Java tutorial
/* * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.facebook.presto.byteCode; import com.google.common.base.Joiner; import com.google.common.base.Preconditions; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableSet; import org.objectweb.asm.ClassVisitor; import javax.annotation.concurrent.NotThreadSafe; import java.util.ArrayList; import java.util.EnumSet; import java.util.List; import java.util.Set; import static com.facebook.presto.byteCode.Access.STATIC; import static com.facebook.presto.byteCode.Access.a; import static com.facebook.presto.byteCode.Access.toAccessModifier; import static com.google.common.collect.Iterables.any; import static com.google.common.collect.Iterables.concat; import static org.objectweb.asm.Opcodes.ACC_SUPER; import static org.objectweb.asm.Opcodes.V1_7; @NotThreadSafe public class ClassDefinition { private final EnumSet<Access> access; private final ParameterizedType type; private final ParameterizedType superClass; private final List<ParameterizedType> interfaces = new ArrayList<>(); private final List<AnnotationDefinition> annotations = new ArrayList<>(); private final List<FieldDefinition> fields = new ArrayList<>(); private final List<MethodDefinition> methods = new ArrayList<>(); private final MethodDefinition classInitializer; private String source; private String debug; public ClassDefinition(EnumSet<Access> access, String name, ParameterizedType superClass, ParameterizedType... interfaces) { this(new CompilerContext(), access, new ParameterizedType(name), superClass, interfaces); } public ClassDefinition(CompilerContext compilerContext, EnumSet<Access> access, String name, ParameterizedType superClass, ParameterizedType... interfaces) { this(compilerContext, access, new ParameterizedType(name), superClass, interfaces); } public ClassDefinition(EnumSet<Access> access, ParameterizedType type, ParameterizedType superClass, ParameterizedType... interfaces) { this(new CompilerContext(), access, type, superClass, interfaces); } public ClassDefinition(CompilerContext compilerContext, EnumSet<Access> access, ParameterizedType type, ParameterizedType superClass, ParameterizedType... interfaces) { Preconditions.checkNotNull(access, "access is null"); Preconditions.checkNotNull(access, "access is null"); Preconditions.checkNotNull(superClass, "superClass is null"); Preconditions.checkNotNull(interfaces, "interfaces is null"); this.access = access; this.type = type; this.superClass = superClass; this.interfaces.addAll(ImmutableList.copyOf(interfaces)); classInitializer = new MethodDefinition(compilerContext, this, a(STATIC), "<clinit>", ParameterizedType.type(void.class), ImmutableList.<NamedParameterDefinition>of()); } public Set<Access> getAccess() { return ImmutableSet.copyOf(access); } public String getName() { return type.getClassName(); } public ParameterizedType getType() { return type; } public ParameterizedType getSuperClass() { return superClass; } public String getSource() { return source; } public List<ParameterizedType> getInterfaces() { return ImmutableList.copyOf(interfaces); } public List<AnnotationDefinition> getAnnotations() { return ImmutableList.copyOf(annotations); } public List<FieldDefinition> getFields() { return ImmutableList.copyOf(fields); } public List<MethodDefinition> getMethods() { return ImmutableList.copyOf(methods); } public void visit(ClassVisitor visitor) { // Generic signature if super class or any interface is generic String signature = null; if (superClass.isGeneric() || any(interfaces, ParameterizedType.isGenericType())) { signature = genericClassSignature(superClass, interfaces); } String[] interfaces = new String[this.interfaces.size()]; for (int i = 0; i < interfaces.length; i++) { interfaces[i] = this.interfaces.get(i).getClassName(); } visitor.visit(V1_7, toAccessModifier(access) | ACC_SUPER, type.getClassName(), signature, superClass.getClassName(), interfaces); // visit source if (source != null) { visitor.visitSource(source, debug); } // visit annotations for (AnnotationDefinition annotation : annotations) { annotation.visitClassAnnotation(visitor); } // visit fields for (FieldDefinition field : fields) { field.visit(visitor); } // visit clinit method classInitializer.visit(visitor, true); // visit methods for (MethodDefinition method : methods) { method.visit(visitor); } // done visitor.visitEnd(); } public AnnotationDefinition declareAnnotation(Class<?> type) { AnnotationDefinition annotationDefinition = new AnnotationDefinition(type); annotations.add(annotationDefinition); return annotationDefinition; } public AnnotationDefinition declareAnnotation(ParameterizedType type) { AnnotationDefinition annotationDefinition = new AnnotationDefinition(type); annotations.add(annotationDefinition); return annotationDefinition; } public FieldDefinition declareField(EnumSet<Access> access, String name, Class<?> type) { FieldDefinition fieldDefinition = new FieldDefinition(this, access, name, type); fields.add(fieldDefinition); return fieldDefinition; } public ClassDefinition addField(EnumSet<Access> access, String name, Class<?> type) { declareField(access, name, type); return this; } public FieldDefinition declareField(EnumSet<Access> access, String name, ParameterizedType type) { FieldDefinition fieldDefinition = new FieldDefinition(this, access, name, type); fields.add(fieldDefinition); return fieldDefinition; } public ClassDefinition addField(EnumSet<Access> access, String name, ParameterizedType type) { declareField(access, name, type); return this; } public ClassDefinition addField(FieldDefinition field) { fields.add(field); return this; } public MethodDefinition getClassInitializer() { return classInitializer; } public MethodDefinition declareConstructor(EnumSet<Access> access, NamedParameterDefinition... parameters) { return declareConstructor(new CompilerContext(), access, parameters); } public MethodDefinition declareConstructor(CompilerContext compilerContext, EnumSet<Access> access, NamedParameterDefinition... parameters) { return declareMethod(compilerContext, access, "<init>", ParameterizedType.type(void.class), ImmutableList.copyOf(parameters)); } public MethodDefinition declareConstructor(CompilerContext compilerContext, EnumSet<Access> access, Iterable<NamedParameterDefinition> parameters) { return declareMethod(compilerContext, access, "<init>", ParameterizedType.type(void.class), ImmutableList.copyOf(parameters)); } public ClassDefinition declareDefaultConstructor(EnumSet<Access> access) { declareConstructor(new CompilerContext(null), access).getBody().pushThis().invokeConstructor(superClass) .ret(); return this; } public ClassDefinition addMethod(MethodDefinition method) { methods.add(method); return this; } public ClassDefinition visitSource(String source, String debug) { this.source = source; this.debug = debug; return this; } public MethodDefinition declareMethod(EnumSet<Access> access, String name, ParameterizedType returnType, NamedParameterDefinition... parameters) { return declareMethod(new CompilerContext(), access, name, returnType, parameters); } public MethodDefinition declareMethod(CompilerContext compilerContext, EnumSet<Access> access, String name, ParameterizedType returnType, NamedParameterDefinition... parameters) { MethodDefinition methodDefinition = new MethodDefinition(compilerContext, this, access, name, returnType, ImmutableList.copyOf(parameters)); methods.add(methodDefinition); return methodDefinition; } public MethodDefinition declareMethod(EnumSet<Access> access, String name, ParameterizedType returnType, Iterable<NamedParameterDefinition> parameters) { return declareMethod(new CompilerContext(), access, name, returnType, parameters); } public MethodDefinition declareMethod(CompilerContext compilerContext, EnumSet<Access> access, String name, ParameterizedType returnType, Iterable<NamedParameterDefinition> parameters) { MethodDefinition methodDefinition = new MethodDefinition(compilerContext, this, access, name, returnType, parameters); methods.add(methodDefinition); return methodDefinition; } public static String genericClassSignature(ParameterizedType classType, ParameterizedType... interfaceTypes) { return Joiner.on("").join(concat(ImmutableList.of(classType), ImmutableList.copyOf(interfaceTypes))); } public static String genericClassSignature(ParameterizedType classType, List<ParameterizedType> interfaceTypes) { return Joiner.on("").join(concat(ImmutableList.of(classType), interfaceTypes)); } @Override public String toString() { final StringBuilder sb = new StringBuilder(); sb.append("ClassDefinition"); sb.append("{access=").append(access); sb.append(", type=").append(type); sb.append('}'); return sb.toString(); } }