From 42643fe79b838923643f3fa6b806c289007ef7f4 Mon Sep 17 00:00:00 2001
From: "Edward M. Kagan" <pagan@tabor.one>
Date: Thu, 4 Nov 2021 05:22:02 +0300
Subject: [PATCH] csv merger added

---
 csv-merger/pom.xml                            | 18 ++++
 .../tech/jaxrsbench/csv/merger/Merger.java    | 82 +++++++++++++++++++
 2 files changed, 100 insertions(+)
 create mode 100644 csv-merger/pom.xml
 create mode 100644 csv-merger/src/main/java/twopm/tech/jaxrsbench/csv/merger/Merger.java

diff --git a/csv-merger/pom.xml b/csv-merger/pom.xml
new file mode 100644
index 0000000..50ef822
--- /dev/null
+++ b/csv-merger/pom.xml
@@ -0,0 +1,18 @@
+<?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/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>twopm.tech.jax-rs-bench</groupId>
+        <artifactId>bom</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <artifactId>csv-merger</artifactId>
+    <packaging>jar</packaging>
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-csv</artifactId>
+            <version>1.9.0</version>
+        </dependency>
+    </dependencies>
+</project>
\ No newline at end of file
diff --git a/csv-merger/src/main/java/twopm/tech/jaxrsbench/csv/merger/Merger.java b/csv-merger/src/main/java/twopm/tech/jaxrsbench/csv/merger/Merger.java
new file mode 100644
index 0000000..a5d7b35
--- /dev/null
+++ b/csv-merger/src/main/java/twopm/tech/jaxrsbench/csv/merger/Merger.java
@@ -0,0 +1,82 @@
+package twopm.tech.jaxrsbench.csv.merger;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.FilenameFilter;
+import java.io.IOException;
+import java.io.Reader;
+import static java.lang.System.in;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import org.apache.commons.csv.CSVFormat;
+import org.apache.commons.csv.CSVPrinter;
+import org.apache.commons.csv.CSVRecord;
+
+/**
+ *
+ * @author Edward M. Kagan {@literal <}kaganem{@literal @}2pm.tech{@literal >}
+ */
+public class Merger {
+
+	public static final void main(String[] args) throws FileNotFoundException, IOException {
+		if (args.length != 1) {
+			System.err.println("I need exactly one argument!");
+			System.exit(-1);
+		}
+		File dataDir = new File(args[0]);
+		if (!dataDir.exists()) {
+			System.err.println("Directory '" + dataDir.getPath() + "' does not exist!");
+			System.exit(-2);
+		}
+		
+		File[] files = dataDir.listFiles(new FilenameFilter() {
+			@Override
+			public boolean accept(File file, String name) {
+				return  new File(file, name).isFile() && name.endsWith(".csv");
+			}
+		});
+		
+		BufferedWriter writer = new BufferedWriter(new FileWriter(new File(dataDir, "merged.csv")));
+		CSVPrinter csvPrinter = null;
+		boolean headerRow;
+		
+		for (File file : files) {
+			Reader in = new FileReader(file);
+			 
+			headerRow = true;
+			Iterable<CSVRecord> records = CSVFormat.RFC4180.parse(in);
+			for (CSVRecord record : records) {
+				if (headerRow) {
+					if (csvPrinter == null) {
+						String[] header = new String[4 + record.size()];
+						header[0]="action";
+						header[1]="version";
+						header[2]="module";
+						header[3]="jdk";
+						
+						for (int col = 0; col < record.size(); col++) {
+							header[4 + col] = record.get(col);
+						}
+						csvPrinter = new CSVPrinter(writer, CSVFormat.DEFAULT.withHeader(header));
+						System.out.println(csvPrinter);
+					}
+				} else {
+					String[] prefix = file.getName().replace(".csv", "").split("_");
+					String[] row = new String[4 + record.size()];
+					for (int col = 0; col < record.size(); col++) {
+						row[4 + col] = record.get(col);
+					}
+					System.arraycopy(prefix, 0, row, 0, prefix.length);
+					csvPrinter.printRecord(row);
+				}
+				if (headerRow) headerRow = !headerRow;
+			}
+		}
+		if (csvPrinter != null) {
+			csvPrinter.flush();
+		}
+	}
+}