如何在 java 中的 mockito 中为 Map 对象创建参数捕获器？

Question

如何创建参数捕获器Map<String, SomeCustomClass>？我的代码遵循以下模式：import java.util.HashMap;import java.util.Map;public class CompoundClass {   public CompoundClass (String a, String b){       this.a = a;       this.b = b;   }   public String a;   public String b;}public class SubClass {    public void doSomeThingSubClass(Map<String, CompoundClass> mapSb) {        ...    }}public class Example {    public SubClass sb;    public Example(SubClass sb) {        this.sb = sb;    }    public void doSomeThing () {        Map<String, CompoundClass> mapSb = new HashMap<>();        mapSb.put("x", new CompoundClass("aa","bb"));        sb.doSomeThingSubClass(mapSb);    }}而且我想测试是否调用了该方法doSomethingSubClass(mapSb)，因此我需要能够检查它被调用的参数。为此，我进行了以下单元测试：@Testvoid TestDoSomehing(){    SubClass sb = mock(SubClass.class);        Example ex = new Example(sb);        ArgumentCaptor<Map<String, CompoundClass>> argCaptor = ArgumentCaptor.forClass(Map<String, CompoundClass>.class);    ex.doSomeThing();    verify(sb).doSomeThingSubClass(argCaptor.capture());        System.out(argCaptor.getValue().get('x').a);}问题是 argCaptor 的上述初始化会产生以下错误消息：“无法从参数化类型中选择”。因此，问题是如何以正确的方式声明一个映射对象的参数捕获器的初始化，例如Map<String, SomeCustomeClass>？提前致谢！

Answer 1

你可以这样做：

与@SuppressWarnings("未选中")

  @Test

  @SuppressWarnings("unchecked")

  void TestDoSomething(){

    SubClass sb = mock(SubClass.class);

    Example ex = new Example(sb);

    ArgumentCaptor<Map<String, CompoundClass>> argCaptor = ArgumentCaptor.forClass(Map.class);

    ex.doSomeThing();

    verify(sb).doSomeThingSubClass(argCaptor.capture());

    System.out.println(argCaptor.getValue().get("x").a);

  }

或使用 junit5 和 @Captor 注释：

import static org.mockito.Mockito.mock;

import static org.mockito.Mockito.verify;

import java.util.HashMap;

import java.util.Map;

import org.junit.jupiter.api.Test;

import org.junit.jupiter.api.TestInstance;

import org.junit.jupiter.api.TestInstance.Lifecycle;

import org.junit.jupiter.api.extension.ExtendWith;

import org.mockito.ArgumentCaptor;

import org.mockito.Captor;

import org.mockito.junit.jupiter.MockitoExtension;

@ExtendWith(MockitoExtension.class)

@TestInstance(Lifecycle.PER_METHOD)

public class TestDoSomething {

  @Captor

  private ArgumentCaptor<Map<String, CompoundClass>> argCaptor;

  @Test

  void TestDoSomething2(){

    SubClass sb = mock(SubClass.class);

    Example ex = new Example(sb);

    ex.doSomeThing();

    verify(sb).doSomeThingSubClass(argCaptor.capture());

    System.out.println(argCaptor.getValue().get("x").a);

  }

}

Answer 2

可以使用 Mockito 的Captor注解来声明ArgumentCaptor.

例如，以下测试编译并输出aa：

@Captor

private ArgumentCaptor<Map<String, CompoundClass>> argCaptor;

@Test

void TestDoSomehing(){

    MockitoAnnotations.initMocks(this);

    SubClass sb = mock(SubClass.class);

    Example ex = new Example(sb);

    ex.doSomeThing();

    verify(sb).doSomeThingSubClass(argCaptor.capture());

    System.out.println(argCaptor.getValue().get("x").a);

}

从Javadocs：

使用注释的优点之一@Captor是您可以避免与捕获复杂泛型类型相关的警告。