Selenium firefox 路径设置问题

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;

public class FirefoxDirectory {
WebDriver driver=null;

@Before
public void setUp() throws Exception {
System.setProperty("webdriver.firefox.bin", "D:\\firefox\\firefox.exe");
driver=new FirefoxDriver();
driver.get("http://www.baidu.com");
driver.manage().window().maximize();
}

@After
public void tearDown() throws Exception {
driver.quit();
}

@Test
public void test() throws InterruptedException {
//test content
}
}

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.remote.DesiredCapabilities;

public class FirefoxDirectory {
    WebDriver driver=null;

    @Before
    public void setUp() throws Exception {
        DesiredCapabilities ffcapability = DesiredCapabilities.firefox();
        ffcapability.setCapability("firefox_binary", "D:\\firefox\\firefox.exe");
        driver=new FirefoxDriver(ffcapability);
        driver.get("http://www.baidu.com");
        driver.manage().window().maximize();
    }

    @After
    public void tearDown() throws Exception {
        driver.quit();
    }

    @Test
    public void test() throws InterruptedException {
        //test content
    }
}

import java.io.File;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxBinary;
import org.openqa.selenium.firefox.FirefoxDriver;

public class FirefoxDirectory {
    WebDriver driver=null;

    @Before
    public void setUp() throws Exception {
        File file = new File("D:\\firefox\\firefox.exe");
        FirefoxBinary firefoxbin = new FirefoxBinary(file);
        driver=new FirefoxDriver(firefoxbin,null);
        driver.get("http://www.baidu.com");
        driver.manage().window().maximize();
    }

    @After
    public void tearDown() throws Exception {
        driver.quit();
    }

    @Test
    public void test() throws InterruptedException {
        //test content
    }
}