DOC-4445 server management command examples (#4056)

* DOC-4445 server management command examples

* DOC-4445 implemented info command example with Jedis class

* Apply suggestions from code review

Co-authored-by: M Sazzadul Hoque <[email protected]>

* DOC-4445 implemented feedback

---------

Co-authored-by: M Sazzadul Hoque <[email protected]>

Author: andy-stark-redis

src/test/java/io/redis/examples/CmdsServerMgmtExample.java

@@ -0,0 +1,58 @@
+// EXAMPLE: cmds_servermgmt
+// REMOVE_START
+package io.redis.examples;
+
+import org.junit.Assert;
+import org.junit.Test;
+// REMOVE_END
+import java.util.Set;
+
+import redis.clients.jedis.Jedis;
+// HIDE_START
+import redis.clients.jedis.UnifiedJedis;
+
+public class CmdsServerMgmtExample {
+    @Test
+    public void run() {
+        UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379");
+// HIDE_END
+
+        // STEP_START flushall
+        // REMOVE_START
+        jedis.set("testkey1", "1");
+        jedis.set("testkey2", "2");
+        jedis.set("testkey3", "3");
+        // REMOVE_END
+        String flushAllResult1 = jedis.flushAll();
+        System.out.println(flushAllResult1); // >>> OK
+
+        Set<String> flushAllResult2 = jedis.keys("*");
+        System.out.println(flushAllResult2); // >>> []
+        // STEP_END
+        // REMOVE_START
+        Assert.assertEquals("OK", flushAllResult1);
+        Assert.assertEquals("[]", flushAllResult2.toString());
+        // REMOVE_END
+
+        // STEP_START info
+        // Note: you must use the `Jedis` class to access the `info`
+        // command rather than `UnifiedJedis`.
+        Jedis jedis2 = new Jedis("redis://localhost:6379");
+
+        String infoResult = jedis2.info();
+        
+        // Check the first 8 characters of the result (the full `info` string
+        // is much longer than this).
+        System.out.println(infoResult.substring(0, 8)); // >>> # Server
+
+        jedis2.close();
+        // STEP_END
+        // REMOVE_START
+        Assert.assertEquals("# Server", infoResult.substring(0, 8));
+        // REMOVE_END
+        
+// HIDE_START
+        jedis.close();
+    }
+}
+// HIDE_END