TestNG执行测试用例的顺序

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.Assert;
import org.testng.Reporter;
import org.testng.annotations.*;

public class TestNG {
    private WebDriver driver;

    @BeforeClass
    public void beforeClass() throws InterruptedException {
        System.setProperty("webdriver.firefox.marionette",
                "src/main/resourcec/geckodriver.exe");
        String baiduHomePage;
        baiduHomePage = "https://www.baidu.com/";

        driver = new FirefoxDriver();
        driver.manage().window().maximize();
        driver.get(baiduHomePage);
        Thread.sleep(2000);
        Assert.assertEquals(driver.getTitle(), "百度一下，你就知道");
    }

    @Test(priority = 3)
    //预期会第3次执行
    public void testNG_1() throws InterruptedException {
        WebElement webElement = driver.findElement(By.xpath(".//*[@id='kw']"));
        webElement.clear();
        webElement.sendKeys("Selenium");

        driver.findElement(By.xpath(".//*[@id='su']")).click();
        Thread.sleep(3000);

        Reporter.log("搜索Selenium的测试用例");
        Assert.assertEquals(driver.getTitle(), "Selenium_百度搜索");
        driver.navigate().refresh();
    }

    @Test(priority = 2)
    //预期会第2次执行
    public void testNG_2() throws InterruptedException {
        WebElement webElement = driver.findElement(By.xpath(".//*[@id='kw']"));
        webElement.clear();
        webElement.sendKeys("JMeter");

        driver.findElement(By.xpath(".//*[@id='su']")).click();
        Thread.sleep(3000);

        Reporter.log("搜索JMeter的测试用例");
        Assert.assertEquals(driver.getTitle(), "JMeter_百度搜索");
        driver.navigate().refresh();
    }

    @Test(priority = 1)
    //预期会第1次执行
    public void testNG_3() throws InterruptedException {
        WebElement webElement = driver.findElement(By.xpath(".//*[@id='kw']"));
        webElement.clear();
        webElement.sendKeys("Appium");

        driver.findElement(By.xpath(".//*[@id='su']")).click();
        Thread.sleep(3000);

        Reporter.log("搜索Appium的测试用例");
        Assert.assertEquals(driver.getTitle(), "Appium_百度搜索");
        driver.navigate().refresh();
    }

    @AfterClass
    public void afterClass(){
        driver.close();
        driver.quit();
    }

}