public class StringRedisTemplate extends RedisTemplate<String, String> {

	/**
	 * Constructs a new <code>StringRedisTemplate</code> instance. {@link #setConnectionFactory(RedisConnectionFactory)}
	 * and {@link #afterPropertiesSet()} still need to be called.
	 */
	public StringRedisTemplate() {
		setKeySerializer(RedisSerializer.string());
		setValueSerializer(RedisSerializer.string());
		setHashKeySerializer(RedisSerializer.string());
		setHashValueSerializer(RedisSerializer.string());
	}
    
}

public class RedisTemplate<K, V> extends RedisAccessor implements RedisOperations<K, V>, BeanClassLoaderAware {
    // 省略其他源碼
	private @Nullable RedisSerializer<?> defaultSerializer;
	private @Nullable ClassLoader classLoader;

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.redis.core.RedisAccessor#afterPropertiesSet()
	 */
	@Override
	public void afterPropertiesSet() {

		super.afterPropertiesSet();

		boolean defaultUsed = false;

		if (defaultSerializer == null) {

			defaultSerializer = new JdkSerializationRedisSerializer(
					classLoader != null ? classLoader : this.getClass().getClassLoader());
		}

		if (enableDefaultSerializer) {

			if (keySerializer == null) {
				keySerializer = defaultSerializer;
				defaultUsed = true;
			}
			// 省略其他源碼
		}

		if (enableDefaultSerializer && defaultUsed) {
			Assert.notNull(defaultSerializer, "default serializer null and not all serializers initialized");
		}

		if (scriptExecutor == null) {
			this.scriptExecutor = new DefaultScriptExecutor<>(this);
		}

		initialized = true;
	}
	// 省略其他源碼
    
}

@Slf4j
@SpringBootTest
class RedisDifferentTemplateTest {
	@Resource
	private RedisTemplate<String, Object> redisTemplate;

	@Resource
	private StringRedisTemplate stringRedisTemplate;

	@Test
	void testSimple() {
		redisTemplate.opsForValue().set("myWeb", "www.choupangxia.com");
		Assertions.assertEquals("www.choupangxia.com", redisTemplate.opsForValue().get("myWeb"));

		Assertions.assertEquals("www.choupangxia.com",stringRedisTemplate.opsForValue().get("myWeb"));
	}
}

@BeforeEach
void init() {
	redisTemplate.setKeySerializer(RedisSerializer.string());
}

@BeforeEach
void init() {
	redisTemplate.setKeySerializer(RedisSerializer.string());
	redisTemplate.setValueSerializer(RedisSerializer.string());
}