我有以下测试:
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
@TestPropertySource(value = "classpath:testApplication.properties")
public class ESJavaAPITests {
@Resource
private Environment environment;
private final String CLUSTER_NAME = environment.getProperty("ES.cluster.name");
}
该 properties 位于 test/java/resources/testApplication.properties
,看起来像这样:
ES.host = localhost
ES.port = 9300
ES.cluster.name = 2m3d
但是我继续得到 NullPointerException
第25行,这正是 CLUSTER_NAME
初始化的行:
com.example.estrans.ESJavaAPITests上的java.lang.NullPointerException . (ESJavaAPITests.java:25)at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)at在org.junit.runners.BlockJUnit4ClassRunner.createTest(BlockJUnit4ClassRunner.java:217)的org.jun.Rerner . .springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227)位于org.junit.internal.runners的org.springframework.test.context.junit4.SpringJUnit4ClassRunner $ 1.runReflectiveCall(SpringJUnit4ClassRunner.java:287) . 在org.springframework.test.context.junit4的org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)的model.ReflectiveCallable.run(ReflectiveCallable.java:12) . SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)位于org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)org.junit.runners.ParentRunner $ 3.run(ParentRunner.java:290)at org.junit.runners.ParentRunner $ 1.schedule(ParentRunner.java:71)org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)org.junit.runners.ParentRunner.access $ 000(ParentRunner.java: 58)org.jun.runners.ParentRunner $ 2.evaluate(ParentRunner.java:268)org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)org.springframework.test . org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner)中的org.junit.runners.ParentRunner.run(ParentRunner.java:363)中的context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) . java:191)在com.intellij的org.junit.runner.JUnitCore.run(JUnitCore.java:137) . junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117)at com.intellij.rt.exe.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:234)at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter . java:74)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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
为什么选择NPE?
1 回答
你得到一个NPE,因为在你的
CLUSTER_NAME
字段被初始化时,环境是null
因为Spring还没有时间自动加载类 - 在创建测试类实例时初始化了CLUSTER_NAME
. 您应该使用@Value("${ES.cluster.name}")
代替: