# Refactoring & Improvement

src/main/java/com/github/pjfanning/xlsx/XmlUtils.java

@@ -13,7 +13,7 @@
 import java.io.InputStream;
 import java.util.*;
 
-public class XmlUtils {
+public final class XmlUtils {
 
   private static final NamespaceContext transitionalFormatNamespaceContext =
           new NamespaceContextImpl("ss", "http://schemas.openxmlformats.org/spreadsheetml/2006/main");
@@ -48,7 +48,7 @@ public static boolean evaluateBoolean(String bool) {
     return bool.equals(TRUE_AS_STRING) || bool.equalsIgnoreCase("true");
   }
 
-  private static class NamespaceContextImpl implements NamespaceContext {
+  private static final class NamespaceContextImpl implements NamespaceContext {
     private final Map<String, String> urisByPrefix = new HashMap<>();
 
     private final Map<String, Set<String>> prefixesByURI = new HashMap<>();

src/main/java/com/github/pjfanning/xlsx/impl/DateTimeUtil.java

@@ -5,7 +5,7 @@
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 
-class DateTimeUtil {
+final class DateTimeUtil {
 
   private DateTimeUtil() {}
 

src/main/java/com/github/pjfanning/xlsx/impl/LazySupplier.java

@@ -1,18 +1,18 @@
 package com.github.pjfanning.xlsx.impl;
 
-final class LazySupplier<T> implements Supplier {
-  private T content;
-  private final java.util.function.Supplier<T> functionalSupplier;
+final class LazySupplier<O> implements Supplier {
+	private O content;
+	private final java.util.function.Supplier<O> functionalSupplier;
 
-  LazySupplier(java.util.function.Supplier<T> functionalSupplier) {
-    this.functionalSupplier = functionalSupplier;
-  }
+	LazySupplier(java.util.function.Supplier<O> functionalSupplier) {
+		this.functionalSupplier = functionalSupplier;
+	}
 
-  @Override
-  public Object getContent() {
-    if (content == null) {
-      content = functionalSupplier.get();
-    }
-    return content;
-  }
-}
+	@Override
+	public Object getContent() {
+		if (content == null) {
+			content = functionalSupplier.get();
+		}
+		return content;
+	}
+}

src/main/java/com/github/pjfanning/xlsx/impl/StreamingCell.java

@@ -2,18 +2,22 @@
 
 import com.github.pjfanning.xlsx.XmlUtils;
 import com.github.pjfanning.xlsx.exceptions.NotSupportedException;
-import org.apache.poi.ss.formula.FormulaParseException;
-import org.apache.poi.ss.usermodel.*;
+import com.github.pjfanning.xlsx.impl.adapter.CellAdapter;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.CellStyle;
+import org.apache.poi.ss.usermodel.DateUtil;
+import org.apache.poi.ss.usermodel.Comment;
+import org.apache.poi.ss.usermodel.Hyperlink;
+import org.apache.poi.ss.usermodel.FormulaError;
 import org.apache.poi.ss.util.CellAddress;
-import org.apache.poi.ss.util.CellRangeAddress;
 import org.apache.poi.xssf.usermodel.XSSFRichTextString;
 
-import java.time.LocalDate;
 import java.time.LocalDateTime;
-import java.util.Calendar;
 import java.util.Date;
 
-public class StreamingCell implements Cell {
+public class StreamingCell implements CellAdapter {
 
   private static final Supplier NULL_SUPPLIER = () -> null;
 
@@ -395,167 +399,7 @@ public Comment getCellComment() {
   public Hyperlink getHyperlink() {
     return (sheet == null) ? null : sheet.getHyperlink(getAddress());
   }
-
-  /* Not supported */
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellType(CellType cellType) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setBlank() { throw new NotSupportedException("update operations are not supported"); }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(double value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(Date value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(Calendar value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(LocalDate value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(LocalDateTime value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(RichTextString value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(String value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellFormula(String formula) throws FormulaParseException {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void removeFormula() throws IllegalStateException {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellValue(boolean value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellErrorValue(byte value) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setAsActiveCell() {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setCellComment(Comment comment) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void removeCellComment() {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setHyperlink(Hyperlink link) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void removeHyperlink() {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Not supported
-   */
-  @Override
-  public CellRangeAddress getArrayFormulaRange() {
-    throw new NotSupportedException();
-  }
-
-  /**
-   * Not supported
-   */
-  @Override
-  public boolean isPartOfArrayFormulaGroup() {
-    throw new NotSupportedException();
-  }
-
+
   private static CellType getCellTypeFromShortHandType(final String cellType) {
     switch (cellType) {
       case "n":

src/main/java/com/github/pjfanning/xlsx/impl/StreamingRow.java

@@ -1,23 +1,30 @@
 package com.github.pjfanning.xlsx.impl;
 
-import com.github.pjfanning.xlsx.exceptions.NotSupportedException;
-import org.apache.poi.ss.usermodel.*;
-
-import java.util.*;
-
-public class StreamingRow implements Row {
+import com.github.pjfanning.xlsx.impl.adapter.RowAdapter;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellStyle;
+import org.apache.poi.ss.usermodel.CellType;
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.Iterator;
+import java.util.Spliterator;
+import java.util.Spliterators;
+
+public class StreamingRow implements RowAdapter {
   private final Sheet sheet;
   private final int rowIndex;
   private final boolean isHidden;
   private float height = -1.0f;
-  private TreeMap<Integer, Cell> cellMap = new TreeMap<>();
+  private final TreeMap<Integer, Cell> cellMap;
   private StreamingSheetReader streamingSheetReader;
   private CellStyle rowStyle;
 
   public StreamingRow(Sheet sheet, int rowIndex, boolean isHidden) {
     this.sheet = sheet;
     this.rowIndex = rowIndex;
     this.isHidden = isHidden;
+    cellMap = new TreeMap<>();
   }
 
   void setStreamingSheetReader(StreamingSheetReader streamingSheetReader) {
@@ -168,87 +175,4 @@ public void setRowStyle(CellStyle style) {
     this.rowStyle = style;
   }
 
-
-  /* Not supported */
-
-  /**
-   * Not supported
-   */
-  @Override
-  public Cell createCell(int column) {
-    throw new NotSupportedException();
-  }
-
-  /**
-   * Not supported
-   */
-  @Override
-  public Cell createCell(int i, CellType cellType) {
-    throw new NotSupportedException();
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void removeCell(Cell cell) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setRowNum(int rowNum) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setHeight(short height) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setZeroHeight(boolean zHeight) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void setHeightInPoints(float height) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Not supported
-   */
-  @Override
-  public int getOutlineLevel() {
-    throw new NotSupportedException();
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void shiftCellsRight(int firstShiftColumnIndex, int lastShiftColumnIndex, int step) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
-  /**
-   * Update operations are not supported
-   */
-  @Override
-  public void shiftCellsLeft(int firstShiftColumnIndex, int lastShiftColumnIndex, int step) {
-    throw new NotSupportedException("update operations are not supported");
-  }
-
 }