WIP: Excel extension

gsrs-core-entities/src/main/java/ix/ginas/exporters/ExcelSpreadsheet.java

@@ -1,18 +1,23 @@
 package ix.ginas.exporters;
 
-import gov.nih.ncats.common.io.IOUtil;
-import org.apache.poi.ss.usermodel.Cell;
-import org.apache.poi.ss.usermodel.Sheet;
-import org.apache.poi.ss.usermodel.Workbook;
-import org.apache.poi.xssf.streaming.SXSSFWorkbook;
-import org.apache.poi.xssf.usermodel.XSSFWorkbook;
-
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Date;
+import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
+
+import gov.nih.ncats.common.stream.StreamUtil;
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.streaming.SXSSFWorkbook;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+import gov.nih.ncats.common.io.IOUtil;
 
 /**
  * {@link Spreadsheet} implementation that writes out
@@ -28,6 +33,11 @@ public class ExcelSpreadsheet implements Spreadsheet {
 
     private final Sheet sheet;
 
+    private final boolean AUTO_SPILL_OVER=true;
+    private final long SPILL_OVER_AFTER=1000000;
+    private final boolean AUTO_SPILL_HEADER_REPEAT=true;
+
+    private List<String> headers;
 
     private final OutputStream out;
 
@@ -36,14 +46,47 @@ private ExcelSpreadsheet(Workbook workbook, OutputStream out) {
         this.out = out;
         //just first sheet
         sheet = workbook.createSheet();
+
     }
 
-
     @Override
     public SpreadsheetRow getRow(int i) {
         org.apache.poi.ss.usermodel.Row r = sheet.getRow(i);
+        int sheetIndex = 0;
+        int newRowIndex= i;
+        if(AUTO_SPILL_OVER) {
+            sheetIndex= (int) (i/SPILL_OVER_AFTER);
+            newRowIndex = (int) (i%SPILL_OVER_AFTER);
+
+            sheetIndex= (int) (i/SPILL_OVER_AFTER);
+            newRowIndex = (int) (i%SPILL_OVER_AFTER);
+            if(sheetIndex>0) {
+                if(AUTO_SPILL_HEADER_REPEAT) {
+                    newRowIndex++; //add a row for header
+                }
+            }
+
+            while(workbook.getNumberOfSheets()<sheetIndex+1) {
+                Sheet sheetnew= workbook.createSheet();
+                if(AUTO_SPILL_HEADER_REPEAT) {
+                    if(headers!=null) {
+                        Row rheaderNew = sheetnew.createRow(0);
+                        for(int c=0;c<headers.size();c++) {
+                            Cell cellNew=rheaderNew.createCell(c);
+                            cellNew.setCellValue(headers.get(c));
+                        }
+                    }
+                }
+            }
+        }
+        if(sheetIndex==0 && newRowIndex==1) { //second row
+            headers= StreamUtil.forIterable(workbook.getSheetAt(0).getRow(0))
+                    .map(c->c.getStringCellValue())
+                    .collect(Collectors.toList());
+        }
+
         if (r == null) {
-            r = sheet.createRow(i);
+            r = workbook.getSheetAt(sheetIndex).createRow(newRowIndex);
         }
         return new RowWrapper(r);
     }