		break;

	    default:
		escaped.append(ch);
		break;
	    }
	} while( it.next() != StringCharacterIterator.DONE);
	
	escaped.append("\"");
	
	return (escapedDiffersFromOriginal ? escaped.toString() : original);
    }

    protected boolean columnNotAppropriate(WebResultSet wrs, int colNo) {
/*		if(wrs.getColumnHyperlinks(colNo) != null) {
			return true;
		} */
		int ctype=wrs.getColumnType(colNo);
		switch(ctype) {
		case FieldTypes.RADIO:
		case FieldTypes.CHECKBOX:
		case FieldTypes.ROWID:
		case FieldTypes.DUMMY:
		case FieldTypes.MUTEX_CHECKBOX:
			return true;

		default:
			return false;
		}
    }
    
    
    
	/**
	 * @see ca.sqlpower.sql.WebResultFormatter#getColumnFormatted(WebResultSet, int, StringBuffer, StringBuffer)
	 */
	protected void getColumnFormatted(
		WebResultSet wrs,
		int i,
		StringBuffer contents,
		StringBuffer align)
		throws
			SQLException,
			NoRowidException,
			ColumnNotDisplayableException,
			IllegalStateException {
	
			java.sql.ResultSetMetaData md = wrs.getRsmd();
			switch (md.getColumnType(i)) {
				case java.sql.Types.TIMESTAMP:
	       		    java.sql.Date tsDate=wrs.getDate(i);
		            if(tsDate==null) {
		                // leave empty
		            } else {
		                contents.append(
	                    dateFormatter.format(new java.util.Date(tsDate.getTime())));
    		        }
    		        break;
				default:
					contents.append(wrs.getString(i));		
			}
	}

}