本篇博文我们将给出示例理解如何在Maven工程中配置Jacoco和如何使用Jacoco查看代码覆盖报告~

Jacoco是一个开源的Java代码覆盖率工具，Jacoco可以嵌入到Ant 、Maven中，并提供了EclEmma Eclipse插件,也可以使用JavaAgent技术监控Java程序。很多第三方的工具提供了对Jacoco的集成，如sonar、Jenkins等。

Maven工程

创建Maven工程

打开Eclipse，File->New->Project->Maven Project，新建一个Maven工程~

点击“Next”按钮，然后填写groupId和artifactId信息后点击"Finish"按钮即可~

groupId -->  com.xxx.tutorial

artifactId --> jacoco-demo

配置Jacoco

添加maven-complier-plugin

    				
     
      org.apache.maven.plugins
     				
     
      maven-compiler-plugin
     				
     
      3.6.1
     				
     					
      
       true
      					
      
       true
      					
      1.7					
      
       1.7
      				
     			
    

添加jacoco-maven-plugin

    				
     
      org.jacoco
     				
     
      jacoco-maven-plugin
     				
     
      ${jacoco.version}
     				
     					
      						
       
        prepare-agent
       						
       							
        
         prepare-agent
        						
       					
      					
      						
       
        report
       						
       
        prepare-package
       						
       							
        
         report
        						
       					
      					
      						
       
        post-unit-test
       						
       
        test
       						
       							
        
         report
        						
       						
       							
        
         target/jacoco.exec
        							
        
         target/jacoco-ut
        						
       					
      				
     				
     					
      						
       
        target/jacoco.exec
       					
      				
     			
    

在这里，我们将单元测试结果的输出目录确定为target/jacoco-ut目录下~

完整的pom.xml

    	
     
      4.0.0
     	
     
      com.xxx.tutorial
     	
     
      jacoco-demo
     	
     
      0.0.1-SNAPSHOT
     	
     		
      
       0.7.5.201505241946
      		
      
       4.12
      	
     	
     		
      			
       
        junit
       			
       
        junit
       			
       
        ${junit.version}
       			
       
        test
       		
      	
     	
     		
      			
       				
        
         org.apache.maven.plugins
        				
        
         maven-compiler-plugin
        				
        
         3.6.1
        				
        					
         
          true
         					
         
          true
         					
         1.7					
         
          1.7
         				
        			
       			
       				
        
         org.jacoco
        				
        
         jacoco-maven-plugin
        				
        
         ${jacoco.version}
        				
        					
          
          
           prepare-agent
           
           
           
            prepare-agent
            
           
         					
          
          
           report
           
          
           prepare-package
           
           
           
            report
            
           
         					
          
          
           post-unit-test
           
          
           test
           
           
           
            report
            
           
           
           
            target/jacoco.exec
            
           
            target/jacoco-ut
            
           
         				
        				
        					
          
          
           target/jacoco.exec
           
         				
        			
       		
      	
     
    

编写代码

Calculator.java

package com.xxx.tutorial;/** *  * @author wangmengjun * */public class Calculator {	public int add(int a, int b) {		return a + b;	}	public int sub(int a, int b) {		return a - b;	}}

Calculator_Test.java

package com.xxx.tutorial;import org.junit.Assert;import org.junit.Test;/** *  * @author wangmengjun * */public class Calculator_Test {	private Calculator instance = new Calculator();	@Test	public void testAdd() {		int a = 10;		int b = 20;		int expected = 30;		Assert.assertEquals(expected, instance.add(a, b));	}	@Test	public void testSub() {		int a = 10;		int b = 20;		int expected = -10;		Assert.assertEquals(expected, instance.sub(a, b));	}}

代码结构如下：

运行并查看Jacoco报告

运行Maven test

执行Maven test， 控制台输出如下结果：

[INFO] Scanning for projects...[INFO]                                                                         [INFO] ------------------------------------------------------------------------[INFO] Building jacoco-demo 0.0.1-SNAPSHOT[INFO] ------------------------------------------------------------------------[INFO] [INFO] --- jacoco-maven-plugin:0.7.5.201505241946:prepare-agent (prepare-agent) @ jacoco-demo ---[INFO] argLine set to -javaagent:D:\\java_tools\\Reponsitories\\Maven\\org\\jacoco\\org.jacoco.agent\\0.7.5.201505241946\\org.jacoco.agent-0.7.5.201505241946-runtime.jar=destfile=F:\\JavaDeveloper\\workspaces\\SpringMVCDubboExample\\jacoco-demo\\target\\jacoco.exec[INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ jacoco-demo ---[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent![INFO] Copying 0 resource[INFO] [INFO] --- maven-compiler-plugin:3.6.1:compile (default-compile) @ jacoco-demo ---[INFO] Not compiling main sources[INFO] [INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ jacoco-demo ---[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent![INFO] Copying 0 resource[INFO] [INFO] --- maven-compiler-plugin:3.6.1:testCompile (default-testCompile) @ jacoco-demo ---[INFO] Not compiling test sources[INFO] [INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ jacoco-demo ---[INFO] Surefire report directory: F:\JavaDeveloper\workspaces\SpringMVCDubboExample\jacoco-demo\target\surefire-reports------------------------------------------------------- T E S T S-------------------------------------------------------Running com.xxx.tutorial.Calculator_TestTests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.134 secResults :Tests run: 2, Failures: 0, Errors: 0, Skipped: 0[INFO] [INFO] --- jacoco-maven-plugin:0.7.5.201505241946:report (post-unit-test) @ jacoco-demo ---[INFO] Analyzed bundle 'jacoco-demo' with 1 classes[INFO] ------------------------------------------------------------------------[INFO] BUILD SUCCESS[INFO] ------------------------------------------------------------------------[INFO] Total time: 4.972 s[INFO] Finished at: 2017-06-16T21:02:30+08:00[INFO] Final Memory: 15M/244M[INFO] ------------------------------------------------------------------------

我们可以看到target目录下，已经生成了Jacoco的单元测试结果报告~

查看Jacoco报告

打开浏览器，在URL栏输入<工程地址>/target/jacoco-ut/index.html，如：

点击"com.xxx.tutorial"链接，查看这个com.xxx.tutorial包下的类。

再点击"Calculator"链接，展示Calculator类的方法信息~

再点击任何方法的连接，将会出现该类代码覆盖的情况：

绿色的表示覆盖到的，如果没有覆盖则会用红色背景表示

至此，

在Maven工程中配置Jacoco插件，运行并查看执行报告结果的示例就完成了~

另外，如果Eclipse工程中安装了EclEmma插件，执行测试类，

也能得到相应的结果，如：