代码如下：

package appinumdemo.apps;


import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.*;
import org.openqa.selenium.interactions.HasTouchScreen;
import org.openqa.selenium.interactions.TouchScreen;
import org.openqa.selenium.remote.CapabilityType;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.remote.RemoteTouchScreen;
import org.openqa.selenium.remote.RemoteWebDriver;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;

import java.io.File;
import java.net.URL;
import java.util.List;

public class Test1{
    private WebDriver driver;

    @Before
    public void setUp() throws Exception {
        // set up appium
        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability("device","selendroid");
//------------------------------------下面的不知如何写--------------------------------------------------------------//
        //capabilities.setCapability("app", "/system/app/Browser.apk");
        //capabilities.setCapability("app", app.getAbsolutePath());
        //capabilities.setCapability("app-package", "com.android.browser");
        //capabilities.setCapability("app-activity", ".FMSActivity");
//----------------------------------------------------------------------------------------------------------------------------//
        driver = new SwipeableWebDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);
    }


    @Test
    public void testcase_001() throws Exception{
        driver.get("http://www.baidu.com");
        WebDriverWait wait = new WebDriverWait(driver, 30);
        wait.until(ExpectedConditions.presenceOfElementLocated(By.name("wd")));
        WebElement keyword = driver.findElement(By.name("wd"));
        keyword.sendKeys("appium");
        driver.findElement(By.id("su1")).click();
        Thread.sleep(5000);
     }

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

    public class SwipeableWebDriver extends RemoteWebDriver implements HasTouchScreen {
        private RemoteTouchScreen touch;
        public SwipeableWebDriver(URL remoteAddress, Capabilities desiredCapabilities) {
            super(remoteAddress, desiredCapabilities);
            touch = new RemoteTouchScreen(getExecuteMethod());
        }
        public TouchScreen getTouch() {
            return touch;
        }
    }

}

driver = new SwipeableWebDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);

报空指针，跟到方法里 super(remoteAddress, desiredCapabilities) 运行不过去，遇到过请帮助一下，谢了