完整代码Github地址： https://github.com/mgljava/jacoco-demo

Maven：Apache Maven是一个软件项目管理和理解工具。Maven基于项目对象模型(POM)的概念，可以从中心信息管理项目的构建、报告和文档

Jacoco：Java Code Coverage Library

1.创建Maven工程--》不多说。我用的是Intellij IDEA IDE

2.配置maven-compiler-plugin

<plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.6.1</version><configuration><skipMain>true</skipMain><skip>true</skip><source>1.8</source><target>1.8</target></configuration>
</plugin>

3.配置Jacoco-maven-plugins

<plugin><groupId>org.jacoco</groupId><artifactId>jacoco-maven-plugin</artifactId><version>${jacoco.version}</version><executions><execution><id>prepare-agent</id><goals><goal>prepare-agent</goal></goals></execution><execution><id>report</id><phase>prepare-package</phase><goals><goal>report</goal></goals></execution><execution><id>post-unit-test</id><phase>test</phase><goals><goal>report</goal></goals><configuration><dataFile>target/jacoco.exec</dataFile><outputDirectory>target/jacoco-report</outputDirectory></configuration></execution></executions><configuration><systemPropertyVariables><jacoco-agent.destfile>target/jacoco.exec</jacoco-agent.destfile></systemPropertyVariables></configuration>
</plugin>

4.编写业务代码，这里用作举例，就弄一个简单的计算类

package com.github.mgljava.calc;public class Calculator {public int add(int a, int b) {return a + b;}public int sub(int a, int b) {return a - b;}public int multi(int a, int b) {return a * b;}public int div(int a, int b) {return a / b;}public int switchCase(int a) {switch (a) {case 1:return 1;case 2:return 2;case 3:return 3;default:return 4;}}
}

5.编写测试类

package com.github.mgljava.calc;import static org.junit.Assert.assertEquals;import org.junit.Test;public class CalculatorTest {private Calculator calculator = new Calculator();@Testpublic void should_get_30_when_a_equal_20_and_b_equal_10() {// givenint a = 10;int b = 20;// whenfinal int addNumber = calculator.add(a, b);// thenassertEquals(30, addNumber);}@Testpublic void should_get_18_when_a_equal_20_and_b_equal_2() {// givenint a = 20;int b = 2;// whenfinal int subNumber = calculator.sub(a, b);// thenassertEquals(18, subNumber);}@Testpublic void should_get_6_when_a_equal_3_and_b_equal_2() {// givenint a = 3;int b = 2;// whenfinal int multiResult = calculator.multi(a, b);// thenassertEquals(6, multiResult);}@Testpublic void should_get_5_when_a_equal_10_and_b_equal_2() {// givenint a = 10;int b = 2;// whenfinal int divResult = calculator.div(a, b);// thenassertEquals(5, divResult);}@Testpublic void should_get_1_when_arg_is_1() {// givenint a = 1;// whenfinal int result = calculator.switchCase(a);// thenassertEquals(1, result);}@Testpublic void should_get_2_when_arg_is_2() {// givenint a = 2;// whenfinal int result = calculator.switchCase(a);// thenassertEquals(2, result);}@Testpublic void should_get_3_when_arg_is_3() {// givenint a = 3;// whenfinal int result = calculator.switchCase(a);// thenassertEquals(3, result);}@Testpublic void should_get_4_when_arg_is_4() {// givenint a = 4;// whenfinal int result = calculator.switchCase(a);// thenassertEquals(4, result);}
}

6.运行命令：mvn test ，可以在下图中看到生成的测试报告目录

7.可以在浏览器中看到测试报告：