third_codes/mapstruct
1
0
Fork 0
mirror of https://github.com/mapstruct/mapstruct.git synced 2025-07-12 00:00:08 +08:00
Code Issues Packages Projects Releases Wiki Activity

Updating readme file

Browse Source
This commit is contained in:
Gunnar Morling 2013-04-07 17:07:56 +03:00
parent 4fb2220017
commit 19c9c98728
1 changed files with 23 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
readme.md
View File

@ -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.
## 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):
@ -64,36 +64,32 @@ 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
public String from(Integer source) {
return source != null ? source.toString() : null;
}
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:
@Override
public Integer to(String target) {
return target != null ? Integer.valueOf( target ) : null;
}
}
```java
@Mapper
public interface CarMapper {
To make use of a converter, specify its type within the `@Mapping` annotation:
CarMapper INSTANCE = Mappers.getMapper( CarMapper.class );
@Mapper
public interface CarMapper {
@Mapping(source = "numberOfSeats", target = "seatCount")
CarDto carToCarDto(Car car);
CarMapper INSTANCE = Mappers.getMapper( CarMapper.class );
Car carDtoToCar(CarDto carDto); (1)
}
```
@Mappings({
@Mapping(source = "numberOfSeats", target = "seatCount"),
@Mapping(source = "yearOfManufacture", target = "manufacturingYear", converter = IntToStringConverter.class)
})
CarDto carToCarDto(Car car);
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.
Car carDtoToCar(CarDto carDto);
}
## Mapping referenced objects and collections
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
# Using MapStruct
@ -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>
</properties>
<!-- ... -->
...
<dependencies>
<dependency>
<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>
</dependency>
</dependencies>
<!-- ... -->
...
<build>
<plugins>
<plugin>