Java tutorial
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See the License for the specific language governing permissions and limitations under the License. ==================================================================== */ package com.teradata.demo.utils.excel; import org.apache.poi.ss.usermodel.BuiltinFormats; import org.apache.poi.ss.usermodel.DataFormatter; import org.apache.poi.xssf.eventusermodel.ReadOnlySharedStringsTable; import org.apache.poi.xssf.model.StylesTable; import org.apache.poi.xssf.usermodel.XSSFCellStyle; import org.apache.poi.xssf.usermodel.XSSFRichTextString; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; /** * This class handles the processing of a sheet#.xml * sheet part of a XSSF .xlsx file, and generates * row and cell events for it. */ public class XSSFSheetXMLHandler extends DefaultHandler { /** * These are the different kinds of cells we support. * We keep track of the current one between * the start and end. */ enum xssfDataType { BOOLEAN, ERROR, FORMULA, INLINE_STRING, SST_STRING, NUMBER, } /** * Table with the styles used for formatting */ private StylesTable stylesTable; private ReadOnlySharedStringsTable sharedStringsTable; /** * Where our text is going */ private final SheetContentsHandler output; // Set when V start element is seen private boolean vIsOpen; // Set when F start element is seen private boolean fIsOpen; // Set when an Inline String "is" is seen private boolean isIsOpen; // Set when a header/footer element is seen private boolean hfIsOpen; // Set when cell start element is seen; // used when cell close element is seen. private xssfDataType nextDataType; // Used to format numeric cell values. private short formatIndex; private String formatString; private final DataFormatter formatter; private String cellRef; private boolean formulasNotResults; // Gathers characters as they are seen. private StringBuffer value = new StringBuffer(); private StringBuffer formula = new StringBuffer(); private StringBuffer headerFooter = new StringBuffer(); /** * Accepts objects needed while parsing. * * @param styles Table of styles * @param strings Table of shared strings */ public XSSFSheetXMLHandler(StylesTable styles, ReadOnlySharedStringsTable strings, SheetContentsHandler sheetContentsHandler, DataFormatter dataFormatter, boolean formulasNotResults) { this.stylesTable = styles; this.sharedStringsTable = strings; this.output = sheetContentsHandler; this.formulasNotResults = formulasNotResults; this.nextDataType = xssfDataType.NUMBER; this.formatter = dataFormatter; } /** * Accepts objects needed while parsing. * * @param styles Table of styles * @param strings Table of shared strings */ public XSSFSheetXMLHandler(StylesTable styles, ReadOnlySharedStringsTable strings, SheetContentsHandler sheetContentsHandler, boolean formulasNotResults) { this(styles, strings, sheetContentsHandler, new DataFormatter(), formulasNotResults); } private boolean isTextTag(String name) { if ("v".equals(name)) { // Easy, normal v text tag return true; } if ("inlineStr".equals(name)) { // Easy inline string return true; } if ("t".equals(name) && isIsOpen) { // Inline string <is><t>...</t></is> pair return true; } // It isn't a text tag return false; } public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException { if (isTextTag(name)) { vIsOpen = true; // Clear contents cache value.setLength(0); } else if ("is".equals(name)) { // Inline string outer tag isIsOpen = true; } else if ("f".equals(name)) { // Clear contents cache formula.setLength(0); // Mark us as being a formula if not already if (nextDataType == xssfDataType.NUMBER) { nextDataType = xssfDataType.FORMULA; } // Decide where to get the formula string from String type = attributes.getValue("t"); if (type != null && type.equals("shared")) { // Is it the one that defines the shared, or uses it? String ref = attributes.getValue("ref"); String si = attributes.getValue("si"); if (ref != null) { // This one defines it // TODO Save it somewhere fIsOpen = true; } else { // This one uses a shared formula // TODO Retrieve the shared formula and tweak it to // match the current cell if (formulasNotResults) { System.err.println("Warning - shared formulas not yet supported!"); } else { // It's a shared formula, so we can't get at the formula string yet // However, they don't care about the formula string, so that's ok! } } } else { fIsOpen = true; } } else if ("oddHeader".equals(name) || "evenHeader".equals(name) || "firstHeader".equals(name) || "firstFooter".equals(name) || "oddFooter".equals(name) || "evenFooter".equals(name)) { hfIsOpen = true; // Clear contents cache headerFooter.setLength(0); } else if ("row".equals(name)) { int rowNum = Integer.parseInt(attributes.getValue("r")) - 1; output.startRow(rowNum); } // c => cell else if ("c".equals(name)) { // Set up defaults. this.nextDataType = xssfDataType.NUMBER; this.formatIndex = -1; this.formatString = null; cellRef = attributes.getValue("r"); String cellType = attributes.getValue("t"); String cellStyleStr = attributes.getValue("s"); if ("b".equals(cellType)) nextDataType = xssfDataType.BOOLEAN; else if ("e".equals(cellType)) nextDataType = xssfDataType.ERROR; else if ("inlineStr".equals(cellType)) nextDataType = xssfDataType.INLINE_STRING; else if ("s".equals(cellType)) nextDataType = xssfDataType.SST_STRING; else if ("str".equals(cellType)) nextDataType = xssfDataType.FORMULA; else if (cellStyleStr != null) { // Number, but almost certainly with a special style or format int styleIndex = Integer.parseInt(cellStyleStr); XSSFCellStyle style = stylesTable.getStyleAt(styleIndex); this.formatIndex = style.getDataFormat(); this.formatString = style.getDataFormatString(); if (this.formatString == null) this.formatString = BuiltinFormats.getBuiltinFormat(this.formatIndex); } } } public void endElement(String uri, String localName, String name) throws SAXException { String thisStr = null; // v => contents of a cell if (isTextTag(name)) { vIsOpen = false; // Process the value contents as required, now we have it all switch (nextDataType) { case BOOLEAN: char first = value.charAt(0); thisStr = first == '0' ? "FALSE" : "TRUE"; break; case ERROR: thisStr = "ERROR:" + value.toString(); break; case FORMULA: if (formulasNotResults) { thisStr = formula.toString(); } else { String fv = value.toString(); if (this.formatString != null) { try { // Try to use the value as a formattable number double d = Double.parseDouble(fv); thisStr = formatter.formatRawCellContents(d, this.formatIndex, this.formatString); } catch (NumberFormatException e) { // Formula is a String result not a Numeric one thisStr = fv; } } else { // No formating applied, just do raw value in all cases thisStr = fv; } } break; case INLINE_STRING: // TODO: Can these ever have formatting on them? XSSFRichTextString rtsi = new XSSFRichTextString(value.toString()); thisStr = rtsi.toString(); break; case SST_STRING: String sstIndex = value.toString(); try { int idx = Integer.parseInt(sstIndex); XSSFRichTextString rtss = new XSSFRichTextString(sharedStringsTable.getEntryAt(idx)); thisStr = rtss.toString(); } catch (NumberFormatException ex) { System.err.println("Failed to parse SST index '" + sstIndex + "': " + ex.toString()); } break; case NUMBER: String n = value.toString(); if (this.formatString != null) { if (this.formatString.equals("m/d/yy")) this.formatString = "yyyy-MM-dd"; thisStr = formatter.formatRawCellContents(Double.parseDouble(n), this.formatIndex, this.formatString); } else thisStr = n; break; default: thisStr = "(TODO: Unexpected type: " + nextDataType + ")"; break; } // Output output.cell(cellRef, thisStr); } else if ("f".equals(name)) { fIsOpen = false; } else if ("is".equals(name)) { isIsOpen = false; } else if ("row".equals(name)) { output.endRow(); } else if ("oddHeader".equals(name) || "evenHeader".equals(name) || "firstHeader".equals(name)) { hfIsOpen = false; output.headerFooter(headerFooter.toString(), true, name); } else if ("oddFooter".equals(name) || "evenFooter".equals(name) || "firstFooter".equals(name)) { hfIsOpen = false; output.headerFooter(headerFooter.toString(), false, name); } } /** * Captures characters only if a suitable element is open. * Originally was just "v"; extended for inlineStr also. */ public void characters(char[] ch, int start, int length) throws SAXException { if (vIsOpen) { value.append(ch, start, length); } if (fIsOpen) { formula.append(ch, start, length); } if (hfIsOpen) { headerFooter.append(ch, start, length); } } @Override public void endDocument() throws SAXException { this.output.end(); } /** * You need to implement this to handle the results * of the sheet parsing. */ public interface SheetContentsHandler { /** A row with the (zero based) row number has started */ public void startRow(int rowNum); /** A row with the (zero based) row number has ended */ public void endRow(); /** A cell, with the given formatted value, was encountered */ public void cell(String cellReference, String formattedValue); /** A header or footer has been encountered */ public void headerFooter(String text, boolean isHeader, String tagName); public void end(); } }