Add CsvUtils

Author: Dokyeongyun

src/main/java/root/utils/CsvUtils.java

@@ -0,0 +1,83 @@
+package root.utils;
+
+import java.lang.reflect.Field;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.opencsv.CSVWriter;
+
+public class CsvUtils {
+
+	/**
+	 * 
+	 * @param list
+	 * @param clazz
+	 * @return
+	 */
+	public static String toCsvString(List<?> list, Class<?> clazz) {
+		StringBuffer sb = new StringBuffer();
+		
+		try {
+			Field[] fields = clazz.getDeclaredFields();
+			List<String> fieldName = Arrays.asList(fields).stream().map(f -> (f.getName()))
+					.collect(Collectors.toList());
+
+			sb.append(createCsvHeader(fieldName));
+
+			for (Object item : list) {
+				sb.append(CSVWriter.RFC4180_LINE_END).append(createCsvRow(item, clazz));
+			}
+		} catch (IllegalArgumentException | IllegalAccessException e) {
+			e.printStackTrace();
+		}
+
+		return sb.toString();
+	}
+
+	/**
+	 * 
+	 * @param fieldNames
+	 * @return
+	 */
+	public static String createCsvHeader(List<String> fieldNames) {
+		StringBuffer sb = new StringBuffer();
+
+		for (String f : fieldNames) {
+			sb.append(sb.isEmpty() ? f : CSVWriter.DEFAULT_SEPARATOR + f);
+		}
+
+		return sb.toString();
+	}
+	
+	/**
+	 * 
+	 * @param object
+	 * @param clazz
+	 * @return
+	 * @throws IllegalArgumentException
+	 * @throws IllegalAccessException
+	 */
+	public static String createCsvRow(Object object, Class<?> clazz)
+			throws IllegalArgumentException, IllegalAccessException {
+		StringBuffer sb = new StringBuffer();
+
+		if (StringUtils.equals(object.getClass().getName(), clazz.getName())) {
+			for (Field f : clazz.getDeclaredFields()) {
+				boolean accessible = f.canAccess(object);
+				f.setAccessible(true);
+
+				String appender = sb.isEmpty() ? StringUtils.getIfEmpty(f.get(object).toString(), () -> "-")
+						: CSVWriter.DEFAULT_SEPARATOR + StringUtils.getIfEmpty(f.get(object).toString(), () -> "-");
+				sb.append(appender);
+
+				f.setAccessible(accessible);
+			}
+		}
+
+		return sb.toString();
+	}
+
+}