package net.bytebuddy;
import lombok.EqualsAndHashCode;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.utility.RandomString;
/**
* <p>
* A naming strategy for determining a fully qualified name for a dynamically created Java type.
* </p>
* <p>
* Note that subclasses that lie within the same package as their superclass can access package-private methods
* of super types within the same package.
* </p>
*/
public interface NamingStrategy {
/**
* Determines a new name when creating a new type that subclasses the provided type.
*
* @param superClass The super type of the created type.
* @return The name of the dynamic type.
*/
String subclass(TypeDescription.Generic superClass);
/**
* Determines a name for the dynamic type when redefining the provided type.
*
* @param typeDescription The type being redefined.
* @return The name of the dynamic type.
*/
String redefine(TypeDescription typeDescription);
/**
* Determines a name for the dynamic type when rebasing the provided type.
*
* @param typeDescription The type being redefined.
* @return The name of the dynamic type.
*/
String rebase(TypeDescription typeDescription);
/**
* An abstract base implementation where the names of redefined and rebased types are retained.
*/
abstract class AbstractBase implements NamingStrategy {
@Override
public String subclass(TypeDescription.Generic superClass) {
return name(superClass.asErasure());
}
/**
* Determines a new name when creating a new type that subclasses the provided type.
*
* @param superClass The super type of the created type.
* @return The name of the dynamic type.
*/
protected abstract String name(TypeDescription superClass);
@Override
public String redefine(TypeDescription typeDescription) {
return typeDescription.getName();
}
@Override
public String rebase(TypeDescription typeDescription) {
return typeDescription.getName();
}
}
/**
* A naming strategy that creates a name by concatenating:
* <ol>
* <li>The super classes package and name</li>
* <li>A given suffix string</li>
* <li>A random number</li>
* </ol>
* Between all these elements, a {@code $} sign is included into the name to improve readability. As an exception,
* types that subclass classes from the {@code java.**} packages are prefixed with a given package. This is
* necessary as it is illegal to define non-bootstrap classes in this name space. The same strategy is applied
* when subclassing a signed type which is equally illegal.
*/
@EqualsAndHashCode(callSuper = false, exclude = "randomString")
class SuffixingRandom extends AbstractBase {
/**
* The default package for defining types that are renamed to not be contained in the
* {@link net.bytebuddy.NamingStrategy.SuffixingRandom#JAVA_PACKAGE} package.
*/
public static final String BYTE_BUDDY_RENAME_PACKAGE = "net.bytebuddy.renamed";
/**
* Indicates that types of the {@code java.*} package should not be prefixed.
*/
public static final String NO_PREFIX = "";
/**
* The package prefix of the {@code java.*} packages for which the definition of
* non-bootstrap types is illegal.
*/
private static final String JAVA_PACKAGE = "java.";
/**
* The suffix to attach to a super type name.
*/
private final String suffix;
/**
* The renaming location for types of the {@link net.bytebuddy.NamingStrategy.SuffixingRandom#JAVA_PACKAGE}.
*/
private final String javaLangPackagePrefix;
/**
* An instance for creating random seed values.
*/
private final RandomString randomString;
/**
* A resolver for the base name for naming the unnamed type.
*/
private final BaseNameResolver baseNameResolver;
/**
* Creates an immutable naming strategy with a given suffix but moves types that subclass types within
* the {@code java.lang} package into Byte Buddy's package namespace. All names are derived from the
* unnamed type's super type.
*
* @param suffix The suffix for the generated class.
*/
public SuffixingRandom(String suffix) {
this(suffix, BaseNameResolver.ForUnnamedType.INSTANCE);
}
/**
* Creates an immutable naming strategy with a given suffix but moves types that subclass types within
* the {@code java.lang} package into Byte Buddy's package namespace.
*
* @param suffix The suffix for the generated class.
* @param javaLangPackagePrefix The fallback namespace for type's that subclass types within the
* {@code java.*} namespace. If The prefix is set to the empty string,
* no prefix is added.
*/
public SuffixingRandom(String suffix, String javaLangPackagePrefix) {
this(suffix, BaseNameResolver.ForUnnamedType.INSTANCE, javaLangPackagePrefix);
}
/**
* Creates an immutable naming strategy with a given suffix but moves types that subclass types within
* the {@code java.lang} package into Byte Buddy's package namespace.
*
* @param suffix The suffix for the generated class.
* @param baseNameResolver The base name resolver that is queried for locating the base name.
*/
public SuffixingRandom(String suffix, BaseNameResolver baseNameResolver) {
this(suffix, baseNameResolver, BYTE_BUDDY_RENAME_PACKAGE);
}
/**
* Creates an immutable naming strategy with a given suffix but moves types that subclass types within
* the {@code java.lang} package into a given namespace.
*
* @param suffix The suffix for the generated class.
* @param baseNameResolver The base name resolver that is queried for locating the base name.
* @param javaLangPackagePrefix The fallback namespace for type's that subclass types within the
* {@code java.*} namespace. If The prefix is set to the empty string,
* no prefix is added.
*/
public SuffixingRandom(String suffix, BaseNameResolver baseNameResolver, String javaLangPackagePrefix) {
this.suffix = suffix;
this.baseNameResolver = baseNameResolver;
this.javaLangPackagePrefix = javaLangPackagePrefix;
randomString = new RandomString();
}
@Override
protected String name(TypeDescription superClass) {
String baseName = baseNameResolver.resolve(superClass);
if (baseName.startsWith(JAVA_PACKAGE) && !javaLangPackagePrefix.equals("")) {
baseName = javaLangPackagePrefix + "." + baseName;
}
return String.format("%s$%s$%s", baseName, suffix, randomString.nextString());
}
/**
* A base name resolver is responsible for resolving a name onto which the suffix is appended.
*/
public interface BaseNameResolver {
/**
* Resolves the base name for a given type description.
*
* @param typeDescription The type for which the base name is resolved.
* @return The base name for the given type.
*/
String resolve(TypeDescription typeDescription);
/**
* Uses the unnamed type's super type's name as the resolved name.
*/
enum ForUnnamedType implements BaseNameResolver {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public String resolve(TypeDescription typeDescription) {
return typeDescription.getName();
}
}
/**
* Uses a specific type's name as the resolved name.
*/
@EqualsAndHashCode
class ForGivenType implements BaseNameResolver {
/**
* The type description which represents the resolved name.
*/
private final TypeDescription typeDescription;
/**
* Creates a new base name resolver that resolves a using the name of a given type.
*
* @param typeDescription The type description which represents the resolved name.
*/
public ForGivenType(TypeDescription typeDescription) {
this.typeDescription = typeDescription;
}
@Override
public String resolve(TypeDescription typeDescription) {
return this.typeDescription.getName();
}
}
/**
* A base name resolver that simply returns a fixed value.
*/
@EqualsAndHashCode
class ForFixedValue implements BaseNameResolver {
/**
* The fixed base name.
*/
private final String name;
/**
* Creates a new base name resolver for a fixed name.
*
* @param name The fixed name
*/
public ForFixedValue(String name) {
this.name = name;
}
@Override
public String resolve(TypeDescription typeDescription) {
return name;
}
}
}
}
/**
* A naming strategy that creates a name by prefixing a given class and its package with another package and
* by appending a random number to the class's simple name.
*/
@EqualsAndHashCode(callSuper = false, of = "prefix")
class PrefixingRandom extends AbstractBase {
/**
* The package to prefix.
*/
private final String prefix;
/**
* A seed generator.
*/
private final RandomString randomString;
/**
* Creates a new prefixing random naming strategy.
*
* @param prefix The prefix to append.
*/
public PrefixingRandom(String prefix) {
this.prefix = prefix;
randomString = new RandomString();
}
@Override
protected String name(TypeDescription superClass) {
return String.format("%s.%s$%s", prefix, superClass.getName(), randomString.nextString());
}
}
}