Velocity string function

问题:

I just start using Java Velocity. Now I want to create a java class template.

package $app.package_namespace
public class ${app.name}Station

{
    #foreach($s_attribute in $app.station)
         $s_attribute.type $s_attribute.name,
    #end
    public $app.name Station(#foreach($s_attribute in $app.station)
                                 $s_attribute.type $s_attribute.name;
                             #end)
{
    #foreach($s_attribute in $app.station)
          $s_attribute.name=$s_attribute.name;
    #end
}
#foreach($s_attribute in $app.station)
    public ${s_attribute.type} get${s_attribute.name}()
    {
        return  get${s_attribute.name}();
    }
#end
}

The problem is s_attribute.name first character is lowercase. When I create getter and setter function for attributes. I need change first character to uppercase.

Did anyone know how to do it?

回答1:

You can invoke standard java methods on these objects. If s_attribute.name is type String you can directly use $s_attribute.name.toUpperCase() or for your specific case use $s_attribute.name.substring(0,1).toUpperCase() and $s_attribute.name.substring(1).toLowerCase()

回答2:

There is capitalize() method in DisplayTool:

get${display.capitalize($s_attribute.name)}()

回答3:

If you are using commons-lang you can use the StringUtils class:

context.put("StringUtils", org.apache.commons.lang3.StringUtils.class);

Then in your template:

...
return  get$StringUtils.capitalize(s_attribute.name)();
...

回答4:

You could just create 2 methods getName() and getname() then when you use ${s_attribute.name} velocity will use getname() and when you use ${s_attribute.Name} velocity will use the getName() method.

From the Velocity guide:

Property Lookup Rules

As was mentioned earlier, properties often refer to methods of the parent object. Velocity is quite clever when figuring out which method corresponds to a requested property. It tries out different alternatives based on several established naming conventions. The exact lookup sequence depends on whether or not the property name starts with an upper-case letter. For lower-case names, such as $customer.address, the sequence is

getaddress()
getAddress()
get("address")
isAddress()

For upper-case property names like $customer.Address, it is slightly different:

getAddress()
getaddress()
get("Address")
isAddress()

What i'm suggesting is that you handle it in your object on the backend.