net.bytebuddy.dynamic.scaffold.FieldLocator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of byte-buddy-dep Show documentation
Show all versions of byte-buddy-dep Show documentation
Byte Buddy is a Java library for creating Java classes at run time.
This artifact is a build of Byte Buddy with a remaining dependency onto ASM.
You should never depend on this module without repackaging Byte Buddy and ASM into your own namespace.
package net.bytebuddy.dynamic.scaffold;
import net.bytebuddy.description.field.FieldDescription;
import net.bytebuddy.description.field.FieldList;
import net.bytebuddy.description.type.TypeDefinition;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.matcher.ElementMatcher;
import static net.bytebuddy.matcher.ElementMatchers.*;
/**
* A field locator offers an interface for locating a field that is declared by a specified type.
*/
public interface FieldLocator {
/**
* Locates a field with the given name and throws an exception if no such type exists.
*
* @param name The name of the field to locate.
* @return A resolution for a field lookup.
*/
Resolution locate(String name);
/**
* Locates a field with the given name and type and throws an exception if no such type exists.
*
* @param name The name of the field to locate.
* @param type The type fo the field to locate.
* @return A resolution for a field lookup.
*/
Resolution locate(String name, TypeDescription type);
/**
* A resolution for a field lookup.
*/
interface Resolution {
/**
* Returns {@code true} if a field was located.
*
* @return {@code true} if a field was located.
*/
boolean isResolved();
/**
* Returns the field description if a field was located. This method must only be called if
* this resolution was actually resolved.
*
* @return The located field.
*/
FieldDescription getFieldDescription();
/**
* An illegal resolution.
*/
enum Illegal implements Resolution {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public boolean isResolved() {
return false;
}
@Override
public FieldDescription getFieldDescription() {
throw new IllegalStateException("Could not locate field");
}
@Override
public String toString() {
return "FieldLocator.Resolution.Illegal." + name();
}
}
/**
* A simple implementation for a field resolution.
*/
class Simple implements Resolution {
/**
* A description of the located field.
*/
private final FieldDescription fieldDescription;
/**
* Creates a new simple resolution for a field.
*
* @param fieldDescription A description of the located field.
*/
protected Simple(FieldDescription fieldDescription) {
this.fieldDescription = fieldDescription;
}
@Override
public boolean isResolved() {
return true;
}
@Override
public FieldDescription getFieldDescription() {
return fieldDescription;
}
@Override
public boolean equals(Object object) {
if (this == object) return true;
if (object == null || getClass() != object.getClass()) return false;
Simple simple = (Simple) object;
return fieldDescription.equals(simple.fieldDescription);
}
@Override
public int hashCode() {
return fieldDescription.hashCode();
}
@Override
public String toString() {
return "FieldLocator.Resolution.Simple{" +
"fieldDescription=" + fieldDescription +
'}';
}
}
}
/**
* An abstract base implementation of a field locator.
*/
abstract class AbstractBase implements FieldLocator {
/**
* The type accessing the field.
*/
protected final TypeDescription accessingType;
/**
* Creates a new field locator.
*
* @param accessingType The type accessing the field.
*/
protected AbstractBase(TypeDescription accessingType) {
this.accessingType = accessingType;
}
@Override
public Resolution locate(String name) {
FieldList candidates = locate(named(name).and(isVisibleTo(accessingType)));
return candidates.size() == 1
? new Resolution.Simple(candidates.getOnly())
: Resolution.Illegal.INSTANCE;
}
@Override
public Resolution locate(String name, TypeDescription type) {
FieldList candidates = locate(named(name).and(fieldType(type)).and(isVisibleTo(accessingType)));
return candidates.size() == 1
? new Resolution.Simple(candidates.getOnly())
: Resolution.Illegal.INSTANCE;
}
/**
* Locates fields that match the given matcher.
*
* @param matcher The matcher that identifies fields of interest.
* @return A list of fields that match the specified matcher.
*/
protected abstract FieldList locate(ElementMatcher matcher);
@Override
public boolean equals(Object object) {
if (this == object) return true;
if (object == null || getClass() != object.getClass()) return false;
AbstractBase that = (AbstractBase) object;
return accessingType.equals(that.accessingType);
}
@Override
public int hashCode() {
return accessingType.hashCode();
}
}
/**
* A field locator that only looks up fields that are declared by a specific type.
*/
class ForExactType extends AbstractBase {
/**
* The type for which to look up fields.
*/
private final TypeDescription typeDescription;
/**
* Creates a new field locator for locating fields from a declared type.
*
* @param typeDescription The type for which to look up fields that is also providing the accessing type.
*/
public ForExactType(TypeDescription typeDescription) {
this(typeDescription, typeDescription);
}
/**
* Creates a new field locator for locating fields from a declared type.
*
* @param typeDescription The type for which to look up fields.
* @param accessingType The accessing type.
*/
public ForExactType(TypeDescription typeDescription, TypeDescription accessingType) {
super(accessingType);
this.typeDescription = typeDescription;
}
@Override
protected FieldList locate(ElementMatcher matcher) {
return typeDescription.getDeclaredFields().filter(matcher);
}
@Override
public boolean equals(Object object) {
if (this == object) return true;
if (object == null || getClass() != object.getClass()) return false;
if (!super.equals(object)) return false;
ForExactType that = (ForExactType) object;
return typeDescription.equals(that.typeDescription);
}
@Override
public int hashCode() {
int result = super.hashCode();
result = 31 * result + typeDescription.hashCode();
return result;
}
@Override
public String toString() {
return "FieldLocator.ForExactType{" +
"accessingType=" + accessingType +
", typeDescription=" + typeDescription +
'}';
}
}
/**
* A field locator that looks up fields that are declared within a class's class hierarchy.
*/
class ForClassHierarchy extends AbstractBase {
/**
* The type for which to look up a field within its class hierarchy.
*/
private final TypeDescription typeDescription;
/**
* Creates a field locator that looks up fields that are declared within a class's class hierarchy.
*
* @param typeDescription The type for which to look up a field within its class hierarchy which is also the accessing type.
*/
public ForClassHierarchy(TypeDescription typeDescription) {
this(typeDescription, typeDescription);
}
/**
* Creates a field locator that looks up fields that are declared within a class's class hierarchy.
*
* @param typeDescription The type for which to look up a field within its class hierarchy.
* @param accessingType The accessing type.
*/
public ForClassHierarchy(TypeDescription typeDescription, TypeDescription accessingType) {
super(accessingType);
this.typeDescription = typeDescription;
}
@Override
protected FieldList locate(ElementMatcher matcher) {
for (TypeDefinition typeDefinition : typeDescription) {
FieldList candidates = typeDefinition.getDeclaredFields().filter(matcher);
if (!candidates.isEmpty()) {
return candidates;
}
}
return new FieldList.Empty();
}
@Override
public boolean equals(Object object) {
if (this == object) return true;
if (object == null || getClass() != object.getClass()) return false;
if (!super.equals(object)) return false;
ForClassHierarchy that = (ForClassHierarchy) object;
return typeDescription.equals(that.typeDescription);
}
@Override
public int hashCode() {
int result = super.hashCode();
result = 31 * result + typeDescription.hashCode();
return result;
}
@Override
public String toString() {
return "FieldLocator.ForClassHierarchy{" +
"accessingType=" + accessingType +
", typeDescription=" + typeDescription +
'}';
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy