org.springframework.javapoet.MethodSpec Maven / Gradle / Ivy
/*
* 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 org.springframework.javapoet;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.Modifier;
import javax.lang.model.element.TypeParameterElement;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.ExecutableType;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.type.TypeVariable;
import javax.lang.model.util.Types;
import static org.springframework.javapoet.Util.checkArgument;
import static org.springframework.javapoet.Util.checkNotNull;
import static org.springframework.javapoet.Util.checkState;
/** A generated constructor or method declaration. */
public final class MethodSpec {
static final String CONSTRUCTOR = "";
public final String name;
public final CodeBlock javadoc;
public final List annotations;
public final Set modifiers;
public final List typeVariables;
public final TypeName returnType;
public final List parameters;
public final boolean varargs;
public final List exceptions;
public final CodeBlock code;
public final CodeBlock defaultValue;
private MethodSpec(Builder builder) {
CodeBlock code = builder.code.build();
checkArgument(code.isEmpty() || !builder.modifiers.contains(Modifier.ABSTRACT),
"abstract method %s cannot have code", builder.name);
checkArgument(!builder.varargs || lastParameterIsArray(builder.parameters),
"last parameter of varargs method %s must be an array", builder.name);
this.name = checkNotNull(builder.name, "name == null");
this.javadoc = builder.javadoc.build();
this.annotations = Util.immutableList(builder.annotations);
this.modifiers = Util.immutableSet(builder.modifiers);
this.typeVariables = Util.immutableList(builder.typeVariables);
this.returnType = builder.returnType;
this.parameters = Util.immutableList(builder.parameters);
this.varargs = builder.varargs;
this.exceptions = Util.immutableList(builder.exceptions);
this.defaultValue = builder.defaultValue;
this.code = code;
}
private boolean lastParameterIsArray(List parameters) {
return !parameters.isEmpty()
&& TypeName.asArray((parameters.get(parameters.size() - 1).type)) != null;
}
void emit(CodeWriter codeWriter, String enclosingName, Set implicitModifiers)
throws IOException {
codeWriter.emitJavadoc(javadocWithParameters());
codeWriter.emitAnnotations(annotations, false);
codeWriter.emitModifiers(modifiers, implicitModifiers);
if (!typeVariables.isEmpty()) {
codeWriter.emitTypeVariables(typeVariables);
codeWriter.emit(" ");
}
if (isConstructor()) {
codeWriter.emit("$L($Z", enclosingName);
} else {
codeWriter.emit("$T $L($Z", returnType, name);
}
boolean firstParameter = true;
for (Iterator i = parameters.iterator(); i.hasNext(); ) {
ParameterSpec parameter = i.next();
if (!firstParameter) codeWriter.emit(",").emitWrappingSpace();
parameter.emit(codeWriter, !i.hasNext() && varargs);
firstParameter = false;
}
codeWriter.emit(")");
if (defaultValue != null && !defaultValue.isEmpty()) {
codeWriter.emit(" default ");
codeWriter.emit(defaultValue);
}
if (!exceptions.isEmpty()) {
codeWriter.emitWrappingSpace().emit("throws");
boolean firstException = true;
for (TypeName exception : exceptions) {
if (!firstException) codeWriter.emit(",");
codeWriter.emitWrappingSpace().emit("$T", exception);
firstException = false;
}
}
if (hasModifier(Modifier.ABSTRACT)) {
codeWriter.emit(";\n");
} else if (hasModifier(Modifier.NATIVE)) {
// Code is allowed to support stuff like GWT JSNI.
codeWriter.emit(code);
codeWriter.emit(";\n");
} else {
codeWriter.emit(" {\n");
codeWriter.indent();
codeWriter.emit(code, true);
codeWriter.unindent();
codeWriter.emit("}\n");
}
codeWriter.popTypeVariables(typeVariables);
}
private CodeBlock javadocWithParameters() {
CodeBlock.Builder builder = javadoc.toBuilder();
boolean emitTagNewline = true;
for (ParameterSpec parameterSpec : parameters) {
if (!parameterSpec.javadoc.isEmpty()) {
// Emit a new line before @param section only if the method javadoc is present.
if (emitTagNewline && !javadoc.isEmpty()) builder.add("\n");
emitTagNewline = false;
builder.add("@param $L $L", parameterSpec.name, parameterSpec.javadoc);
}
}
return builder.build();
}
public boolean hasModifier(Modifier modifier) {
return modifiers.contains(modifier);
}
public boolean isConstructor() {
return name.equals(CONSTRUCTOR);
}
@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);
emit(codeWriter, "Constructor", Collections.emptySet());
return out.toString();
} catch (IOException e) {
throw new AssertionError();
}
}
public static Builder methodBuilder(String name) {
return new Builder(name);
}
public static Builder constructorBuilder() {
return new Builder(CONSTRUCTOR);
}
/**
* Returns a new method spec builder that overrides {@code method}.
*
* This will copy its visibility modifiers, type parameters, return type, name, parameters, and
* throws declarations. An {@link Override} annotation will be added.
*
*
Note that in JavaPoet 1.2 through 1.7 this method retained annotations from the method and
* parameters of the overridden method. Since JavaPoet 1.8 annotations must be added separately.
*/
public static Builder overriding(ExecutableElement method) {
checkNotNull(method, "method == null");
Element enclosingClass = method.getEnclosingElement();
if (enclosingClass.getModifiers().contains(Modifier.FINAL)) {
throw new IllegalArgumentException("Cannot override method on final class " + enclosingClass);
}
Set modifiers = method.getModifiers();
if (modifiers.contains(Modifier.PRIVATE)
|| modifiers.contains(Modifier.FINAL)
|| modifiers.contains(Modifier.STATIC)) {
throw new IllegalArgumentException("cannot override method with modifiers: " + modifiers);
}
String methodName = method.getSimpleName().toString();
MethodSpec.Builder methodBuilder = MethodSpec.methodBuilder(methodName);
methodBuilder.addAnnotation(Override.class);
modifiers = new LinkedHashSet<>(modifiers);
modifiers.remove(Modifier.ABSTRACT);
modifiers.remove(Modifier.DEFAULT);
methodBuilder.addModifiers(modifiers);
for (TypeParameterElement typeParameterElement : method.getTypeParameters()) {
TypeVariable var = (TypeVariable) typeParameterElement.asType();
methodBuilder.addTypeVariable(TypeVariableName.get(var));
}
methodBuilder.returns(TypeName.get(method.getReturnType()));
methodBuilder.addParameters(ParameterSpec.parametersOf(method));
methodBuilder.varargs(method.isVarArgs());
for (TypeMirror thrownType : method.getThrownTypes()) {
methodBuilder.addException(TypeName.get(thrownType));
}
return methodBuilder;
}
/**
* Returns a new method spec builder that overrides {@code method} as a member of {@code
* enclosing}. This will resolve type parameters: for example overriding {@link
* Comparable#compareTo} in a type that implements {@code Comparable}, the {@code T}
* parameter will be resolved to {@code Movie}.
*
* This will copy its visibility modifiers, type parameters, return type, name, parameters, and
* throws declarations. An {@link Override} annotation will be added.
*
*
Note that in JavaPoet 1.2 through 1.7 this method retained annotations from the method and
* parameters of the overridden method. Since JavaPoet 1.8 annotations must be added separately.
*/
public static Builder overriding(
ExecutableElement method, DeclaredType enclosing, Types types) {
ExecutableType executableType = (ExecutableType) types.asMemberOf(enclosing, method);
List resolvedParameterTypes = executableType.getParameterTypes();
List resolvedThrownTypes = executableType.getThrownTypes();
TypeMirror resolvedReturnType = executableType.getReturnType();
Builder builder = overriding(method);
builder.returns(TypeName.get(resolvedReturnType));
for (int i = 0, size = builder.parameters.size(); i < size; i++) {
ParameterSpec parameter = builder.parameters.get(i);
TypeName type = TypeName.get(resolvedParameterTypes.get(i));
builder.parameters.set(i, parameter.toBuilder(type, parameter.name).build());
}
builder.exceptions.clear();
for (int i = 0, size = resolvedThrownTypes.size(); i < size; i++) {
builder.addException(TypeName.get(resolvedThrownTypes.get(i)));
}
return builder;
}
public Builder toBuilder() {
Builder builder = new Builder(name);
builder.javadoc.add(javadoc);
builder.annotations.addAll(annotations);
builder.modifiers.addAll(modifiers);
builder.typeVariables.addAll(typeVariables);
builder.returnType = returnType;
builder.parameters.addAll(parameters);
builder.exceptions.addAll(exceptions);
builder.code.add(code);
builder.varargs = varargs;
builder.defaultValue = defaultValue;
return builder;
}
public static final class Builder {
private String name;
private final CodeBlock.Builder javadoc = CodeBlock.builder();
private TypeName returnType;
private final Set exceptions = new LinkedHashSet<>();
private final CodeBlock.Builder code = CodeBlock.builder();
private boolean varargs;
private CodeBlock defaultValue;
public final List typeVariables = new ArrayList<>();
public final List annotations = new ArrayList<>();
public final List modifiers = new ArrayList<>();
public final List parameters = new ArrayList<>();
private Builder(String name) {
setName(name);
}
public Builder setName(String name) {
checkNotNull(name, "name == null");
checkArgument(name.equals(CONSTRUCTOR) || SourceVersion.isName(name),
"not a valid name: %s", name);
this.name = name;
this.returnType = name.equals(CONSTRUCTOR) ? null : TypeName.VOID;
return this;
}
public Builder addJavadoc(String format, Object... args) {
javadoc.add(format, args);
return this;
}
public Builder addJavadoc(CodeBlock block) {
javadoc.add(block);
return this;
}
public Builder addAnnotations(Iterable annotationSpecs) {
checkArgument(annotationSpecs != null, "annotationSpecs == null");
for (AnnotationSpec annotationSpec : annotationSpecs) {
this.annotations.add(annotationSpec);
}
return this;
}
public Builder addAnnotation(AnnotationSpec annotationSpec) {
this.annotations.add(annotationSpec);
return this;
}
public Builder addAnnotation(ClassName annotation) {
this.annotations.add(AnnotationSpec.builder(annotation).build());
return this;
}
public Builder addAnnotation(Class annotation) {
return addAnnotation(ClassName.get(annotation));
}
public Builder addModifiers(Modifier... modifiers) {
checkNotNull(modifiers, "modifiers == null");
Collections.addAll(this.modifiers, modifiers);
return this;
}
public Builder addModifiers(Iterable modifiers) {
checkNotNull(modifiers, "modifiers == null");
for (Modifier modifier : modifiers) {
this.modifiers.add(modifier);
}
return this;
}
public Builder addTypeVariables(Iterable typeVariables) {
checkArgument(typeVariables != null, "typeVariables == null");
for (TypeVariableName typeVariable : typeVariables) {
this.typeVariables.add(typeVariable);
}
return this;
}
public Builder addTypeVariable(TypeVariableName typeVariable) {
typeVariables.add(typeVariable);
return this;
}
public Builder returns(TypeName returnType) {
checkState(!name.equals(CONSTRUCTOR), "constructor cannot have return type.");
this.returnType = returnType;
return this;
}
public Builder returns(Type returnType) {
return returns(TypeName.get(returnType));
}
public Builder addParameters(Iterable parameterSpecs) {
checkArgument(parameterSpecs != null, "parameterSpecs == null");
for (ParameterSpec parameterSpec : parameterSpecs) {
this.parameters.add(parameterSpec);
}
return this;
}
public Builder addParameter(ParameterSpec parameterSpec) {
this.parameters.add(parameterSpec);
return this;
}
public Builder addParameter(TypeName type, String name, Modifier... modifiers) {
return addParameter(ParameterSpec.builder(type, name, modifiers).build());
}
public Builder addParameter(Type type, String name, Modifier... modifiers) {
return addParameter(TypeName.get(type), name, modifiers);
}
public Builder varargs() {
return varargs(true);
}
public Builder varargs(boolean varargs) {
this.varargs = varargs;
return this;
}
public Builder addExceptions(Iterable exceptions) {
checkArgument(exceptions != null, "exceptions == null");
for (TypeName exception : exceptions) {
this.exceptions.add(exception);
}
return this;
}
public Builder addException(TypeName exception) {
this.exceptions.add(exception);
return this;
}
public Builder addException(Type exception) {
return addException(TypeName.get(exception));
}
public Builder addCode(String format, Object... args) {
code.add(format, args);
return this;
}
public Builder addNamedCode(String format, Map args) {
code.addNamed(format, args);
return this;
}
public Builder addCode(CodeBlock codeBlock) {
code.add(codeBlock);
return this;
}
public Builder addComment(String format, Object... args) {
code.add("// " + format + "\n", args);
return this;
}
public Builder defaultValue(String format, Object... args) {
return defaultValue(CodeBlock.of(format, args));
}
public Builder defaultValue(CodeBlock codeBlock) {
checkState(this.defaultValue == null, "defaultValue was already set");
this.defaultValue = checkNotNull(codeBlock, "codeBlock == null");
return this;
}
/**
* @param controlFlow the control flow construct and its code, such as "if (foo == 5)".
* Shouldn't contain braces or newline characters.
*/
public Builder beginControlFlow(String controlFlow, Object... args) {
code.beginControlFlow(controlFlow, args);
return this;
}
/**
* @param codeBlock the control flow construct and its code, such as "if (foo == 5)".
* Shouldn't contain braces or newline characters.
*/
public Builder beginControlFlow(CodeBlock codeBlock) {
return beginControlFlow("$L", codeBlock);
}
/**
* @param controlFlow the control flow construct and its code, such as "else if (foo == 10)".
* Shouldn't contain braces or newline characters.
*/
public Builder nextControlFlow(String controlFlow, Object... args) {
code.nextControlFlow(controlFlow, args);
return this;
}
/**
* @param codeBlock the control flow construct and its code, such as "else if (foo == 10)".
* Shouldn't contain braces or newline characters.
*/
public Builder nextControlFlow(CodeBlock codeBlock) {
return nextControlFlow("$L", codeBlock);
}
public Builder endControlFlow() {
code.endControlFlow();
return this;
}
/**
* @param controlFlow the optional control flow construct and its code, such as
* "while(foo == 20)". Only used for "do/while" control flows.
*/
public Builder endControlFlow(String controlFlow, Object... args) {
code.endControlFlow(controlFlow, args);
return this;
}
/**
* @param codeBlock the optional control flow construct and its code, such as
* "while(foo == 20)". Only used for "do/while" control flows.
*/
public Builder endControlFlow(CodeBlock codeBlock) {
return endControlFlow("$L", codeBlock);
}
public Builder addStatement(String format, Object... args) {
code.addStatement(format, args);
return this;
}
public Builder addStatement(CodeBlock codeBlock) {
code.addStatement(codeBlock);
return this;
}
public MethodSpec build() {
return new MethodSpec(this);
}
}
}