com.squareup.javapoet.AnnotationSpec Maven / Gradle / Ivy
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With inspiration from other libraries
/*
* Copyright (C) 2015 Square, Inc.
*
* 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.squareup.javapoet;
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.AnnotationValue;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.SimpleAnnotationValueVisitor7;
import static com.squareup.javapoet.Util.characterLiteralWithoutSingleQuotes;
import static com.squareup.javapoet.Util.checkNotNull;
/** A generated annotation on a declaration. */
public final class AnnotationSpec {
public final TypeName type;
public final Map> members;
private AnnotationSpec(Builder builder) {
this.type = builder.type;
this.members = Util.immutableMultimap(builder.members);
}
void emit(CodeWriter codeWriter, boolean inline) throws IOException {
String whitespace = inline ? "" : "\n";
String memberSeparator = inline ? ", " : ",\n";
if (members.isEmpty()) {
// @Singleton
codeWriter.emit("@$T", type);
} else if (members.size() == 1 && members.containsKey("value")) {
// @Named("foo")
codeWriter.emit("@$T(", type);
emitAnnotationValues(codeWriter, whitespace, memberSeparator, members.get("value"));
codeWriter.emit(")");
} else {
// Inline:
// @Column(name = "updated_at", nullable = false)
//
// Not inline:
// @Column(
// name = "updated_at",
// nullable = false
// )
codeWriter.emit("@$T(" + whitespace, type);
codeWriter.indent(2);
for (Iterator>> i
= members.entrySet().iterator(); i.hasNext(); ) {
Map.Entry> entry = i.next();
codeWriter.emit("$L = ", entry.getKey());
emitAnnotationValues(codeWriter, whitespace, memberSeparator, entry.getValue());
if (i.hasNext()) codeWriter.emit(memberSeparator);
}
codeWriter.unindent(2);
codeWriter.emit(whitespace + ")");
}
}
private void emitAnnotationValues(CodeWriter codeWriter, String whitespace,
String memberSeparator, List values) throws IOException {
if (values.size() == 1) {
codeWriter.indent(2);
codeWriter.emit(values.get(0));
codeWriter.unindent(2);
return;
}
codeWriter.emit("{" + whitespace);
codeWriter.indent(2);
boolean first = true;
for (CodeBlock codeBlock : values) {
if (!first) codeWriter.emit(memberSeparator);
codeWriter.emit(codeBlock);
first = false;
}
codeWriter.unindent(2);
codeWriter.emit(whitespace + "}");
}
public static AnnotationSpec get(Annotation annotation) {
return get(annotation, false);
}
public static AnnotationSpec get(Annotation annotation, boolean includeDefaultValues) {
Builder builder = builder(annotation.annotationType());
try {
Method[] methods = annotation.annotationType().getDeclaredMethods();
Arrays.sort(methods, new Comparator() {
@Override
public int compare(Method m1, Method m2) {
return m1.getName().compareTo(m2.getName());
}
});
for (Method method : methods) {
Object value = method.invoke(annotation);
if (!includeDefaultValues) {
if (Objects.deepEquals(value, method.getDefaultValue())) {
continue;
}
}
if (value.getClass().isArray()) {
for (int i = 0; i < Array.getLength(value); i++) {
builder.addMemberForValue(method.getName(), Array.get(value, i));
}
continue;
}
if (value instanceof Annotation) {
builder.addMember(method.getName(), "$L", get((Annotation) value));
continue;
}
builder.addMemberForValue(method.getName(), value);
}
} catch (Exception e) {
throw new RuntimeException("Reflecting " + annotation + " failed!", e);
}
return builder.build();
}
public static AnnotationSpec get(AnnotationMirror annotation) {
TypeElement element = (TypeElement) annotation.getAnnotationType().asElement();
AnnotationSpec.Builder builder = AnnotationSpec.builder(ClassName.get(element));
Visitor visitor = new Visitor(builder);
for (ExecutableElement executableElement : annotation.getElementValues().keySet()) {
String name = executableElement.getSimpleName().toString();
AnnotationValue value = annotation.getElementValues().get(executableElement);
value.accept(visitor, name);
}
return builder.build();
}
public static Builder builder(ClassName type) {
checkNotNull(type, "type == null");
return new Builder(type);
}
public static Builder builder(Class type) {
return builder(ClassName.get(type));
}
public Builder toBuilder() {
Builder builder = new Builder(type);
for (Map.Entry> entry : members.entrySet()) {
builder.members.put(entry.getKey(), new ArrayList<>(entry.getValue()));
}
return builder;
}
@Override public boolean equals(Object o) {
if (this == o) return true;
if (o == null) return false;
if (getClass() != o.getClass()) return false;
return toString().equals(o.toString());
}
@Override public int hashCode() {
return toString().hashCode();
}
@Override public String toString() {
StringBuilder out = new StringBuilder();
try {
CodeWriter codeWriter = new CodeWriter(out);
codeWriter.emit("$L", this);
return out.toString();
} catch (IOException e) {
throw new AssertionError();
}
}
public static final class Builder {
private final TypeName type;
private final Map> members = new LinkedHashMap<>();
private Builder(TypeName type) {
this.type = type;
}
public Builder addMember(String name, String format, Object... args) {
return addMember(name, CodeBlock.of(format, args));
}
public Builder addMember(String name, CodeBlock codeBlock) {
List values = members.get(name);
if (values == null) {
values = new ArrayList<>();
members.put(name, values);
}
values.add(codeBlock);
return this;
}
/**
* Delegates to {@link #addMember(String, String, Object...)}, with parameter {@code format}
* depending on the given {@code value} object. Falls back to {@code "$L"} literal format if
* the class of the given {@code value} object is not supported.
*/
Builder addMemberForValue(String memberName, Object value) {
checkNotNull(memberName, "memberName == null");
checkNotNull(value, "value == null, constant non-null value expected for %s", memberName);
if (value instanceof Class) {
return addMember(memberName, "$T.class", value);
}
if (value instanceof Enum) {
return addMember(memberName, "$T.$L", value.getClass(), ((Enum) value).name());
}
if (value instanceof String) {
return addMember(memberName, "$S", value);
}
if (value instanceof Float) {
return addMember(memberName, "$Lf", value);
}
if (value instanceof Character) {
return addMember(memberName, "'$L'", characterLiteralWithoutSingleQuotes((char) value));
}
return addMember(memberName, "$L", value);
}
public AnnotationSpec build() {
return new AnnotationSpec(this);
}
}
/**
* Annotation value visitor adding members to the given builder instance.
*/
private static class Visitor extends SimpleAnnotationValueVisitor7 {
final Builder builder;
Visitor(Builder builder) {
super(builder);
this.builder = builder;
}
@Override protected Builder defaultAction(Object o, String name) {
return builder.addMemberForValue(name, o);
}
@Override public Builder visitAnnotation(AnnotationMirror a, String name) {
return builder.addMember(name, "$L", get(a));
}
@Override public Builder visitEnumConstant(VariableElement c, String name) {
return builder.addMember(name, "$T.$L", c.asType(), c.getSimpleName());
}
@Override public Builder visitType(TypeMirror t, String name) {
return builder.addMember(name, "$T.class", t);
}
@Override public Builder visitArray(List values, String name) {
for (AnnotationValue value : values) {
value.accept(this, name);
}
return builder;
}
}
}