library(knitr)
library(xlsx)
## Loading required package: rJava
## Loading required package: xlsxjars
file <- system.file("tests", "test_import.xlsx", 
                    package = "xlsx")

From an Excel sheet to a data frame

Simple function read.xlsx()

sheet <- read.xlsx(file, 2)
kable(sheet)
Date Month Integer Boolean Double Datetime
2009-01-01 Jan 1 TRUE -1.123000e+00 2009-01-01 01:01:01
2009-02-01 Feb 2 FALSE 1.123000e+00 2009-02-01 02:02:01
2009-03-01 Mar 3 TRUE 3.162278e+01 2009-03-01 03:03:02
2009-04-01 Apr 4 FALSE 1.414214e+00 2009-04-01 04:04:03
2009-05-01 May 5 TRUE 3.010300e-01 2009-05-01 05:05:04
2009-06-01 Jun 6 FALSE 1.000000e+210 2009-06-01 06:06:05
2009-07-01 Jul 7 TRUE 0.000000e+00 2009-07-01 07:07:06
2009-08-01 Aug 8 FALSE 0.000000e+00 2009-08-01 08:08:07
2009-09-01 Sep 9 TRUE -1.230000e-01 2009-09-01 09:09:08
2009-10-01 Oct 10 FALSE 8.770000e-01 2009-10-01 10:10:09
2009-11-01 Nov 11 TRUE 1.877000e+00 2009-11-01 11:11:10
2009-12-01 Dec 12 FALSE 2.877000e+00 2009-12-01 12:12:11

Lower level, with access to workbook and sheet objects

wb <- loadWorkbook(file)  
sheets <- getSheets(wb)
sheet  <- sheets[[2]]  # extract the second sheet

List of java methods available

# see all the available java methods that you can call
.jmethods(sheet)
##   [1] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setForceFormulaRecalculation(boolean)"                                                                          
##   [2] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getForceFormulaRecalculation()"                                                                              
##   [3] "public org.apache.poi.ss.usermodel.Drawing org.apache.poi.xssf.usermodel.XSSFSheet.createDrawingPatriarch()"                                                        
##   [4] "public org.apache.poi.xssf.usermodel.XSSFDrawing org.apache.poi.xssf.usermodel.XSSFSheet.createDrawingPatriarch()"                                                  
##   [5] "public void org.apache.poi.xssf.usermodel.XSSFSheet.ungroupRow(int,int)"                                                                                            
##   [6] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isSelected()"                                                                                                
##   [7] "public static void org.apache.poi.xssf.usermodel.XSSFSheet.setCellComment(java.lang.String,org.apache.poi.xssf.usermodel.XSSFComment)"                              
##   [8] "public void org.apache.poi.xssf.usermodel.XSSFSheet.addHyperlink(org.apache.poi.xssf.usermodel.XSSFHyperlink)"                                                      
##   [9] "public java.lang.String org.apache.poi.xssf.usermodel.XSSFSheet.getActiveCell()"                                                                                    
##  [10] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setActiveCell(java.lang.String)"                                                                                
##  [11] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.hasComments()"                                                                                               
##  [12] "public org.apache.poi.xssf.usermodel.XSSFRow org.apache.poi.xssf.usermodel.XSSFSheet.getRow(int)"                                                                   
##  [13] "public org.apache.poi.ss.usermodel.Row org.apache.poi.xssf.usermodel.XSSFSheet.getRow(int)"                                                                         
##  [14] "public int[] org.apache.poi.xssf.usermodel.XSSFSheet.getRowBreaks()"                                                                                                
##  [15] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getRowSumsBelow()"                                                                                           
##  [16] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setRowSumsBelow(boolean)"                                                                                       
##  [17] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getRowSumsRight()"                                                                                           
##  [18] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setRowSumsRight(boolean)"                                                                                       
##  [19] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getScenarioProtect()"                                                                                        
##  [20] "public short org.apache.poi.xssf.usermodel.XSSFSheet.getTopRow()"                                                                                                   
##  [21] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getVerticallyCenter()"                                                                                       
##  [22] "public void org.apache.poi.xssf.usermodel.XSSFSheet.groupColumn(int,int)"                                                                                           
##  [23] "public void org.apache.poi.xssf.usermodel.XSSFSheet.groupRow(int,int)"                                                                                              
##  [24] "public org.apache.poi.xssf.usermodel.XSSFComment org.apache.poi.xssf.usermodel.XSSFSheet.createComment()"                                                           
##  [25] "public org.apache.poi.ss.usermodel.Row org.apache.poi.xssf.usermodel.XSSFSheet.createRow(int)"                                                                      
##  [26] "public org.apache.poi.xssf.usermodel.XSSFRow org.apache.poi.xssf.usermodel.XSSFSheet.createRow(int)"                                                                
##  [27] "public void org.apache.poi.xssf.usermodel.XSSFSheet.createSplitPane(int,int,int,int,int)"                                                                           
##  [28] "public org.apache.poi.ss.usermodel.Comment org.apache.poi.xssf.usermodel.XSSFSheet.getCellComment(int,int)"                                                         
##  [29] "public org.apache.poi.xssf.usermodel.XSSFComment org.apache.poi.xssf.usermodel.XSSFSheet.getCellComment(int,int)"                                                   
##  [30] "public org.apache.poi.xssf.usermodel.XSSFHyperlink org.apache.poi.xssf.usermodel.XSSFSheet.getHyperlink(int,int)"                                                   
##  [31] "public int[] org.apache.poi.xssf.usermodel.XSSFSheet.getColumnBreaks()"                                                                                             
##  [32] "public org.openxmlformats.schemas.spreadsheetml.x2006.main.CTWorksheet org.apache.poi.xssf.usermodel.XSSFSheet.getCTWorksheet()"                                    
##  [33] "public java.lang.String org.apache.poi.xssf.usermodel.XSSFSheet.getSheetName()"                                                                                     
##  [34] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setFitToPage(boolean)"                                                                                          
##  [35] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setHorizontallyCenter(boolean)"                                                                                 
##  [36] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setVerticallyCenter(boolean)"                                                                                   
##  [37] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setRowGroupCollapsed(int,boolean)"                                                                              
##  [38] "public int org.apache.poi.xssf.usermodel.XSSFSheet.findEndOfRowOutlineGroup(int)"                                                                                   
##  [39] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setZoom(int)"                                                                                                   
##  [40] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setZoom(int,int)"                                                                                               
##  [41] "public void org.apache.poi.xssf.usermodel.XSSFSheet.shiftRows(int,int,int,boolean,boolean)"                                                                         
##  [42] "public void org.apache.poi.xssf.usermodel.XSSFSheet.shiftRows(int,int,int)"                                                                                         
##  [43] "public void org.apache.poi.xssf.usermodel.XSSFSheet.showInPane(int,int)"                                                                                            
##  [44] "public void org.apache.poi.xssf.usermodel.XSSFSheet.showInPane(short,short)"                                                                                        
##  [45] "public void org.apache.poi.xssf.usermodel.XSSFSheet.ungroupColumn(int,int)"                                                                                         
##  [46] "public int org.apache.poi.xssf.usermodel.XSSFSheet.addMergedRegion(org.apache.poi.ss.util.CellRangeAddress)"                                                        
##  [47] "public void org.apache.poi.xssf.usermodel.XSSFSheet.autoSizeColumn(int)"                                                                                            
##  [48] "public void org.apache.poi.xssf.usermodel.XSSFSheet.autoSizeColumn(int,boolean)"                                                                                    
##  [49] "public void org.apache.poi.xssf.usermodel.XSSFSheet.createFreezePane(int,int)"                                                                                      
##  [50] "public void org.apache.poi.xssf.usermodel.XSSFSheet.createFreezePane(int,int,int,int)"                                                                              
##  [51] "public org.openxmlformats.schemas.spreadsheetml.x2006.main.CTCellFormula org.apache.poi.xssf.usermodel.XSSFSheet.getSharedFormula(int)"                             
##  [52] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isAutoFilterLocked()"                                                                                        
##  [53] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isDeleteColumnsLocked()"                                                                                     
##  [54] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isDeleteRowsLocked()"                                                                                        
##  [55] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isFormatCellsLocked()"                                                                                       
##  [56] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isFormatColumnsLocked()"                                                                                     
##  [57] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isFormatRowsLocked()"                                                                                        
##  [58] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isInsertColumnsLocked()"                                                                                     
##  [59] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isInsertHyperlinksLocked()"                                                                                  
##  [60] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isInsertRowsLocked()"                                                                                        
##  [61] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isPivotTablesLocked()"                                                                                       
##  [62] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isSortLocked()"                                                                                              
##  [63] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isObjectsLocked()"                                                                                           
##  [64] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isScenariosLocked()"                                                                                         
##  [65] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isSelectLockedCellsLocked()"                                                                                 
##  [66] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isSelectUnlockedCellsLocked()"                                                                               
##  [67] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isSheetLocked()"                                                                                             
##  [68] "public void org.apache.poi.xssf.usermodel.XSSFSheet.enableLocking()"                                                                                                
##  [69] "public void org.apache.poi.xssf.usermodel.XSSFSheet.disableLocking()"                                                                                               
##  [70] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockAutoFilter()"                                                                                               
##  [71] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockDeleteColumns()"                                                                                            
##  [72] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockDeleteRows()"                                                                                               
##  [73] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockFormatCells()"                                                                                              
##  [74] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockFormatColumns()"                                                                                            
##  [75] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setColumnHidden(int,boolean)"                                                                                   
##  [76] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setColumnWidth(int,int)"                                                                                        
##  [77] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDefaultColumnStyle(int,org.apache.poi.ss.usermodel.CellStyle)"                                               
##  [78] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDefaultColumnWidth(int)"                                                                                     
##  [79] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDefaultRowHeight(short)"                                                                                     
##  [80] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDefaultRowHeightInPoints(float)"                                                                             
##  [81] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDisplayFormulas(boolean)"                                                                                    
##  [82] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setRepeatingRows(org.apache.poi.ss.util.CellRangeAddress)"                                                      
##  [83] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setRepeatingColumns(org.apache.poi.ss.util.CellRangeAddress)"                                                   
##  [84] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setSelected(boolean)"                                                                                           
##  [85] "public org.apache.poi.ss.usermodel.CellRange org.apache.poi.xssf.usermodel.XSSFSheet.removeArrayFormula(org.apache.poi.ss.usermodel.Cell)"                          
##  [86] "public org.apache.poi.ss.usermodel.DataValidationHelper org.apache.poi.xssf.usermodel.XSSFSheet.getDataValidationHelper()"                                          
##  [87] "public java.util.List org.apache.poi.xssf.usermodel.XSSFSheet.getDataValidations()"                                                                                 
##  [88] "public void org.apache.poi.xssf.usermodel.XSSFSheet.addValidationData(org.apache.poi.ss.usermodel.DataValidation)"                                                  
##  [89] "public int org.apache.poi.xssf.usermodel.XSSFSheet.getColumnWidth(int)"                                                                                             
##  [90] "public int org.apache.poi.xssf.usermodel.XSSFSheet.getDefaultColumnWidth()"                                                                                         
##  [91] "public short org.apache.poi.xssf.usermodel.XSSFSheet.getDefaultRowHeight()"                                                                                         
##  [92] "public float org.apache.poi.xssf.usermodel.XSSFSheet.getDefaultRowHeightInPoints()"                                                                                 
##  [93] "public org.apache.poi.ss.usermodel.CellStyle org.apache.poi.xssf.usermodel.XSSFSheet.getColumnStyle(int)"                                                           
##  [94] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setRightToLeft(boolean)"                                                                                        
##  [95] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isRightToLeft()"                                                                                             
##  [96] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getDisplayGuts()"                                                                                            
##  [97] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDisplayGuts(boolean)"                                                                                        
##  [98] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isDisplayZeros()"                                                                                            
##  [99] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDisplayZeros(boolean)"                                                                                       
## [100] "public int org.apache.poi.xssf.usermodel.XSSFSheet.getFirstRowNum()"                                                                                                
## [101] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getFitToPage()"                                                                                              
## [102] "public org.apache.poi.ss.usermodel.Footer org.apache.poi.xssf.usermodel.XSSFSheet.getFooter()"                                                                      
## [103] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setAutobreaks(boolean)"                                                                                         
## [104] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setColumnBreak(int)"                                                                                            
## [105] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setColumnGroupCollapsed(int,boolean)"                                                                           
## [106] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isColumnBroken(int)"                                                                                         
## [107] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isColumnHidden(int)"                                                                                         
## [108] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isDisplayFormulas()"                                                                                         
## [109] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isDisplayGridlines()"                                                                                        
## [110] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDisplayGridlines(boolean)"                                                                                   
## [111] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isDisplayRowColHeadings()"                                                                                   
## [112] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setDisplayRowColHeadings(boolean)"                                                                              
## [113] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isPrintGridlines()"                                                                                          
## [114] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setPrintGridlines(boolean)"                                                                                     
## [115] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.isRowBroken(int)"                                                                                            
## [116] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setRowBreak(int)"                                                                                               
## [117] "public void org.apache.poi.xssf.usermodel.XSSFSheet.removeColumnBreak(int)"                                                                                         
## [118] "public void org.apache.poi.xssf.usermodel.XSSFSheet.removeMergedRegion(int)"                                                                                        
## [119] "public void org.apache.poi.xssf.usermodel.XSSFSheet.removeRow(org.apache.poi.ss.usermodel.Row)"                                                                     
## [120] "public void org.apache.poi.xssf.usermodel.XSSFSheet.removeRowBreak(int)"                                                                                            
## [121] "public java.util.Iterator org.apache.poi.xssf.usermodel.XSSFSheet.rowIterator()"                                                                                    
## [122] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getAutobreaks()"                                                                                             
## [123] "public org.apache.poi.xssf.usermodel.helpers.ColumnHelper org.apache.poi.xssf.usermodel.XSSFSheet.getColumnHelper()"                                                
## [124] "public org.apache.poi.xssf.usermodel.XSSFWorkbook org.apache.poi.xssf.usermodel.XSSFSheet.getWorkbook()"                                                            
## [125] "public org.apache.poi.ss.usermodel.Workbook org.apache.poi.xssf.usermodel.XSSFSheet.getWorkbook()"                                                                  
## [126] "public org.apache.poi.xssf.usermodel.XSSFAutoFilter org.apache.poi.xssf.usermodel.XSSFSheet.setAutoFilter(org.apache.poi.ss.util.CellRangeAddress)"                 
## [127] "public org.apache.poi.ss.usermodel.AutoFilter org.apache.poi.xssf.usermodel.XSSFSheet.setAutoFilter(org.apache.poi.ss.util.CellRangeAddress)"                       
## [128] "public org.apache.poi.xssf.usermodel.XSSFTable org.apache.poi.xssf.usermodel.XSSFSheet.createTable()"                                                               
## [129] "public java.util.List org.apache.poi.xssf.usermodel.XSSFSheet.getTables()"                                                                                          
## [130] "public org.apache.poi.ss.usermodel.SheetConditionalFormatting org.apache.poi.xssf.usermodel.XSSFSheet.getSheetConditionalFormatting()"                              
## [131] "public org.apache.poi.xssf.usermodel.XSSFSheetConditionalFormatting org.apache.poi.xssf.usermodel.XSSFSheet.getSheetConditionalFormatting()"                        
## [132] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setTabColor(int)"                                                                                               
## [133] "public org.apache.poi.ss.util.CellRangeAddress org.apache.poi.xssf.usermodel.XSSFSheet.getRepeatingRows()"                                                          
## [134] "public org.apache.poi.ss.util.CellRangeAddress org.apache.poi.xssf.usermodel.XSSFSheet.getRepeatingColumns()"                                                       
## [135] "public org.apache.poi.ss.usermodel.Header org.apache.poi.xssf.usermodel.XSSFSheet.getHeader()"                                                                      
## [136] "public org.apache.poi.ss.usermodel.Footer org.apache.poi.xssf.usermodel.XSSFSheet.getOddFooter()"                                                                   
## [137] "public org.apache.poi.ss.usermodel.Footer org.apache.poi.xssf.usermodel.XSSFSheet.getEvenFooter()"                                                                  
## [138] "public org.apache.poi.ss.usermodel.Footer org.apache.poi.xssf.usermodel.XSSFSheet.getFirstFooter()"                                                                 
## [139] "public org.apache.poi.ss.usermodel.Header org.apache.poi.xssf.usermodel.XSSFSheet.getOddHeader()"                                                                   
## [140] "public org.apache.poi.ss.usermodel.Header org.apache.poi.xssf.usermodel.XSSFSheet.getEvenHeader()"                                                                  
## [141] "public org.apache.poi.ss.usermodel.Header org.apache.poi.xssf.usermodel.XSSFSheet.getFirstHeader()"                                                                 
## [142] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getHorizontallyCenter()"                                                                                     
## [143] "public int org.apache.poi.xssf.usermodel.XSSFSheet.getLastRowNum()"                                                                                                 
## [144] "public short org.apache.poi.xssf.usermodel.XSSFSheet.getLeftCol()"                                                                                                  
## [145] "public double org.apache.poi.xssf.usermodel.XSSFSheet.getMargin(short)"                                                                                             
## [146] "public void org.apache.poi.xssf.usermodel.XSSFSheet.setMargin(short,double)"                                                                                        
## [147] "public org.apache.poi.ss.util.CellRangeAddress org.apache.poi.xssf.usermodel.XSSFSheet.getMergedRegion(int)"                                                        
## [148] "public int org.apache.poi.xssf.usermodel.XSSFSheet.getNumMergedRegions()"                                                                                           
## [149] "public int org.apache.poi.xssf.usermodel.XSSFSheet.getNumHyperlinks()"                                                                                              
## [150] "public org.apache.poi.hssf.util.PaneInformation org.apache.poi.xssf.usermodel.XSSFSheet.getPaneInformation()"                                                       
## [151] "public int org.apache.poi.xssf.usermodel.XSSFSheet.getPhysicalNumberOfRows()"                                                                                       
## [152] "public org.apache.poi.ss.usermodel.PrintSetup org.apache.poi.xssf.usermodel.XSSFSheet.getPrintSetup()"                                                              
## [153] "public org.apache.poi.xssf.usermodel.XSSFPrintSetup org.apache.poi.xssf.usermodel.XSSFSheet.getPrintSetup()"                                                        
## [154] "public boolean org.apache.poi.xssf.usermodel.XSSFSheet.getProtect()"                                                                                                
## [155] "public void org.apache.poi.xssf.usermodel.XSSFSheet.protectSheet(java.lang.String)"                                                                                 
## [156] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockFormatRows()"                                                                                               
## [157] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockInsertColumns()"                                                                                            
## [158] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockInsertHyperlinks()"                                                                                         
## [159] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockInsertRows()"                                                                                               
## [160] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockPivotTables()"                                                                                              
## [161] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockSort()"                                                                                                     
## [162] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockObjects()"                                                                                                  
## [163] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockScenarios()"                                                                                                
## [164] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockSelectLockedCells()"                                                                                        
## [165] "public void org.apache.poi.xssf.usermodel.XSSFSheet.lockSelectUnlockedCells()"                                                                                      
## [166] "public org.apache.poi.ss.usermodel.CellRange org.apache.poi.xssf.usermodel.XSSFSheet.setArrayFormula(java.lang.String,org.apache.poi.ss.util.CellRangeAddress)"     
## [167] "public java.util.Iterator org.apache.poi.xssf.usermodel.XSSFSheet.iterator()"                                                                                       
## [168] "public final org.apache.poi.openxml4j.opc.PackagePart org.apache.poi.POIXMLDocumentPart.getPackagePart()"                                                           
## [169] "public final void org.apache.poi.POIXMLDocumentPart.addRelation(java.lang.String,org.apache.poi.POIXMLDocumentPart)"                                                
## [170] "public final org.apache.poi.POIXMLDocumentPart org.apache.poi.POIXMLDocumentPart.getRelationById(java.lang.String)"                                                 
## [171] "public final java.lang.String org.apache.poi.POIXMLDocumentPart.getRelationId(org.apache.poi.POIXMLDocumentPart)"                                                   
## [172] "public final java.util.List org.apache.poi.POIXMLDocumentPart.getRelations()"                                                                                       
## [173] "public final org.apache.poi.openxml4j.opc.PackageRelationship org.apache.poi.POIXMLDocumentPart.getPackageRelationship()"                                           
## [174] "public final org.apache.poi.POIXMLDocumentPart org.apache.poi.POIXMLDocumentPart.createRelationship(org.apache.poi.POIXMLRelation,org.apache.poi.POIXMLFactory)"    
## [175] "public final org.apache.poi.POIXMLDocumentPart org.apache.poi.POIXMLDocumentPart.createRelationship(org.apache.poi.POIXMLRelation,org.apache.poi.POIXMLFactory,int)"
## [176] "public java.lang.String org.apache.poi.POIXMLDocumentPart.toString()"                                                                                               
## [177] "public final org.apache.poi.POIXMLDocumentPart org.apache.poi.POIXMLDocumentPart.getParent()"                                                                       
## [178] "public final void java.lang.Object.wait(long,int) throws java.lang.InterruptedException"                                                                            
## [179] "public final native void java.lang.Object.wait(long) throws java.lang.InterruptedException"                                                                         
## [180] "public final void java.lang.Object.wait() throws java.lang.InterruptedException"                                                                                    
## [181] "public boolean java.lang.Object.equals(java.lang.Object)"                                                                                                           
## [182] "public native int java.lang.Object.hashCode()"                                                                                                                      
## [183] "public final native java.lang.Class java.lang.Object.getClass()"                                                                                                    
## [184] "public final native void java.lang.Object.notify()"                                                                                                                 
## [185] "public final native void java.lang.Object.notifyAll()"
# for example
sheet$getLastRowNum()
## [1] 12