Identified depracations and updated the code

spring-cloud-task-samples/single-step-batch-job/src/test/java/io/spring/BatchJobApplicationTests.java

@@ -17,6 +17,7 @@
 package io.spring;
 
 import java.io.File;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.sql.SQLException;
@@ -26,16 +27,16 @@ import java.util.Map;
 
 import javax.sql.DataSource;
 
+import org.assertj.core.api.Assertions;
 import org.h2.tools.Server;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-//import org.springframework.batch.test.AssertFile;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.jdbc.DataSourceBuilder;
 import org.springframework.core.io.ClassPathResource;
-//import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.io.FileSystemResource;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.datasource.DriverManagerDataSource;
 import org.springframework.jdbc.datasource.init.ResourceDatabasePopulator;
@@ -145,9 +146,9 @@ public class BatchJobApplicationTests {
 	}
 
 	private void validateFileResult() throws Exception {
-		// AssertFile.assertLineCount(6, new FileSystemResource("./result.txt"));
-		// AssertFile.assertFileEquals(new ClassPathResource("testresult.txt"),
-		// new FileSystemResource(this.outputFile));
+		assertThat(Assertions.linesOf(this.outputFile, StandardCharsets.UTF_16).size()).isEqualTo(6);
+		assertThat(Assertions.contentOf((new ClassPathResource("testresult.txt")).getFile())
+			.equals(new FileSystemResource(this.outputFile)));
 	}
 
 	private void validateDBResult() {