Package org.apache.commons.io.build
Class AbstractSupplier<T,B extends AbstractSupplier<T,B>>
java.lang.Object
org.apache.commons.io.build.AbstractSupplier<T,B>
- Type Parameters:
T- the type of instances to build.B- the type of builder subclass.
- All Implemented Interfaces:
IOSupplier<T>
- Direct Known Subclasses:
AbstractOrigin,AbstractOriginSupplier,SimplePathVisitor.AbstractBuilder,WildcardFileFilter.Builder
public abstract class AbstractSupplier<T,B extends AbstractSupplier<T,B>>
extends Object
implements IOSupplier<T>
Abstracts supplying an instance of
T.
Extend this class to implement the builder pattern.
For example, here is a builder, a domain class, and a test.
The builder:
/**
* Builds Foo instances.
*/
public static class Builder extends AbstractSupplier<Foo, Builder> {
private String bar1;
private String bar2;
private String bar3;
/**
* Builds a new Foo.
*/
@Override
public Foo get() {
return new Foo(bar1, bar2, bar3);
}
public Builder setBar1(final String bar1) {
this.bar1 = bar1;
return this;
}
public Builder setBar2(final String bar2) {
this.bar2 = bar2;
return this;
}
public Builder setBar3(final String bar3) {
this.bar3 = bar3;
return this;
}
}
The domain class:
/**
* Domain class.
*/
public class Foo {
public static Builder builder() {
return new Builder();
}
private final String bar1;
private final String bar2;
private final String bar3;
private Foo(final String bar1, final String bar2, final String bar3) {
this.bar1 = bar1;
this.bar2 = bar2;
this.bar3 = bar3;
}
public String getBar1() {
return bar1;
}
public String getBar2() {
return bar2;
}
public String getBar3() {
return bar3;
}
}
The test:
@Test
public void test() {
final Foo foo = Foo.builder()
.setBar1("value1")
.setBar2("value2")
.setBar3("value3")
.get();
assertEquals("value1", foo.getBar1());
assertEquals("value2", foo.getBar2());
assertEquals("value3", foo.getBar3());
}
- Since:
- 2.12.0
-
Constructor Details
-
AbstractSupplier
public AbstractSupplier()Constructs a new instance for subclasses.
-
-
Method Details
-
asThis
Returns this instance typed as the subclass typeB.This is the same as the expression:
(B) this
- Returns:
- this instance typed as the subclass type
B.
-