initial implementation of an Excel file LineReader class

pom.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -74,6 +75,13 @@
 			<version>1.16.10</version>
 			<scope>provided</scope>
 		</dependency>
+		<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
+		<dependency>
+			<groupId>org.apache.poi</groupId>
+			<artifactId>poi-ooxml</artifactId>
+			<version>3.15</version>
+		</dependency>
+
 	</dependencies>
 
 

src/main/java/edu/ucdenver/ccp/common/file/reader/ExcelFileLineReader.java

@@ -0,0 +1,82 @@
+package edu.ucdenver.ccp.common.file.reader;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.apache.poi.EncryptedDocumentException;
+import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Row.MissingCellPolicy;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.ss.usermodel.WorkbookFactory;
+
+import edu.ucdenver.ccp.common.file.reader.Line.LineTerminator;
+
+/**
+ * Simple class to read lines from an Excel file. This class assumes that the
+ * first line in a header (and uses the header to determine the number of
+ * columns in the file).
+ */
+public class ExcelFileLineReader extends LineReader<Line> {
+
+	private final int columnCount;
+	private final int rowCount;
+	private int currentRow = 1;
+	private final Workbook wb;
+	private final Sheet sheet;
+	private long byteOffset = -1;
+
+
+	public ExcelFileLineReader(File file, String skipLinePrefix) throws IOException {
+		this(new FileInputStream(file), skipLinePrefix);
+	}
+
+	public ExcelFileLineReader(InputStream inputStream, String skipLinePrefix) throws IOException {
+		super(skipLinePrefix);
+		try {
+			wb = WorkbookFactory.create(inputStream);
+		} catch (EncryptedDocumentException | InvalidFormatException e) {
+			throw new IOException(e);
+		}
+		sheet = wb.getSheetAt(0);
+
+		// use the header row to define the number of columns
+		Row headerRow = sheet.getRow(0);
+		columnCount = headerRow.getLastCellNum();
+		rowCount = sheet.getLastRowNum();
+
+	}
+
+	@Override
+	public void close() throws IOException {
+		wb.close();
+
+	}
+
+	@Override
+	protected Line getNextLine() throws IOException {
+		StringBuffer lineText = new StringBuffer();
+		String delimiter = "\t";
+		if (currentRow <= rowCount) {
+			Row r = sheet.getRow(currentRow++);
+			for (int col = 0; col < columnCount; col++) {
+				Cell cell = r.getCell(col, MissingCellPolicy.RETURN_BLANK_AS_NULL);
+				if (col > 0) {
+					lineText.append(delimiter);
+				}
+				if (cell != null) {
+					lineText.append(cell.getStringCellValue());
+				}
+			}
+			return new Line(lineText.toString(), LineTerminator.CR, getCharacterOffset(), getCodePointOffset(),
+					currentRow, byteOffset);
+		}
+		return null;
+	}
+
+}

src/test/java/edu/ucdenver/ccp/common/file/reader/ExcelFileLineReaderTest.java

@@ -0,0 +1,44 @@
+package edu.ucdenver.ccp.common.file.reader;
+
+import static org.junit.Assert.*;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.junit.Test;
+
+import edu.ucdenver.ccp.common.io.ClassPathUtil;
+
+public class ExcelFileLineReaderTest {
+
+	@Test
+	public void testReadXlsxFile() throws IOException {
+		InputStream xlsxStream = ClassPathUtil.getResourceStreamFromClasspath(getClass(), "sample.xlsx");
+		ExcelFileLineReader lineReader = new ExcelFileLineReader(xlsxStream, null);
+		Line line = lineReader.readLine();
+		assertEquals("a\tb\tc\td", line.getText());
+		line = lineReader.readLine();
+		assertEquals("a\t\tc\td", line.getText());
+		line = lineReader.readLine();
+		assertEquals("\tb\tc\td", line.getText());
+		line = lineReader.readLine();
+		assertEquals("\t\tc\t", line.getText());
+		lineReader.close();
+	}
+
+	@Test
+	public void testReadXlsFile() throws IOException {
+		InputStream xlsxStream = ClassPathUtil.getResourceStreamFromClasspath(getClass(), "sample.xls");
+		ExcelFileLineReader lineReader = new ExcelFileLineReader(xlsxStream, null);
+		Line line = lineReader.readLine();
+		assertEquals("a\tb\tc\td", line.getText());
+		line = lineReader.readLine();
+		assertEquals("a\t\tc\td", line.getText());
+		line = lineReader.readLine();
+		assertEquals("\tb\tc\td", line.getText());
+		line = lineReader.readLine();
+		assertEquals("\t\tc\t", line.getText());
+		lineReader.close();
+	}
+
+}