TestNG 中 ParallelMode.METHODS,ParallelMode.CLASSES，ParallelMode.TESTS区别

在 TestNG 中，可以设置testNG 是否是多线程的，这时候 需要用到ParallelMode来定义
那么ParallelMode.METHODS,ParallelMode.CLASSES， ParallelMode.TESTS 有什么区别呢？

结论：
ParallelMode.METHODS：一个线程负责一个@Test标签的程序，多个并行时，每个class，method之间的线程ID都不一样
ParallelMode.CLASSES：一个线程 负责一个class里面所有的带有@Test标签的method，多个并行时，每个class之间的线程id不一样，但是同一个class里的@Test的method线程id是一样的
ParallelMode.TESTS：一个线程负责一个TestNG.xml中的一个< Test >标签，多个并行时，每个 < Test > 所包含的class，method之间的线程ID 是一致的，但是 每个< Test > 之间的线程ID是不一致的

做个实验：
ParallelMode.METHODS：

package com.howtodoinjava.parallelism;import org.testng.annotations.AfterClass;import org.testng.annotations.AfterMethod;import org.testng.annotations.BeforeClass;import org.testng.annotations.BeforeMethod;import org.testng.annotations.Test;public class ParallelClassesTestTwo {    @BeforeClass    public void beforeClass() {        long id = Thread.currentThread().getId();        System.out.println("222 Before test-class. Thread id is: " + id);    }    @BeforeMethod    public void beforeMethod() {        long id = Thread.currentThread().getId();        System.out.println("222 Before test-method. Thread id is: " + id);    }    @Test    public void testMethodOne() {        long id = Thread.currentThread().getId();        System.out.println("222 Sample test-method One. Thread id is: " + id);    }    @Test    public void testMethodTwo() {        long id = Thread.currentThread().getId();        System.out.println("222 Sample test-method Two. Thread id is: " + id);    }    @AfterMethod    public void afterMethod() {        long id = Thread.currentThread().getId();        System.out.println("222 After test-method. Thread id is: " + id);    }    @AfterClass    public void afterClass() {        long id = Thread.currentThread().getId();        System.out.println("222 After test-class. Thread id is: " + id);    }}

对应的testNG.xml 如下，

<suite name="Test-method Suite" parallel="methods" thread-count="2">    <test name="Test-method test" group-by-instances="true">        <classes>        <class name="com.howtodoinjava.parallelism.ParallelClassesTestTwo" />        </classes>    </test></suite>

得到的结果为：

[TestNG] Running:  /home/fiona/UIAutomation-fiona-new/Test/src/methods-test-testng.xml222 Before test-class. Thread id is: 11222 Before test-method. Thread id is: 10222 Before test-method. Thread id is: 11222 Sample test-method Two. Thread id is: 11222 Sample test-method One. Thread id is: 10222 After test-method. Thread id is: 10222 After test-method. Thread id is: 11222 After test-class. Thread id is: 11===============================================Test-method SuiteTotal tests run: 2, Failures: 0, Skips: 0===============================================

ParallelMode.CLASSES：

package com.howtodoinjava.parallelism;import org.testng.annotations.AfterClass;import org.testng.annotations.AfterMethod;import org.testng.annotations.BeforeClass;import org.testng.annotations.BeforeMethod;import org.testng.annotations.Test;public class ParallelClassesTestTwo {    @BeforeClass    public void beforeClass() {        long id = Thread.currentThread().getId();        System.out.println("222 Before test-class. Thread id is: " + id);    }    @BeforeMethod    public void beforeMethod() {        long id = Thread.currentThread().getId();        System.out.println("222 Before test-method. Thread id is: " + id);    }    @Test    public void testMethodOne() {        long id = Thread.currentThread().getId();        System.out.println("222 Sample test-method One. Thread id is: " + id);    }    @Test    public void testMethodTwo() {        long id = Thread.currentThread().getId();        System.out.println("222 Sample test-method Two. Thread id is: " + id);    }    @AfterMethod    public void afterMethod() {        long id = Thread.currentThread().getId();        System.out.println("222 After test-method. Thread id is: " + id);    }    @AfterClass    public void afterClass() {        long id = Thread.currentThread().getId();        System.out.println("222 After test-class. Thread id is: " + id);    }}

package com.howtodoinjava.parallelism;import org.testng.annotations.AfterClass;import org.testng.annotations.AfterMethod;import org.testng.annotations.BeforeClass;import org.testng.annotations.BeforeMethod;import org.testng.annotations.Test;public class ParallelMethodTest {    @BeforeClass    public void beforeClass(){        long id = Thread.currentThread().getId();        System.out.println("111 Before class-method. Thread id is: " + id);    }     @BeforeMethod        public void beforeMethod() {            long id = Thread.currentThread().getId();            System.out.println("111 Before test-method. Thread id is: " + id);        }        @Test        public void testMethodsOne() {            long id = Thread.currentThread().getId();            System.out.println("111 Simple test-method One. Thread id is: " + id);        }        @AfterMethod        public void afterMethod() {            long id = Thread.currentThread().getId();            System.out.println("111 After test-method. Thread id is: " + id);        }        @AfterClass        public void AfterClass(){            long id = Thread.currentThread().getId();            System.out.println("111 After class-method. Thread id is: " + id);        }}

<suite name="Test-method Suite" parallel="classes" thread-count="2">    <test name="Test-method test" group-by-instances="true">        <classes>            <class name="com.howtodoinjava.parallelism.ParallelMethodTest" />            <class name="com.howtodoinjava.parallelism.ParallelClassesTestTwo" />        </classes>    </test></suite>

In the result , you could clearly to see that thread 10 is only working for the 111, and thread 11 working for the 222.

[TestNG] Running:  /home/fiona/UIAutomation-fiona-new/Test/src/methods-test-testng.xml111 Before class-method. Thread id is: 10111 Before test-method. Thread id is: 10111 Simple test-method One. Thread id is: 10111 After test-method. Thread id is: 10111 After class-method. Thread id is: 10222 Before test-class. Thread id is: 11222 Before test-method. Thread id is: 11222 Sample test-method One. Thread id is: 11222 After test-method. Thread id is: 11222 Before test-method. Thread id is: 11222 Sample test-method Two. Thread id is: 11222 After test-method. Thread id is: 11222 After test-class. Thread id is: 11===============================================Test-method SuiteTotal tests run: 3, Failures: 0, Skips: 0===============================================

ParallelMode.TESTS：
Same java code as above, with different testNG.xml:
1> 在同一个test标签中：

<suite name="Test-method Suite" parallel="tests" thread-count="2">    <test name="Test-method test" group-by-instances="true">        <classes>            <class name="com.howtodoinjava.parallelism.ParallelMethodTest" />            <class name="com.howtodoinjava.parallelism.ParallelClassesTestTwo" />        </classes>    </test>    </suite>

得到如下结果：

[TestNG] Running:  /home/fiona/UIAutomation-fiona-new/Test/src/methods-test-testng.xml111 Before class-method. Thread id is: 10111 Before test-method. Thread id is: 10111 Simple test-method One. Thread id is: 10111 After test-method. Thread id is: 10111 After class-method. Thread id is: 10222 Before test-class. Thread id is: 10222 Before test-method. Thread id is: 10222 Sample test-method One. Thread id is: 10222 After test-method. Thread id is: 10222 Before test-method. Thread id is: 10222 Sample test-method Two. Thread id is: 10222 After test-method. Thread id is: 10222 After test-class. Thread id is: 10===============================================Test-method SuiteTotal tests run: 3, Failures: 0, Skips: 0===============================================

2> 在不同的Test标签中

<suite name="Test-method Suite" parallel="tests" thread-count="2">    <test name="Test-method test" group-by-instances="true">        <classes>            <class name="com.howtodoinjava.parallelism.ParallelMethodTest" />        </classes>    </test>    <test name="Test-method test2" group-by-instances="true">        <classes>            <class name="com.howtodoinjava.parallelism.ParallelClassesTestTwo" />        </classes>    </test></suite>

得到结果如下：多线程出现

[TestNG] Running:  /home/fiona/UIAutomation-fiona-new/Test/src/methods-test-testng.xml222 Before test-class. Thread id is: 11111 Before class-method. Thread id is: 10111 Before test-method. Thread id is: 10222 Before test-method. Thread id is: 11111 Simple test-method One. Thread id is: 10222 Sample test-method One. Thread id is: 11222 After test-method. Thread id is: 11111 After test-method. Thread id is: 10111 After class-method. Thread id is: 10222 Before test-method. Thread id is: 11222 Sample test-method Two. Thread id is: 11222 After test-method. Thread id is: 11222 After test-class. Thread id is: 11===============================================Test-method SuiteTotal tests run: 3, Failures: 0, Skips: 0===============================================