1、编写类

package com.jacoco;

/**
 * @author ybwei
 * @Description
 * @date 2021/8/31 13:27
 **/
public class Add {
    public int add(int a, int b) {
        if (a == 20) {
            return 20;
        }
        return a + b;
    }
}

自行生成Test类快捷键，ctrl+shift+T或者在类中右键，选中Go To-->选择Test，弹窗中选中需要测试的方法，直接生成。

package com.jacoco;

import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

@Slf4j
public class AddTest {

    private static Add add=new Add();

    @BeforeEach
    void setUp() {
        log.info("setUp");
    }

    @AfterEach
    void tearDown() {
        log.info("tearDown");
    }

    @Test
    void add() {
        int sum = add.add(1, 2);
        assertEquals(3, sum);
    }
}

2、idea自带插件

注意： 测试的包名和开发的包名必须一致，否则会没有测试报告（报No coverage in ‘all classes in scope‘ in Intellij）。

执行Run 'AddTest' with Coverage

生成覆盖率

 3、jacoco插件

pom.xml

<build>
    <plugins>
        <plugin>
            <groupId>org.jacoco</groupId>
            <artifactId>jacoco-maven-plugin</artifactId>
            <version>0.8.7</version>
            <configuration>
                <destFile>target/test-coverage/jacoco-unit.exec</destFile>
                <dataFile>target/test-coverage/jacoco-unit.exec</dataFile>
            </configuration>
            <executions>
                <execution>
                    <id>default-prepare-agent</id>
                    <goals>
                        <goal>prepare-agent</goal>
                    </goals>
                </execution>
                <execution>
                    <id>jacoco-site</id>
                    <phase>test</phase>
                    <goals>
                        <goal>report</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

执行命令

mvn clean test -Dtest=com.jacoco.AddTest -Dmaven.test.failure.ignore=true verify

执行完成，在target/site/jacoco/index.html即可查看覆盖率图表。