Rework the delete everything in Redis example

persistence-modules/redis/README.md

@@ -4,3 +4,4 @@
 - [Introduction to Lettuce – the Java Redis Client](https://www.baeldung.com/java-redis-lettuce)
 - [List All Available Redis Keys](https://www.baeldung.com/redis-list-available-keys)
 - [Spring Data Redis’s Property-Based Configuration](https://www.baeldung.com/spring-data-redis-properties)
+- [Delete Everything in Redis](https://www.baeldung.com/redis-delete-data)

persistence-modules/redis/pom.xml

@@ -33,7 +33,8 @@
         <dependency>
             <groupId>redis.clients</groupId>
             <artifactId>jedis</artifactId>
-            </dependency>
+            <version>3.3.0</version>
+        </dependency>
         <dependency>
             <groupId>com.github.kstyrc</groupId>
             <artifactId>embedded-redis</artifactId>

persistence-modules/redis/src/test/java/com/baeldung/redis/deleteeverything/DeleteEverythingInRedisIntegrationTest.java

@@ -0,0 +1,91 @@
+package com.baeldung.redis.deleteeverything;
+
+import org.junit.*;
+import redis.clients.jedis.Jedis;
+import redis.embedded.RedisServer;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+public class DeleteEverythingInRedisIntegrationTest {
+    private Jedis jedis;
+    private RedisServer redisServer;
+    private int port;
+
+    @Before
+    public void setUp() throws IOException {
+
+        // Take an available port
+        ServerSocket s = new ServerSocket(0);
+        port = s.getLocalPort();
+        s.close();
+
+        redisServer = new RedisServer(port);
+        redisServer.start();
+
+        // Configure JEDIS
+        jedis = new Jedis("localhost", port);
+    }
+
+    @After
+    public void destroy() {
+        redisServer.stop();
+    }
+
+    @Test
+    public void whenPutDataIntoRedis_thenCanBeFound() {
+        String key = "key";
+        String value = "value";
+
+        jedis.set(key, value);
+        String received = jedis.get(key);
+
+        assertEquals(value, received);
+    }
+
+    @Test
+    public void whenPutDataIntoRedisAndThenFlush_thenCannotBeFound() {
+        String key = "key";
+        String value = "value";
+
+        jedis.set(key, value);
+
+        jedis.flushDB();
+
+        String received = jedis.get(key);
+
+        assertNull(received);
+    }
+
+    @Test
+    public void whenPutDataIntoMultipleDatabases_thenFlushAllRemovesAll() {
+        // add keys in different databases
+        jedis.select(0);
+        jedis.set("key1", "value1");
+        jedis.select(1);
+        jedis.set("key2", "value2");
+
+        // we'll find the correct keys in the correct dbs
+        jedis.select(0);
+        assertEquals("value1", jedis.get("key1"));
+        assertNull(jedis.get("key2"));
+
+        jedis.select(1);
+        assertEquals("value2", jedis.get("key2"));
+        assertNull(jedis.get("key1"));
+
+        // then, when we flush
+        jedis.flushAll();
+
+        // the keys will have gone
+        jedis.select(0);
+        assertNull(jedis.get("key1"));
+        assertNull(jedis.get("key2"));
+        jedis.select(1);
+        assertNull(jedis.get("key1"));
+        assertNull(jedis.get("key2"));
+    }
+}