JUNIT:未调用setUp()

JUNIT:未调用setUp(),junit,nullpointerexception,junit5,Junit,Nullpointerexception,Junit5,Junit的setUp()未被调用,因此当测试方法尝试访问BankAccount对象时,会抛出NullPointerException 我的设置()有什么问题 以下是测试代码: package my_package; import static org.junit.jupiter.api.Assertions.*; import org.junit.Before; import org.junit.jupiter.api.BeforeEach; import org.junit.jupiter

Junit的
setUp()
未被调用,因此当测试方法尝试访问
BankAccount
对象时,会抛出
NullPointerException

我的
设置()有什么问题

以下是测试代码:

package my_package;

import static org.junit.jupiter.api.Assertions.*;
import org.junit.Before;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

class BankAccountTest {
    private BankAccount acc;

    @Before
    public void setUp(){
        acc = new BankAccount(100);
    }

    @Test
    void testDeposit() {
        acc.deposit(50);
        assertEquals(acc.getBalance(), 50);
    }

    @Test
    void testWithdraw() {
        acc.withdraw(50);
        assertEquals(acc.getBalance(), 25);
    }

    @Test
    void testWithdrawLimit() {
        assertFalse(acc.withdraw(10000));
        assertEquals(100, acc.getBalance());

        assertTrue(acc.withdraw(1));
        assertEquals(acc.getBalance(),99);
    }
}
下面是应用程序代码

package my_package;

public class BankAccount {

    private int balance;

    public BankAccount(int i) {
        balance=i;
    }

    public BankAccount() {
        balance=0;
    }

    public void deposit(int amount) {
        balance += amount;
    }

    public boolean withdraw(int amount) {
        boolean allow = balance >= amount;
        if(allow) {
            balance -= amount;  
        }
        return allow;
    }

    public int getBalance() {
        return balance;
    }
}
堆栈跟踪:

java.lang.NullPointerException
    at bank_app_lynda_tdd.BankAccountTest.testWithdraw(BankAccountTest.java:23)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:628)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:117)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:184)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:180)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:127)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:68)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1378)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1378)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
    at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
    at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:137)
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
将注释替换为

解释

setUp
方法使用JUnit4中的
@Before
注释

但是您的测试是为JUnit5编写的(用于测试方法)


发件人:

之前的@和在之后的@不再存在;改为在每次之前使用
@和每次
之后使用
@


我看不出你的代码有任何明显的错误。你还可以展示一个运行完整stacktrace的示例吗?当然,我还提供了一些代码供其他人重现错误。是的,你的代码示例很棒!至于一些提示:添加
System.out.println('HERE')
或类似于
setUp()
中的代码,以查看是否调用了它。有关其他调试技巧,请阅读以获取有关如何调试代码的更多技巧。将
@之前的
注释替换为@code peedient我已经发布了答案。谢谢