LettuceConnectionFactory是否对redis和SpringBoot有版本限制？

Question

该项目需要一个自定义的RedisConnectionFactory，并发现了一个问题：当使用LettuceConnectionFactory时，运行时总是报告java.lang.NullPointerException，而JedisConnectionFactory可以通过测试。我想LettuceConnectionFactory是否对redis和Springboot有版本限制？

开发环境：

SpringBoot:2.1.0.发行版

Redis:3.2.8

@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));
    }

}

@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"));

}

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

出现NullPointerException是因为LettuceConnectionFactory尚未初始化。它应该由Spring框架调用afterPropertiesSet()初始化，这是标准bean生命周期方法之一。由于redisconfig.lettuceConnectionFactoryTest()上缺少@bean注释，因此没有调用该方法，因为LettuceConnectionFactory不是bean。

在redisconfig.lettuceConnectionFactoryTest()上添加@bean应该可以解决您的问题。它还允许您直接注入LettuceConnectionFactory（到测试中的@autowired字段中），而不是注入redisconfig然后调用LettuceConnectionFactory()。