More work on data file split/join, and added a test.

src/test/java/org/qortal/test/DataTests.java

@@ -0,0 +1,45 @@
+package org.qortal.test;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.repository.DataException;
+import org.qortal.storage.DataFile;
+import org.qortal.test.common.Common;
+
+import static org.junit.Assert.*;
+
+public class DataTests extends Common {
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+	}
+
+	@Test
+	public void testSplitAndJoin() {
+		String dummyDataString = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
+		DataFile dataFile = new DataFile(dummyDataString.getBytes());
+		assertTrue(dataFile.exists());
+		assertEquals(62, dataFile.size());
+		assertEquals("3eyjYjturyVe61grRX42bprGr3Cvw6ehTy4iknVnosDj", dataFile.base58Digest());
+
+		// Split into 7 chunks, each 10 bytes long
+		dataFile.split(10);
+		assertEquals(7, dataFile.chunkCount());
+
+		// Delete the original file
+		dataFile.delete();
+		assertFalse(dataFile.exists());
+		assertEquals(0, dataFile.size());
+
+		// Now rebuild the original file from the chunks
+		assertEquals(7, dataFile.chunkCount());
+		dataFile.join();
+
+		// Validate that the original file is intact
+		assertTrue(dataFile.exists());
+		assertEquals(62, dataFile.size());
+		assertEquals("3eyjYjturyVe61grRX42bprGr3Cvw6ehTy4iknVnosDj", dataFile.base58Digest());
+	}
+
+}