org.mapstruct.ap.spi

Class DefaultBuilderProvider

java.lang.Object

org.mapstruct.ap.spi.DefaultBuilderProvider

All Implemented Interfaces:

BuilderProvider

Direct Known Subclasses:

ImmutablesBuilderProvider

public class DefaultBuilderProvider
extends Object
implements BuilderProvider

Default implementation of BuilderProvider. The default builder provider considers all public static parameterless methods of a TypeMirror as potential builder creation methods. For each potential builder creation method checks in the return type of the method if there exists a method that returns the initial TypeMirror if such a combination is found the BuilderInfo is created with those 2 methods. Example:

 public class Person {

     private final String firstName;
     private final String lastName;

     private Person(String firstName, String lastName) {
         this.firstName = firstName;
         this.lastName = lastName;
     }

     //getters

     public static Builder builder() {
         return new Builder();
     }

     public static class Builder {

         private String firstName;
         private String lastName;

         private Builder() {}

         //fluent setters

         public Person create() {
             return new Person( firstName, lastName );
         }
     }
 }
 

In the example above, when searching for a builder for the Person type. The Person#builder method would be a builder creation candidate. Then the return type of Person#builder, Builder, is investigated for a parameterless method that returns Person. When Builder#create is found the BuilderInfo is created with the Person#builder as a builder creation method and Builder#create as a build method.

IMPORTANT: Types from the java and javax packages are excluded from inspection

Author:

Filip Hrisafov

Field Summary

Fields

Modifier and Type	Field and Description
protected Elements	elementUtils
protected Types	typeUtils

Constructor Summary

Constructors

Constructor and Description
DefaultBuilderProvider()

Method Summary

Modifier and Type	Method and Description
protected BuilderInfo	findBuilderInfo(TypeElement typeElement) Find the BuilderInfo for the given typeElement.
BuilderInfo	findBuilderInfo(TypeMirror type) Find the builder information, if any, for the type.
protected Collection<ExecutableElement>	findBuildMethods(TypeElement builderElement, TypeElement typeElement) Searches for a build method for typeElement within the builderElement.
protected TypeElement	getTypeElement(TypeMirror type) Find the TypeElement for the given TypeMirror.
void	init(MapStructProcessingEnvironment processingEnvironment) Initializes the builder provider with the MapStruct processing environment.
protected boolean	isBuildMethod(ExecutableElement buildMethod, TypeElement typeElement) Checks if the buildMethod is a method that creates typeElement.
protected boolean	isPossibleBuilderCreationMethod(ExecutableElement method, TypeElement typeElement) Checks if the method is a possible builder creation method.
protected boolean	shouldIgnore(TypeElement typeElement) Whether the typeElement should be ignored, i.e.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

elementUtils

protected Elements elementUtils

typeUtils

protected Types typeUtils

Constructor Detail

DefaultBuilderProvider

public DefaultBuilderProvider()

Method Detail

init

public void init(MapStructProcessingEnvironment processingEnvironment)

Description copied from interface: BuilderProvider

Initializes the builder provider with the MapStruct processing environment.

Specified by:

init in interface BuilderProvider

Parameters:

processingEnvironment - environment for facilities

findBuilderInfo

public BuilderInfo findBuilderInfo(TypeMirror type)

Description copied from interface: BuilderProvider

Find the builder information, if any, for the type.

Specified by:

findBuilderInfo in interface BuilderProvider

Parameters:

type - the type for which a builder should be found

Returns:

the builder info for the type if it exists, or null if there is no builder

getTypeElement

protected TypeElement getTypeElement(TypeMirror type)

Find the TypeElement for the given TypeMirror.

Parameters:

type - for which the TypeElement needs to be found/

Returns:

the type element or null if the TypeMirror is not a DeclaredType and the declared type element is not TypeElement

Throws:

TypeHierarchyErroneousException - if the TypeMirror is of kind TypeKind.ERROR

findBuilderInfo

protected BuilderInfo findBuilderInfo(TypeElement typeElement)

Find the BuilderInfo for the given typeElement.

The default implementation iterates over all the methods in typeElement and uses isPossibleBuilderCreationMethod(ExecutableElement, TypeElement) and findBuildMethods(TypeElement, TypeElement) to create the BuilderInfo.

The default implementation uses shouldIgnore(TypeElement) to check if the typeElement should be ignored.

In case there are multiple BuilderInfo then a MoreThanOneBuilderCreationMethodException is thrown.

Parameters:

typeElement - the type element for which a builder searched

Returns:

the BuilderInfo or null if no builder was found for the type findBuildMethods(TypeElement, TypeElement)

Throws:

MoreThanOneBuilderCreationMethodException - if there are multiple builder creation methods

isPossibleBuilderCreationMethod

protected boolean isPossibleBuilderCreationMethod(ExecutableElement method,
                                                  TypeElement typeElement)

Checks if the method is a possible builder creation method.

The default implementation considers a method as a possible creation method if the following is satisfied:

• The method has no parameters
• It is a public static method
• The return type of the method is not the same as the typeElement

Parameters:

method - The method that needs to be checked

typeElement - the enclosing element of the method, i.e. the type in which the method is located in

Returns:

true if the method is a possible builder creation method, false otherwise

findBuildMethods

protected Collection<ExecutableElement> findBuildMethods(TypeElement builderElement,
                                                         TypeElement typeElement)

Searches for a build method for typeElement within the builderElement.

The default implementation iterates over each method in builderElement and uses isBuildMethod(ExecutableElement, TypeElement) to check if the method is a build method for typeElement.

The default implementation uses shouldIgnore(TypeElement) to check if the builderElement should be ignored, i.e. not checked for build elements.

If there are multiple methods that satisfy isBuildMethod(ExecutableElement, TypeElement) and one of those methods is names build that that method would be considered as a build method.

Parameters:

builderElement - the element for the builder

typeElement - the element for the type that is being built

Returns:

the build method for the typeElement if it exists, or null if it does not build

isBuildMethod

protected boolean isBuildMethod(ExecutableElement buildMethod,
                                TypeElement typeElement)

Checks if the buildMethod is a method that creates typeElement.

The default implementation considers a method to be a build method if the following is satisfied:

• The method has no parameters
• The method is public
• The return type of method is assignable to the typeElement

Parameters:

buildMethod - the method that should be checked

typeElement - the type element that needs to be built

Returns:

true if the buildMethod is a build method for typeElement, false otherwise

shouldIgnore

protected boolean shouldIgnore(TypeElement typeElement)

Whether the typeElement should be ignored, i.e. not used in inspection.

The default implementations ignores null elements and elements that belong to the java and javax packages

Parameters:

typeElement - that needs to be checked

Returns:

true if the element should be ignored, false otherwise