[New] Added a CsvParser

src/main/java/ch/eitchnet/utils/csv/CsvParser.java

@@ -0,0 +1,154 @@
+/*
+ * Copyright 2015 Robert von Burg <eitch@eitchnet.ch>
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ch.eitchnet.utils.csv;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Scanner;
+
+import ch.eitchnet.utils.dbc.DBC;
+import ch.eitchnet.utils.xml.XmlKeyValue;
+
+/**
+ * @author Robert von Burg <eitch@eitchnet.ch>
+ */
+public class CsvParser {
+
+	private InputStream inputStream;
+
+	/**
+	 * @param inputStream
+	 */
+	public CsvParser(InputStream inputStream) {
+		DBC.PRE.assertNotNull("InputStream may not be null!", inputStream);
+		this.inputStream = inputStream;
+	}
+
+	public CsvData parseData() {
+
+		CsvData data = new CsvData();
+
+		int lineNr = 0;
+		boolean headerRead = false;
+
+		try {
+			try (BufferedReader reader = new BufferedReader(new InputStreamReader(this.inputStream))) {
+				String line;
+				while ((line = reader.readLine()) != null) {
+
+					line = line.trim();
+					if (line.isEmpty())
+						continue;
+					if (line.charAt(0) == '#')
+						continue;
+
+					try (Scanner scanner = new Scanner(line)) {
+						scanner.useDelimiter(";");
+						if (headerRead) {
+							int column = 0;
+							CsvRow row = new CsvRow(lineNr);
+							while (scanner.hasNext()) {
+								row.addColumnValue(data.getHeaderAtIndex(column), scanner.next());
+								column++;
+							}
+							data.addRow(row);
+						} else {
+							while (scanner.hasNext()) {
+								data.addHeader(scanner.next().trim());
+							}
+							headerRead = true;
+						}
+					}
+
+					lineNr++;
+				}
+			}
+		} catch (IOException e) {
+			throw new RuntimeException("Failed to read csv data at line " + lineNr + " due to " + e.getMessage(), e);
+		}
+
+		return data;
+	}
+
+	public class CsvData {
+		private List<String> headers;
+		private List<CsvRow> rows;
+
+		public CsvData() {
+			this.headers = new ArrayList<>();
+			this.rows = new ArrayList<>();
+		}
+
+		public String getHeaderAtIndex(int column) {
+			if (this.headers.size() < column + 1) {
+				throw new IllegalArgumentException("No header exists at column index " + column);
+			}
+			return this.headers.get(column);
+		}
+
+		public void addHeader(String header) {
+			this.headers.add(header);
+		}
+
+		public void addRow(CsvRow row) {
+			this.rows.add(row);
+		}
+
+		public List<String> getHeaders() {
+			return this.headers;
+		}
+
+		public List<CsvRow> getRows() {
+			return this.rows;
+		}
+	}
+
+	public class CsvRow {
+		private int index;
+		private List<XmlKeyValue> values;
+
+		public CsvRow(int index) {
+			this.index = index;
+			this.values = new ArrayList<>();
+		}
+
+		public int getIndex() {
+			return this.index;
+		}
+
+		public void addColumnValue(String header, String value) {
+			this.values.add(new XmlKeyValue(header, value));
+		}
+
+		public String getColumnValue(String header) {
+			for (Iterator<XmlKeyValue> iter = this.values.iterator(); iter.hasNext();) {
+				XmlKeyValue next = iter.next();
+				if (next.getKey().equals(header))
+					return next.getValue();
+			}
+			throw new IllegalArgumentException("No value exists for header" + header);
+		}
+
+		public List<XmlKeyValue> getValues() {
+			return this.values;
+		}
+	}
+}

src/test/java/ch/eitchnet/utils/csv/CsvParserTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2015 Robert von Burg <eitch@eitchnet.ch>
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ch.eitchnet.utils.csv;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.InputStream;
+import java.util.Arrays;
+
+import org.junit.Test;
+
+import ch.eitchnet.utils.csv.CsvParser.CsvData;
+import ch.eitchnet.utils.csv.CsvParser.CsvRow;
+
+/**
+ * @author Robert von Burg <eitch@eitchnet.ch>
+ */
+public class CsvParserTest {
+
+	@Test
+	public void shouldParseFile() {
+
+		InputStream inputStream = CsvParserTest.class.getResourceAsStream("/test_data.csv");
+
+		CsvParser csvParser = new CsvParser(inputStream);
+		CsvData csvData = csvParser.parseData();
+
+		assertEquals(3, csvData.getHeaders().size());
+		assertEquals(Arrays.asList("title", "description", "nrOfPages"), csvData.getHeaders());
+		assertEquals(3, csvData.getRows().size());
+
+		CsvRow row = csvData.getRows().get(0);
+		assertEquals("A", row.getColumnValue("title"));
+		assertEquals("a", row.getColumnValue("description"));
+		assertEquals("1", row.getColumnValue("nrOfPages"));
+
+		row = csvData.getRows().get(2);
+		assertEquals("C", row.getColumnValue("title"));
+		assertEquals("c", row.getColumnValue("description"));
+		assertEquals("3", row.getColumnValue("nrOfPages"));
+
+		assertEquals(3, row.getValues().size());
+	}
+}

src/test/resources/test_data.csv

@@ -0,0 +1,6 @@
+#Comment
+title;description;nrOfPages
+A;a;1
+# Another comment
+B;b;2
+C;c;3