In some scenarios, you may want to set the focus of your commands to a particular Java type. For instance, you may want the Roo shell to execute field commands on a particular Java type, so that you don't need to specify the class argument in your field commands.
Start the Roo shell from the C:\roo-cookbook\ch01-recipe directory, which contains the flight-app Roo project.
Spring Roo provides a focus command, which lets you change the target of your commands to a different Java type. The following sequence of steps shows how we can use the focus command to switch from one type to another:
Execute the following
focuscommand to specify that you want to work with theflight-appproject. This will change the Roo prompt to reflect the top-level package name of Roo project:roo> focus --class ~Create
FlightDescclass using theclasscommand. Use~to denote that you are specifying the package name for the class with respect to the top-level package of the project. This will change the Roo prompt to refer to theFlightDesctype, shown as follows:sample.roo.Flightapp roo> class --class ~.domain.FlightDesc --rooAnnotations Created SRC_MAIN_JAVA\sample\roo\flightapp\domain\FlightDesc.java
Create a
Flightclass using theclasscommand. This will change the Roo prompt fromFlightDesctype to refer to the newly createdFlighttype, as shown here:~.domain.FlightDesc roo> class --class ~.domain.Flight --rooAnnotations Created SRC_MAIN_JAVA\sample\roo\flightapp\domain\Flight.java
Use a
focuscommand to switch to theFlightDesctype. This will change the Roo prompt from referring toFlighttype toFlightDesctype, as shown here:~.domain.Flight roo> focus --class ~.domain.FlightDescAdd
from_cityandto_cityattributes to theFlightDescclass as shown here. As the currently referred type by Roo prompt isFlightDesc, you don't need to specify theclassargument:~.domain.FlightDesc roo> field string from_city ~.domain.FlightDesc roo> field string to_city
Without changing focus to the
Flightclass, add aflight_Idattribute to theFlightclass by using thefieldcommand along with theclassargument, as shown here. Theclassargument specifies that the target of the command is theFlightclass and not the currently referredFlightDescclass:~.domain.FlightDesc roo> field number --fieldName flight_Id --type java.lang.Integer --class ~.domain.Flight
The class argument of the focus command lets you specify the fully-qualified name of the Java type with which you want to work. The ~ symbol is used to indicate the top-level package of the Roo project that you specified during creation of the Roo project.
The use of the focus command is mainly to simplify writing commands targeting a particular Java type. If you don't want to use the focus command in a situation, then you can always use the class argument of the command to specify the target Java type of the command.