Added the ability to export the stack to a file

mdbook/src/Chapters/OperationalCommands.md

@@ -8,6 +8,7 @@ Operational commands are commands that do not directly impact your stack numbers
 |-------|-------------|
 |debug|Toggle debug mode which will display additional information on what's happening internally in the program.  Same as the `-D` command line switch.  Probably not the useful for a normal user|
 |h <br> ?|`h` or `?` will display the in-program help page|
+|export `FILE`|`Export` will simply export the current stack values into the file specified. The format is very simple with one number per line. The output will be ordered as on the screen with the top of the stack item at the end of the file and the last stack item at the top. If the file exists, it will be overwritten.|
 |import `FILE`|With `import` RPNCalc will replace the current stack with one loaded from a file.  The file format is simple, just one number per line.  Do not include any comments or alphanumeric/special characters.  Just one number per line with the last number being `line1` - just like the display in RPNCalc|
 |list stacks|List the current saved stacks on the system, including the one currently in use|
 |list mem|Display the contents of the memory slots|

pom.xml

@@ -3,7 +3,7 @@
 
 	<groupId>org.fross</groupId>
 	<artifactId>rpncalc</artifactId>
-	<version>4.8.1</version>
+	<version>4.8.2</version>
 	<packaging>jar</packaging>
 
 	<name>rpncalc</name>

snap/snapcraft.yaml

@@ -1,5 +1,5 @@
 name: rpncalc
-version: '4.8.1'
+version: '4.8.2'
 summary: The command line Reverse Polish Notation (RPN) calculator
 description: |
   RPNCalc is an easy to use command line based Reverse Polish

src/main/java/org/fross/rpncalc/CommandParser.java

@@ -336,6 +336,11 @@ public static void Parse(StackObj calcStack, StackObj calcStack2, String cmdInpu
 			StackOperations.cmdLoad(calcStack, calcStack2, cmdInputParam);
 			break;
 
+		// Export the current stack to a provided file
+		case "export":
+			StackOperations.exportStackToDisk(calcStack, cmdInputParam);
+			break;
+
 		// Import stack from disk
 		case "import":
 			StackOperations.importStackFromDisk(calcStack, cmdInputParam);

src/main/java/org/fross/rpncalc/Help.java

@@ -139,6 +139,7 @@ public static void Display() {
 		Output.printColorln(Ansi.Color.YELLOW, "\nOperational Commands:");
 		Output.printColorln(Ansi.Color.WHITE, " debug             Toggle DEBUG mode on/off");
 		Output.printColorln(Ansi.Color.WHITE, " h|?               Show this help information.  Either key will work");
+		Output.printColorln(Ansi.Color.WHITE, " export FILE       Export the current stack to the provided file (one number per line)");
 		Output.printColorln(Ansi.Color.WHITE, " import FILE       Replace current stack with file contents (one number per line)");
 		Output.printColorln(Ansi.Color.WHITE, " list func         Display the detailed user defined functions");
 		Output.printColorln(Ansi.Color.WHITE, " list mem          Display contents of the memory slots");

src/main/java/org/fross/rpncalc/StackOperations.java

@@ -27,6 +27,7 @@
 package org.fross.rpncalc;
 
 import java.io.File;
+import java.io.FileWriter;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -185,6 +186,63 @@ public static void cmdSwapStack(StackObj calcStack, StackObj calcStack2) {
 		StackManagement.ToggleCurrentStackNum();
 	}
 
+	/**
+	 * ExportStackToDisk(): Save the current stack contacts to the provided file
+	 * 
+	 * @param arg
+	 */
+	public static void exportStackToDisk(StackObj calcStack, String arg) {
+		String fileName = arg.trim();
+
+		// Return if no filename is given
+		if (arg.isEmpty()) {
+			Output.printColorln(Ansi.Color.RED, "Export requires a filename to be provided");
+			return;
+		}
+
+		// Ensure we have at least one item on the stack
+		if (calcStack.size() < 1) {
+			Output.printColorln(Ansi.Color.RED, "Export requires at least one item on the stack");
+			return;
+		}
+
+		Output.debugPrint("Export filename: '" + fileName + "'");
+
+		// If the file exists, then delete it
+		try {
+			File file = new File(fileName);
+			if (file.exists()) {
+				Output.debugPrint("'" + fileName + "' exists - deleting");
+				file.delete();
+			}
+		} catch (Exception ex) {
+			Output.printColorln(Ansi.Color.RED, "'" + fileName + "' exists and was not able to be deleted");
+			return;
+		}
+
+		//
+		try {
+			// Create the output filename and write the stack values to it
+			if (new File(fileName).createNewFile() == true) {
+				FileWriter fw = new FileWriter(new File(fileName));
+
+				for (int i = 0; i < calcStack.size(); i++) {
+					fw.write(String.valueOf(calcStack.get(i) + "\n"));
+				}
+
+				Output.printColorln(Ansi.Color.CYAN, "Export successful to '" + fileName + "'");
+
+				// Close the FileWriter and flush the data to the file
+				fw.close();
+			}
+
+		} catch (IOException ex) {
+			Output.printColorln(Ansi.Color.RED, "Could not export stack values to '" + fileName + "'");
+			return;
+		}
+
+	}
+
 	/**
 	 * LoadStackFromDisk(): Load the contents of a file into the stack. The file should have one stack item per line
 	 * 

src/test/java/org/fross/rpncalc/StackOperationsTest.java

@@ -33,6 +33,10 @@
 
 import java.io.File;
 import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
 import java.util.prefs.BackingStoreException;
 import java.util.prefs.Preferences;
 
@@ -163,6 +167,70 @@ void testLoadCommand() {
 		}
 	}
 
+	/**
+	 * Test stack output to file
+	 */
+	@Test
+	void textExport() {
+		String testFileName = "target/rpncalc.export";
+		File testFile = new File(testFileName);
+		Double[] testValues = { -1.0123, 2.0234, 3.0345, -15.0456, 2.0567, 17.0678, 38.0789, 53.0891, 14.0123, 73.0234, 72.0345, 72.0456, 10.0567, 83.0678,
+				-60.0789, 76.0890, 59.090, 30.0234, -42.0345, 89.0456, 30.0567, 44.0678, -31.0789 };
+
+		// Build the StackObject
+		StackObj stk = new StackObj();
+		for (int i = 0; i < testValues.length; i++) {
+			stk.push(testValues[i]);
+		}
+		assertEquals(23, stk.size());
+
+		// Delete the testFile if it exists
+		try {
+			testFile.delete();
+		} catch (Exception ex) {
+			Output.println("Testing Export: Issue deleting test file: ' " + testFileName + "'");
+		}
+
+		// Export the file and see if it looks OK
+		StackOperations.exportStackToDisk(stk, testFileName);
+		assertTrue(testFile.exists());
+		assertTrue(testFile.isFile());
+		assertTrue(testFile.length() > 0);
+
+		// Import the stack from the file and compare
+		try {
+			// Verify the filename provided is a file and can be read
+			if (new File(testFileName).canRead() && new File(testFileName).isFile()) {
+				// Read lines from the file into the ArrayList
+				ArrayList<String> linesRead = new ArrayList<>(Files.readAllLines(Paths.get(testFileName)));
+
+				// Test that read-from-file value = test value
+				for (int i = 0; i < testValues.length; i++) {
+					assertEquals(testValues[i].toString(), linesRead.get(i));
+				}
+			} else {
+				throw new IOException();
+			}
+		} catch (IOException ex) {
+			Output.printColorln(Ansi.Color.RED, "ERROR: Could not read from the file '" + testFileName + "'");
+			Output.printColorln(Ansi.Color.RED, "ERROR: Please note the file must be in lower case");
+
+		} catch (NumberFormatException ex) {
+			Output.printColorln(Ansi.Color.RED, "The data in '" + testFileName
+					+ "' can't be read as it is not in the correct format.\nThe import file format is simply one number per line");
+		}
+
+		// Delete the test import file
+		try {
+			File file = new File(testFileName);
+			file.delete();
+			assertFalse(testFile.exists());
+		} catch (Exception ex) {
+			Output.println("Testing Export: Issue deleting test file: ' " + testFileName + "'");
+		}
+
+	}
+
 	/**
 	 * Test import capabilities
 	 */
@@ -175,11 +243,12 @@ void testImport() {
 		try {
 			FileWriter fw = new FileWriter(new File(testFileName.toLowerCase()));
 
+			// Loop through the test values and compare
 			for (int i = 0; i < testValues.length; i++) {
 				fw.write(testValues[i] + "\n");
 			}
 
-			// Remove testfile
+			// Close the FileWriter
 			fw.close();
 
 		} catch (Exception ex) {
@@ -192,7 +261,6 @@ void testImport() {
 
 		// Verify the import values match the file data
 		for (int i = 0; i < testValues.length; i++) {
-			Output.println("Testing Import: TestValues:" + testValues[i] + "\t| StackValues: " + stk.get(i));
 			assertEquals(testValues[i], stk.get(i));
 		}