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Updating readme file

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Gunnar Morling 2013-04-07 17:07:56 +03:00
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@ -4,7 +4,7 @@ MapStruct is a Java [annotation processor](http://docs.oracle.com/javase/6/docs/
All you have to do is to define a mapper interfaces, annotate it with the `@Mapper` annotation and add the required mapping methods. During compilation, MapStruct will generate an implementation for the mapper interface. This implementation uses plain Java method invocations, i.e. no reflection or similar. All you have to do is to define a mapper interfaces, annotate it with the `@Mapper` annotation and add the required mapping methods. During compilation, MapStruct will generate an implementation for the mapper interface. This implementation uses plain Java method invocations, i.e. no reflection or similar.
## Hello World # Hello World
The following shows a simple example for using MapStruct. First, let's define an object (e.g. a JPA entity) and an accompanying data transfer object (DTO): The following shows a simple example for using MapStruct. First, let's define an object (e.g. a JPA entity) and an accompanying data transfer object (DTO):
@ -64,37 +64,33 @@ public void shouldMapCarToDto() {
} }
``` ```
Sometimes not only the names of two corresponding attributes differ, but also their types. This can be addressed by defining a custom type converter: # Advanced mappings
public class IntToStringConverter implements Converter<Integer, String> { ## Reverse mappings
@Override Often bi-directional mappings are required, e.g. from entity to DTO and from DTO to entity. For this purpose, simply declare a method with the required parameter and return type on the mapping interface which also declares the forward mapping method:
public String from(Integer source) {
return source != null ? source.toString() : null;
}
@Override ```java
public Integer to(String target) { @Mapper
return target != null ? Integer.valueOf( target ) : null; public interface CarMapper {
}
}
To make use of a converter, specify its type within the `@Mapping` annotation:
@Mapper CarMapper INSTANCE = Mappers.getMapper( CarMapper.class );
public interface CarMapper {
CarMapper INSTANCE = Mappers.getMapper( CarMapper.class ); @Mapping(source = "numberOfSeats", target = "seatCount")
CarDto carToCarDto(Car car);
Car carDtoToCar(CarDto carDto); (1)
}
```
@Mappings({ 1. The `carDtoToCar()` method is the reverse mapping method for `carToCarDto()`. Note that the attribute mappings only have to be specified at one of the two methods and will be applied to the corresponding reverse mapping method as well.
@Mapping(source = "numberOfSeats", target = "seatCount"),
@Mapping(source = "yearOfManufacture", target = "manufacturingYear", converter = IntToStringConverter.class) ## Mapping referenced objects and collections
})
CarDto carToCarDto(Car car); Typically an object has not only primitive attributes but also references other objects. E.g. the `Car` class could contain a reference to a `Driver` object, while the `CarDto` class references a `DriverDto` object.
TODO
Car carDtoToCar(CarDto carDto);
}
# Using MapStruct # Using MapStruct
MapStruct is a Java annotation processor based on [JSR 269](jcp.org/en/jsr/detail?id=269) and as such can be used within command line builds (javac, Ant, Maven etc.) as well as from within your IDE. MapStruct is a Java annotation processor based on [JSR 269](jcp.org/en/jsr/detail?id=269) and as such can be used within command line builds (javac, Ant, Maven etc.) as well as from within your IDE.
@ -107,9 +103,7 @@ For Maven based projects add the following to your POM file in order to use MapS
<org.mapstruct.version>[current MapStruct version]</org.mapstruct.version> <org.mapstruct.version>[current MapStruct version]</org.mapstruct.version>
</properties> </properties>
...
<!-- ... -->
<dependencies> <dependencies>
<dependency> <dependency>
<groupId>org.mapstruct</groupId> <groupId>org.mapstruct</groupId>
@ -117,9 +111,7 @@ For Maven based projects add the following to your POM file in order to use MapS
<version>${org.mapstruct.version}</version> <version>${org.mapstruct.version}</version>
</dependency> </dependency>
</dependencies> </dependencies>
...
<!-- ... -->
<build> <build>
<plugins> <plugins>
<plugin> <plugin>