Whether LettuceConnectionFactory have version restrictions on redis and springboot?

Question

The project need a custom RedisConnectionFactory and finds a problem: when using LettuceConnectionFactory, the runtime always reports java.lang.NullPointerException, while JedisConnectionFactory can pass tests. I think that whether LettuceConnectionFactory have version restrictions on redis and springboot?

Developing environment:

Springboot: 2.1.0.release

redis:3.2.8

jdk8.

Java Code

@Component
@Configuration
public class RedisConfig {

    public LettuceConnectionFactory lettuceConnectionFactoryTest(){
        return new LettuceConnectionFactory(new RedisStandaloneConfiguration("127.0.0.1", 6379));
    }

    public JedisConnectionFactory jedisConnectionFactoryTest(){
        return new JedisConnectionFactory(new RedisStandaloneConfiguration("127.0.0.1", 6379));
    }

}

Test Code

@Autowired
private RedisConfig redisConfig;

@Autowired
private StringRedisTemplate redisTemplate;

@Test
public void test(){

    redisTemplate.setConnectionFactory(redisConfig.lettuceConnectionFactoryTest());
    ValueOperations<String, String> valueOperations = redisTemplate.opsForValue();
    valueOperations.set("test", "test123");
    System.out.println(valueOperations.get("test"));

}

Exception

java.lang.NullPointerException
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1085)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getConnection(LettuceConnectionFactory.java:1065)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getSharedConnection(LettuceConnectionFactory.java:865)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getConnection(LettuceConnectionFactory.java:340)
at org.springframework.data.redis.core.RedisConnectionUtils.doGetConnection(RedisConnectionUtils.java:132)
at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:95)
at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:82)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:211)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:184)
at org.springframework.data.redis.core.AbstractOperations.execute(AbstractOperations.java:95)
at org.springframework.data.redis.core.DefaultValueOperations.set(DefaultValueOperations.java:236)
at com.test.infrastructure.InfrastructureApplicationTests.test(InfrastructureApplicationTests.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)
at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Answer 1

The NullPointerException is occurring because LettuceConnectionFactory has not been initialised. It should be initialised by Spring Framework calling afterPropertiesSet() which is one of the standard bean lifecycle methods. That method isn't being called as your LettuceConnectionFactory isn't a bean due to a missing @Bean annotation on RedisConfig.lettuceConnectionFactoryTest().

Adding @Bean on RedisConfig.lettuceConnectionFactoryTest() should solve your problem. It will also allow you to inject LettuceConnectionFactory directly (into an @Autowired field in your test) rather than injecting RedisConfig and then calling lettuceConnectionFactoryTest() on it.