Add Record Class for java16

src/main/java/com/squareup/javapoet/MethodSpec.java

@@ -42,7 +42,7 @@
 /** A generated constructor or method declaration. */
 public final class MethodSpec {
  static final String CONSTRUCTOR = "<init>";
-
+ static final String COMPACT_CONSTRUCTOR = "compact";
  public final String name;
  public final CodeBlock javadoc;
  public final List<AnnotationSpec> annotations;
@@ -93,6 +93,8 @@ void emit(CodeWriter codeWriter, String enclosingName, Set<Modifier> implicitMod
 
  if (isConstructor()) {
  codeWriter.emit("$L($Z", enclosingName);
+ } else if(isCompactConstructor()){
+ codeWriter.emit("$L",enclosingName);
  } else {
  codeWriter.emit("$T $L($Z", returnType, name);
  }
@@ -105,7 +107,7 @@ void emit(CodeWriter codeWriter, String enclosingName, Set<Modifier> implicitMod
  firstParameter = false;
  }
 
- codeWriter.emit(")");
+ if(!isCompactConstructor()) codeWriter.emit(")");
 
  if (defaultValue != null && !defaultValue.isEmpty()) {
  codeWriter.emit(" default ");
@@ -161,6 +163,9 @@ public boolean hasModifier(Modifier modifier) {
  public boolean isConstructor() {
  return name.equals(CONSTRUCTOR);
  }
+ public boolean isCompactConstructor() {
+ return name.equals(COMPACT_CONSTRUCTOR);
+ }
 
  @Override public boolean equals(Object o) {
  if (this == o) return true;
@@ -191,6 +196,9 @@ public static Builder methodBuilder(String name) {
  public static Builder constructorBuilder() {
  return new Builder(CONSTRUCTOR);
  }
+ public static Builder CompactConstructorBuilder() {
+ return new Builder(COMPACT_CONSTRUCTOR);
+ }
 
  /**
  * Returns a new method spec builder that overrides {@code method}.

src/main/java/com/squareup/javapoet/TypeSpec.java

@@ -56,6 +56,7 @@ public final class TypeSpec {
  public final TypeName superclass;
  public final List<TypeName> superinterfaces;
  public final Map<String, TypeSpec> enumConstants;
+ public final Map<String, TypeName> recordArguments;
  public final List<FieldSpec> fieldSpecs;
  public final CodeBlock staticBlock;
  public final CodeBlock initializerBlock;
@@ -76,6 +77,7 @@ private TypeSpec(Builder builder) {
  this.superclass = builder.superclass;
  this.superinterfaces = Util.immutableList(builder.superinterfaces);
  this.enumConstants = Util.immutableMap(builder.enumConstants);
+ this.recordArguments = Util.immutableMap(builder.recordArguments);
  this.fieldSpecs = Util.immutableList(builder.fieldSpecs);
  this.staticBlock = builder.staticBlock.build();
  this.initializerBlock = builder.initializerBlock.build();
@@ -110,6 +112,7 @@ private TypeSpec(TypeSpec type) {
  this.superclass = null;
  this.superinterfaces = Collections.emptyList();
  this.enumConstants = Collections.emptyMap();
+ this.recordArguments = Collections.emptyMap();
  this.fieldSpecs = Collections.emptyList();
  this.staticBlock = type.staticBlock;
  this.initializerBlock = type.initializerBlock;
@@ -148,6 +151,14 @@ public static Builder enumBuilder(ClassName className) {
  return enumBuilder(checkNotNull(className, "className == null").simpleName());
  }
 
+ public static Builder recordBuilder(String name) {
+ return new Builder(Kind.RECORD, checkNotNull(name, "name == null"), null);
+ }
+
+ public static Builder recordBuilder(ClassName className) {
+ return recordBuilder(checkNotNull(className, "className == null").simpleName());
+ }
+
  public static Builder anonymousClassBuilder(String typeArgumentsFormat, Object... args) {
  return anonymousClassBuilder(CodeBlock.of(typeArgumentsFormat, args));
  }
@@ -164,6 +175,7 @@ public static Builder annotationBuilder(ClassName className) {
  return annotationBuilder(checkNotNull(className, "className == null").simpleName());
  }
 
+
  public Builder toBuilder() {
  Builder builder = new Builder(kind, name, anonymousTypeArguments);
  builder.javadoc.add(javadoc);
@@ -256,7 +268,19 @@ void emit(CodeWriter codeWriter, String enumName, Set<Modifier> implicitModifier
  }
 
  codeWriter.popType();
-
+ if (kind == Kind.RECORD){
+ codeWriter.emit("(");
+ boolean firstMember = true;
+ for (Iterator<Map.Entry<String, TypeName>> i = recordArguments.entrySet().iterator(); i.hasNext(); ) {
+// for (FieldSpec fieldSpec : fieldSpecs) {
+ Map.Entry<String, TypeName> entry = i.next();
+ codeWriter.emit(CodeBlock.builder().add("$T "+entry.getKey(),entry.getValue()).build());
+// fieldSpec.emit(codeWriter, kind.implicitFieldModifiers);
+ if (i.hasNext()) codeWriter.emit(", ");
+ firstMember = false;
+ }
+ codeWriter.emit(")");
+ }
  codeWriter.emit(" {\n");
  }
 
@@ -373,6 +397,11 @@ public enum Kind {
  Collections.emptySet(),
  Collections.emptySet(),
  Collections.emptySet()),
+ RECORD(
+ Collections.emptySet(),
+ Collections.emptySet(),
+ Collections.emptySet(),
+ Collections.emptySet()),
 
  INTERFACE(
  Util.immutableSet(Arrays.asList(Modifier.PUBLIC, Modifier.STATIC, Modifier.FINAL)),
@@ -419,6 +448,7 @@ public static final class Builder {
  private final CodeBlock.Builder initializerBlock = CodeBlock.builder();
 
  public final Map<String, TypeSpec> enumConstants = new LinkedHashMap<>();
+ public final Map<String, TypeName> recordArguments = new LinkedHashMap<>();
  public final List<AnnotationSpec> annotations = new ArrayList<>();
  public final List<Modifier> modifiers = new ArrayList<>();
  public final List<TypeVariableName> typeVariables = new ArrayList<>();
@@ -608,7 +638,14 @@ public Builder addField(TypeName type, String name, Modifier... modifiers) {
  public Builder addField(Type type, String name, Modifier... modifiers) {
  return addField(TypeName.get(type), name, modifiers);
  }
-
+ public Builder addRecord(TypeName type, String name) {
+ this.recordArguments.put(name,type);
+ return this;
+ }
+ public Builder addRecord(Type type, String name) {
+ this.recordArguments.put(name,TypeName.get(type));
+ return this;
+ }
  public Builder addStaticBlock(CodeBlock block) {
  staticBlock.beginControlFlow("static").add(block).endControlFlow();
  return this;

src/test/java/RecordExample.java

@@ -0,0 +1,51 @@
+import com.squareup.javapoet.ClassName;
+import com.squareup.javapoet.JavaFile;
+import com.squareup.javapoet.MethodSpec;
+import com.squareup.javapoet.TypeSpec;
+
+import javax.lang.model.element.Modifier;
+import java.io.IOException;
+
+public class RecordExample {
+ public static void main(String[] args) throws IOException {
+ TypeSpec record = TypeSpec.recordBuilder("Employee")
+ .addModifiers(Modifier.PUBLIC)
+ .addField(int.class, "empToken", Modifier.STATIC)
+ .addRecord(int.class, "id")
+ .addRecord(String.class, "firstName")
+ .addRecord(String.class, "lastName")
+ .addMethod(MethodSpec.CompactConstructorBuilder()
+ .addCode("if (id < 100) {\n" +
+ " throw new IllegalArgumentException(" +
+ " \"Employee Id cannot be below 100.\");\n" +
+ "}\n" +
+ "if (firstName.length() < 2) {\n" +
+ " throw new IllegalArgumentException(\n" +
+ " \"First name must be 2 characters or more.\");\n" +
+ "}")
+ .addModifiers(Modifier.PUBLIC).build())
+ .addMethod(MethodSpec.constructorBuilder()
+ .addParameter(int.class, "id")
+ .addParameter(String.class, "lastName")
+ .addStatement("this(id, firstName, null)").build())
+ .addMethod(MethodSpec.methodBuilder("getFullName")
+ .addCode("if (lastName == null)\n" +
+ " System.out.println(firstName());\n" +
+ "\n" +
+ "else\n" +
+ " System.out.println(firstName() + \" \"\n" +
+ " + lastName());")
+ .build())
+ .addMethod(MethodSpec.methodBuilder("generateEmployeeToken")
+ .addModifiers(Modifier.PUBLIC, Modifier.STATIC)
+ .returns(int.class)
+ .addCode("return ++empToken;")
+ .build())
+ .build();
+
+ JavaFile javaFile = JavaFile.builder("com.example.record", record)
+ .build();
+
+ javaFile.writeTo(System.out);
+ }
+}