How to verify element present or visible in selenium 2 (Selenium WebDriver)

Verify Element Present or Visible in Web Application Check

1.ispresent

2.isvisible

3.isenable

4.textpresent

in Selenium WebDrvier using Java

To check Element Present:

if(driver.findElements(By.xpath("value")).size() != 0){
System.out.println("Element is Present");
}else{
System.out.println("Element is Absent");
}

                  OR
if(driver.findElement(By.xpath("value"))!= null){
System.out.println("Element is Present");
}else{
System.out.println("Element is Absent");
}

To check Visible:

if( driver.findElement(By.cssSelector("a > font")).isDisplayed()){
System.out.println("Element is Visible");
}else{
System.out.println("Element is InVisible");
}

To check Enable:

if( driver.findElement(By.cssSelector("a > font")).isEnabled()){
System.out.println("Element is Enable");
}else{
System.out.println("Element is Disabled");
}

To check text present:

if(driver.getPageSource().contains("Text to check")){
System.out.println("Text is present");
}else{
System.out.println("Text is absent");
}