Generics Issue

AbstractEntity.java

package tld.examples.builders;

public abstract class AbstractEntity {

    protected String varAbstractEntity;

    public AbstractEntity() {
    }

    public AbstractEntity(final AbstractEntityBuilder abstractEntityBuilder) {
        this.varAbstractEntity = abstractEntityBuilder.entity.varAbstractEntity;
    }

    public String getVarAbstractEntity() {
        return this.varAbstractEntity;
    }

    public static class AbstractEntityBuilder<
            B extends AbstractEntityBuilder,
            E extends AbstractEntity> {

        protected final E entity;

        public AbstractEntityBuilder(final E abstractEntity) {
            this.entity = abstractEntity;
        }

        public B withVarAbstractEntity(final String varAbstractEntity) {
            this.entity.varAbstractEntity = varAbstractEntity;
            return (B) this;
        }

    }

}

AbstractMiddleEntity.java

package tld.examples.builders;

public abstract class AbstractMiddleEntity
        extends AbstractEntity {

    protected String varAbstractMiddleEntity;

    public AbstractMiddleEntity() {
        super();
    }

    public AbstractMiddleEntity(final AbstractMiddleEntityBuilder abstractMiddleEntityBuilder) {
        super(abstractMiddleEntityBuilder);
//        this.varAbstractMiddleEntity = abstractMiddleEntityBuilder.entity.varAbstractMiddleEntity; // why won't this line see varAbstractMiddleEntity
    }

    public String getVarAbstractMiddleEntity() {
        return this.varAbstractMiddleEntity;
    }

    public static class AbstractMiddleEntityBuilder<
            B extends AbstractMiddleEntityBuilder,
            E extends AbstractMiddleEntity>
            extends AbstractEntityBuilder<B, E> {

        public AbstractMiddleEntityBuilder(final E abstractEntity) {
            super(abstractEntity);
        }

        public B withVarAbstractMiddleEntity(final String varAbstractMiddleEntity) {
            this.entity.varAbstractMiddleEntity = varAbstractMiddleEntity;
            return (B) this;
        }

    }

}

AlphaEntity.java

package tld.examples.builders;

public class AlphaEntity
        extends AbstractEntity {

    private String varAlphaEntityPre;
    private String varAlphaEntityPost;

    private AlphaEntity() {
        super();
    }

    public AlphaEntity(final AlphaEntityBuilder alphaEntityBuilder) {
        super(alphaEntityBuilder);
        this.varAlphaEntityPre = alphaEntityBuilder.entity.varAlphaEntityPre;
        this.varAlphaEntityPost = alphaEntityBuilder.entity.varAlphaEntityPost;
    }

    public String getVarAlphaEntityPre() {
        return this.varAlphaEntityPre;
    }

    public String getVarAlphaEntityPost() {
        return this.varAlphaEntityPost;
    }

    public static class AlphaEntityBuilder
            extends AbstractEntityBuilder<AlphaEntityBuilder, AlphaEntity> {

        public AlphaEntityBuilder() {
            super(new AlphaEntity());
        }

        public AlphaEntityBuilder withVarAlphaEntityPre(final String varAlphaEntityPre) {
            this.entity.varAlphaEntityPre = varAlphaEntityPre;
            return this;
        }

        public AlphaEntityBuilder withVarAlphaEntityPost(final String varAlphaEntityPost) {
            this.entity.varAlphaEntityPost = varAlphaEntityPost;
            return this;
        }

        public AlphaEntity build() {
            return new AlphaEntity(this);
        }

    }

}

AlphaEntityTest.java

package tld.examples.builders;

public class AlphaEntityTest {

    public static void main(final String[] args) {
        testAlphaEntity();
    }

    public static void testAlphaEntity() {

        System.out.println("Alpha Post");

        final AlphaEntity.AlphaEntityBuilder alphaEntityBuilder = new AlphaEntity.AlphaEntityBuilder()
                .withVarAlphaEntityPre("Alpha.AlphaEntityPre")
                .withVarAbstractEntity("Alpha.AbstractEntity")
                .withVarAlphaEntityPost("Alpha.AlphaEntityPost");

        final AlphaEntity alphaEntity = alphaEntityBuilder.build();

        System.out.println(alphaEntity.getVarAbstractEntity());
        System.out.println(alphaEntity.getVarAlphaEntityPre());
        System.out.println(alphaEntity.getVarAlphaEntityPost());

        System.out.println("Alpha Post");
    }

}

BravoEntity.java

package tld.examples.builders;

public class BravoEntity
        extends AbstractMiddleEntity {

    private String varBravoEntityPre;
    private String varBravoEntityPost;

    private BravoEntity() {
        super();
    }

    public BravoEntity(final BravoEntityBuilder bravoEntityBuilder) {
        super(bravoEntityBuilder);
        this.varBravoEntityPre = bravoEntityBuilder.entity.varBravoEntityPre;
        this.varBravoEntityPost = bravoEntityBuilder.entity.varBravoEntityPost;
    }

    public String getVarBravoEntityPre() {
        return this.varBravoEntityPre;
    }

    public String getVarBravoEntityPost() {
        return this.varBravoEntityPost;
    }

    public static class BravoEntityBuilder
            extends AbstractMiddleEntityBuilder<BravoEntityBuilder, BravoEntity> {

        public BravoEntityBuilder() {
            super(new BravoEntity());
        }

        public BravoEntityBuilder withVarBravoEntityPre(final String varBravoEntityPre) {
            this.entity.varBravoEntityPre = varBravoEntityPre;
            return this;
        }

        public BravoEntityBuilder withVarBravoEntityPost(final String varBravoEntityPost) {
            this.entity.varBravoEntityPost = varBravoEntityPost;
            return this;
        }

        public BravoEntity build() {
            return new BravoEntity(this);
        }

    }

}

BravoEntityTest.java

package tld.examples.builders;

public class BravoEntityTest {

    public static void main(final String[] args) {
        testBravoEntity();
    }

    public static void testBravoEntity() {

        System.out.println("Bravo Pre");

        final BravoEntity.BravoEntityBuilder bravoEntityBuilder = new BravoEntity.BravoEntityBuilder()
                .withVarBravoEntityPre("Bravo.BravoEntityPre")
                .withVarAbstractEntity("Bravo.AbstractEntity")
                .withVarBravoEntityPost("Bravo.BravoEntityPost")
                .withVarAbstractMiddleEntity("Alpha.AbstractMiddleEntity");

        final BravoEntity bravoEntity = bravoEntityBuilder.build();

        System.out.println(bravoEntity.getVarAbstractEntity());
        System.out.println(bravoEntity.getVarAbstractMiddleEntity());
        System.out.println(bravoEntity.getVarBravoEntityPre());
        System.out.println(bravoEntity.getVarBravoEntityPost());

        System.out.println("Bravo Post");
    }

}