运行后出现这样的提示,怎么解决
Exception in thread "main" org.openqa.selenium.WebDriverException: Cannot find firefox binary in PATH. Make sure firefox is installed. OS appears to be: VISTA
Build info: version: '3.4.0', revision: 'unknown', time: 'unknown'
System info: host: 'LU', ip: '192.168.219.1', os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.8.0_31'
Driver info: driver.version: FirefoxDriver
at org.openqa.selenium.firefox.internal.Executable.<init>(Executable.java:75)
at org.openqa.selenium.firefox.FirefoxBinary.<init>(FirefoxBinary.java:60)
at org.openqa.selenium.firefox.FirefoxBinary.<init>(FirefoxBinary.java:56)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:127)
at openliu.main(openliu.java:9)