flink-core/src/test/java/org/apache/flink/api/java/tuple/TupleGenerator.java - flink - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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.apache.flink.api.java.tuple;

 import org.apache.flink.util.FileUtils;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.Scanner;

 /**
  * Source code generator for tuple classes and classes which depend on the arity of tuples.
  *
  * <p>This class is responsible for generating the various {@link Tuple} and TupleBuilder classes.
  */
 class TupleGenerator {

 	// Parameters for tuple classes

 	private static final String ROOT_DIRECTORY = "./flink-core/src/main/java";

 	private static final String PACKAGE = "org.apache.flink.api.java.tuple";

 	private static final String BUILDER_SUFFIX = "builder";

 	private static final String GEN_TYPE_PREFIX = "T";

 	// Parameters for tuple-dependent classes
 	private static final String BEGIN_INDICATOR = "BEGIN_OF_TUPLE_DEPENDENT_CODE";

 	private static final String END_INDICATOR = "END_OF_TUPLE_DEPENDENT_CODE";

 	// Parameters for TupleTypeInfo
 	private static final String TUPLE_PACKAGE = "org.apache.flink.api.java.tuple";

 	private static final String TUPLE_CLASSNAME = "Tuple";

 	// min. and max. tuple arity
 	private static final int FIRST = 1;

 	private static final int LAST = 25;

 	public static void main(String[] args) throws Exception {
 		System.err.println("Current directory " + System.getProperty("user.dir"));
 		String rootDir = ROOT_DIRECTORY;
 		if (args.length > 0) {
 			rootDir = args[0] + "/" + ROOT_DIRECTORY;
 		}
 		System.err.println("Using root directory: " + rootDir);
 		File root = new File(rootDir);

 		createTupleClasses(root);

 		createTupleBuilderClasses(root);

 		modifyTupleType(root);

 	}

 	private static File getPackage(File root, String packageString) {
 		File dir = new File(root, packageString.replace('.', '/'));
 		if (!dir.exists() && dir.isDirectory()) {
 			System.err.println("None existent directory: " + dir.getAbsolutePath());
 			System.exit(1);
 		}
 		return dir;
 	}

 	private static void insertCodeIntoFile(String code, File file) throws IOException {
 		String fileContent = FileUtils.readFileUtf8(file);

 		try (Scanner s = new Scanner(fileContent)) {
 			StringBuilder sb = new StringBuilder();
 			String line;

 			boolean indicatorFound = false;

 			// add file beginning
 			while (s.hasNextLine() && (line = s.nextLine()) != null) {
 				sb.append(line).append("\n");
 				if (line.contains(BEGIN_INDICATOR)) {
 					indicatorFound = true;
 					break;
 				}
 			}

 			if (!indicatorFound) {
 				System.out.println("No indicator found in '" + file + "'. Will skip code generation.");
 				s.close();
 				return;
 			}

 			// add generator signature
 			sb.append("\t// GENERATED FROM ").append(TupleGenerator.class.getName()).append(".\n");

 			// add tuple dependent code
 			sb.append(code).append("\n");

 			// skip generated code
 			while (s.hasNextLine() && (line = s.nextLine()) != null) {
 				if (line.contains(END_INDICATOR)) {
 					sb.append(line).append("\n");
 					break;
 				}
 			}

 			// add file ending
 			while (s.hasNextLine() && (line = s.nextLine()) != null) {
 				sb.append(line).append("\n");
 			}
 			FileUtils.writeFileUtf8(file, sb.toString());
 		}
 	}

 	private static void modifyTupleType(File root) throws IOException {
 		// generate code
 		StringBuilder sb = new StringBuilder();
 		sb.append("\tprivate static final Class<?>[] CLASSES = new Class<?>[] {\n\t\tTuple0.class");
 		for (int i = FIRST; i <= LAST; i++) {
 			sb.append(", Tuple").append(i).append(".class");
 		}
 		sb.append("\n\t};");

 		// insert code into file
 		File dir = getPackage(root, TUPLE_PACKAGE);
 		File tupleTypeInfoClass = new File(dir, TUPLE_CLASSNAME + ".java");
 		insertCodeIntoFile(sb.toString(), tupleTypeInfoClass);
 	}

 	private static void createTupleClasses(File root) throws FileNotFoundException {
 		File dir = getPackage(root, PACKAGE);

 		for (int i = FIRST; i <= LAST; i++) {
 			File tupleFile = new File(dir, "Tuple" + i + ".java");
 				PrintWriter writer = new PrintWriter(tupleFile);
 			writeTupleClass(writer, i);
 			writer.flush();
 			writer.close();
 		}
 	}

 	private static void writeTupleClass(PrintWriter w, int numFields) {
 		final String className = "Tuple" + numFields;

 		// head
 		w.print(HEADER);

 		// package and imports
 		w.println("package " + PACKAGE + ';');
 		w.println();
 		w.println("import org.apache.flink.annotation.Public;");
 		w.println("import org.apache.flink.util.StringUtils;");
 		w.println();

 		// class declaration and class comments
 		w.println("/**");
 		w.println(" * A tuple with " + numFields + " fields. Tuples are strongly typed; each field may be of a separate type.");
 		w.println(" * The fields of the tuple can be accessed directly as public fields (f0, f1, ...) or via their position");
 		w.println(" * through the {@link #getField(int)} method. The tuple field positions start at zero.");
 		w.println(" *");
 		w.println(" * <p>Tuples are mutable types, meaning that their fields can be re-assigned. This allows functions that work");
 		w.println(" * with Tuples to reuse objects in order to reduce pressure on the garbage collector.</p>");
 		w.println(" *");
 		w.println(" * <p>Warning: If you subclass " + className + ", then be sure to either <ul>");
 		w.println(" *  <li> not add any new fields, or </li>");
 		w.println(" *  <li> make it a POJO, and always declare the element type of your DataStreams/DataSets to your descendant");
 		w.println(" *       type. (That is, if you have a \"class Foo extends " + className + "\", then don't use instances of");
 		w.println(" *       Foo in a DataStream&lt;" + className + "&gt; / DataSet&lt;" + className + "&gt;, but declare it as");
 		w.println(" *       DataStream&lt;Foo&gt; / DataSet&lt;Foo&gt;.) </li>");
 		w.println(" * </ul></p>");
 		w.println(" * @see Tuple");
 		w.println(" *");
 		for (int i = 0; i < numFields; i++) {
 			w.println(" * @param <" + GEN_TYPE_PREFIX + i + "> The type of field " + i);
 		}
 		w.println(" */");
 		w.println("@Public");
 		w.print("public class " + className + "<");
 		for (int i = 0; i < numFields; i++) {
 			if (i > 0) {
 				w.print(", ");
 			}
 			w.print(GEN_TYPE_PREFIX + i);
 		}
 		w.println("> extends Tuple {");
 		w.println();

 		w.println("\tprivate static final long serialVersionUID = 1L;");
 		w.println();

 		// fields
 		for (int i = 0; i < numFields; i++) {
 			w.println("\t/** Field " + i + " of the tuple. */");
 			w.println("\tpublic " + GEN_TYPE_PREFIX + i + " f" + i + ';');
 		}
 		w.println();

 		String paramList = "("; // This will be like "(T0 value0, T1 value1)"
 		for (int i = 0; i < numFields; i++) {
 			if (i > 0) {
 				paramList += ", ";
 			}
 			paramList += GEN_TYPE_PREFIX + i + " value" + i;
 		}
 		paramList += ")";

 		// constructors
 		w.println("\t/**");
 		w.println("\t * Creates a new tuple where all fields are null.");
 		w.println("\t */");
 		w.println("\tpublic " + className + "() {}");
 		w.println();
 		w.println("\t/**");
 		w.println("\t * Creates a new tuple and assigns the given values to the tuple's fields.");
 		w.println("\t *");
 		for (int i = 0; i < numFields; i++) {
 			w.println("\t * @param value" + i + " The value for field " + i);
 		}
 		w.println("\t */");
 		w.println("\tpublic " + className + paramList + " {");
 		for (int i = 0; i < numFields; i++) {
 			w.println("\t\tthis.f" + i + " = value" + i + ';');
 		}
 		w.println("\t}");
 		w.println();

 		// arity accessor
 		w.println("\t@Override");
 		w.println("\tpublic int getArity() {");
 		w.println("\t\treturn " + numFields + ";");
 		w.println("\t}");
 		w.println();

 		// accessor getter method
 		w.println("\t@Override");
 		w.println("\t@SuppressWarnings(\"unchecked\")");
 		w.println("\tpublic <T> T getField(int pos) {");
 		w.println("\t\tswitch(pos) {");
 		for (int i = 0; i < numFields; i++) {
 			w.println("\t\t\tcase " + i + ": return (T) this.f" + i + ';');
 		}
 		w.println("\t\t\tdefault: throw new IndexOutOfBoundsException(String.valueOf(pos));");
 		w.println("\t\t}");
 		w.println("\t}");
 		w.println();

 		// accessor setter method
 		w.println("\t@Override");
 		w.println("\t@SuppressWarnings(\"unchecked\")");
 		w.println("\tpublic <T> void setField(T value, int pos) {");
 		w.println("\t\tswitch(pos) {");
 		for (int i = 0; i < numFields; i++) {
 			w.println("\t\t\tcase " + i + ':');
 			w.println("\t\t\t\tthis.f" + i + " = (" + GEN_TYPE_PREFIX + i + ") value;");
 			w.println("\t\t\t\tbreak;");
 		}
 		w.println("\t\t\tdefault: throw new IndexOutOfBoundsException(String.valueOf(pos));");
 		w.println("\t\t}");
 		w.println("\t}");
 		w.println();

 		// accessor setter method for all fields
 		w.println("\t/**");
 		w.println("\t * Sets new values to all fields of the tuple.");
 		w.println("\t *");
 		for (int i = 0; i < numFields; i++) {
 			w.println("\t * @param value" + i + " The value for field " + i);
 		}
 		w.println("\t */");
 		w.println("\tpublic void setFields" + paramList + " {");
 		for (int i = 0; i < numFields; i++) {
 			w.println("\t\tthis.f" + i + " = value" + i + ';');
 		}
 		w.println("\t}");
 		w.println();

 		// swap method only for Tuple2
 		if (numFields == 2) {
 			w.println("\t/**");
 			w.println("\t* Returns a shallow copy of the tuple with swapped values.");
 			w.println("\t*");
 			w.println("\t* @return shallow copy of the tuple with swapped values");
 			w.println("\t*/");
 			w.println("\tpublic Tuple2<T1, T0> swap() {");
 			w.println("\t\treturn new Tuple2<T1, T0>(f1, f0);");
 			w.println("\t}");
 		}

 		// standard utilities (toString, equals, hashCode, copy)
 		w.println();
 		w.println("\t// -------------------------------------------------------------------------------------------------");
 		w.println("\t// standard utilities");
 		w.println("\t// -------------------------------------------------------------------------------------------------");
 		w.println();
 		w.println("\t/**");
 		w.println("\t * Creates a string representation of the tuple in the form");
 		w.print("\t * (f0");
 		for (int i = 1; i < numFields; i++) {
 			w.print(", f" + i);
 		}
 		w.println("),");
 		w.println("\t * where the individual fields are the value returned by calling {@link Object#toString} on that field.");
 		w.println("\t * @return The string representation of the tuple.");
 		w.println("\t */");
 		w.println("\t@Override");
 		w.println("\tpublic String toString() {");
 		w.println("\t\treturn \"(\" + StringUtils.arrayAwareToString(this.f0)");
 		for (int i = 1; i < numFields; i++) {
 			w.println("\t\t\t+ \",\" + StringUtils.arrayAwareToString(this.f" + i + ")");
 		}
 		w.println("\t\t\t+ \")\";");
 		w.println("\t}");

 		w.println();
 		w.println("\t/**");
 		w.println("\t * Deep equality for tuples by calling equals() on the tuple members.");
 		w.println("\t * @param o the object checked for equality");
 		w.println("\t * @return true if this is equal to o.");
 		w.println("\t */");
 		w.println("\t@Override");
 		w.println("\tpublic boolean equals(Object o) {");
 		w.println("\t\tif (this == o) {");
 		w.println("\t\t\treturn true;");
 		w.println("\t\t}");
 		w.println("\t\tif (!(o instanceof " + className + ")) {");
 		w.println("\t\t\treturn false;");
 		w.println("\t\t}");
 		w.println("\t\t@SuppressWarnings(\"rawtypes\")");
 		w.println("\t\t" + className + " tuple = (" + className + ") o;");
 		for (int i = 0; i < numFields; i++) {
 			String field = "f" + i;
 			w.println("\t\tif (" + field + " != null ? !" + field + ".equals(tuple." +
 					field + ") : tuple." + field + " != null) {");
 			w.println("\t\t\treturn false;");
 			w.println("\t\t}");
 		}
 		w.println("\t\treturn true;");
 		w.println("\t}");

 		w.println();
 		w.println("\t@Override");
 		w.println("\tpublic int hashCode() {");
 		w.println("\t\tint result = f0 != null ? f0.hashCode() : 0;");
 		for (int i = 1; i < numFields; i++) {
 			String field = "f" + i;
 			w.println("\t\tresult = 31 * result + (" + field + " != null ? " + field + ".hashCode() : 0);");
 		}
 		w.println("\t\treturn result;");
 		w.println("\t}");

 		String tupleTypes = "";
 		for (int i = 0; i < numFields; i++) {
 			tupleTypes += "T" + i;
 			if (i < numFields - 1) {
 				tupleTypes += ", ";
 			}
 		}

 		w.println();
 		w.println("\t/**");
 		w.println("\t* Shallow tuple copy.");
 		w.println("\t* @return A new Tuple with the same fields as this.");
 		w.println("\t*/");
 		w.println("\t@Override");
 		w.println("\t@SuppressWarnings(\"unchecked\")");
 		w.println("\tpublic " + className + "<" + tupleTypes + "> copy() {");

 		w.print("\t\treturn new " + className + "<>(this.f0");
 		if (numFields > 1) {
 			w.println(",");
 		}
 		for (int i = 1; i < numFields; i++) {
 			String field = "f" + i;
 			w.print("\t\t\tthis." + field);
 			if (i < numFields - 1) {
 				w.println(",");
 			}
 		}
 		w.println(");");
 		w.println("\t}");

 		w.println();
 		w.println("\t/**");
 		w.println("\t * Creates a new tuple and assigns the given values to the tuple's fields.");
 		w.println("\t * This is more convenient than using the constructor, because the compiler can");
 		w.println("\t * infer the generic type arguments implicitly. For example:");
 		w.println("\t * {@code Tuple3.of(n, x, s)}");
 		w.println("\t * instead of");
 		w.println("\t * {@code new Tuple3<Integer, Double, String>(n, x, s)}");
 		w.println("\t */");
 		w.println("\tpublic static <" + tupleTypes + "> " + className + "<" + tupleTypes + "> of" + paramList + " {");

 		w.print("\t\treturn new " + className + "<>(value0");
 		if (numFields > 1) {
 			w.println(",");
 		}
 		for (int i = 1; i < numFields; i++) {
 			w.print("\t\t\tvalue" + i);
 			if (i < numFields - 1) {
 				w.println(",");
 			}
 		}
 		w.println(");");
 		w.println("\t}");

 		// foot
 		w.println("}");
 	}

 	private static void createTupleBuilderClasses(File root) throws FileNotFoundException {
 		File dir = getPackage(root, PACKAGE + "." + BUILDER_SUFFIX);

 		for (int i = FIRST; i <= LAST; i++) {
 			File tupleFile = new File(dir, "Tuple" + i + "Builder.java");
 			PrintWriter writer = new PrintWriter(tupleFile);
 			writeTupleBuilderClass(writer, i);
 			writer.flush();
 			writer.close();
 		}
 	}

 	private static void printGenericsString(PrintWriter w, int numFields){
 		w.print("<");
 		for (int i = 0; i < numFields; i++) {
 			if (i > 0) {
 				w.print(", ");
 			}
 			w.print(GEN_TYPE_PREFIX + i);
 		}
 		w.print(">");
 	}

 	private static void writeTupleBuilderClass(PrintWriter w, int numFields) {
 		final String className = "Tuple" + numFields + "Builder";

 		// head
 		w.print(HEADER);

 		// package and imports
 		w.println("package " + PACKAGE + "." + BUILDER_SUFFIX + ';');
 		w.println();
 		w.println("import org.apache.flink.annotation.Public;");
 		w.println("import " + PACKAGE + ".Tuple" + numFields + ";");
 		w.println();
 		w.println("import java.util.ArrayList;");
 		w.println("import java.util.List;");
 		w.println();

 		// class javadoc
 		w.println("/**");
 		w.println(" * A builder class for {@link Tuple" + numFields + "}.");
 		w.println(" *");
 		for (int i = 0; i < numFields; i++) {
 			w.println(" * @param <" + GEN_TYPE_PREFIX + i + "> The type of field " + i);
 		}
 		w.println(" */");

 		// class declaration
 		w.println("@Public");
 		w.print("public class " + className);
 		printGenericsString(w, numFields);
 		w.println(" {");
 		w.println();

 		// Class-Attributes - a list of tuples
 		w.print("\tprivate List<Tuple" + numFields);
 		printGenericsString(w, numFields);
 		w.println("> tuples = new ArrayList<>();");
 		w.println();

 		// add(...) function for adding a single tuple
 		w.print("\tpublic " + className);
 		printGenericsString(w, numFields);
 		w.print(" add(");
 		for (int i = 0; i < numFields; i++) {
 			if (i > 0) {
 				w.print(", ");
 			}
 			w.print(GEN_TYPE_PREFIX + i + " value" + i);
 		}
 		w.println("){");
 		w.print("\t\ttuples.add(new Tuple" + numFields + "<>(");
 		for (int i = 0; i < numFields; i++) {
 			if (i > 0) {
 				w.print(", ");
 			}
 			w.print("value" + i);
 		}
 		w.println("));");
 		w.println("\t\treturn this;");
 		w.println("\t}");
 		w.println();

 		// build() function, returns an array of tuples
 		w.println("\t@SuppressWarnings(\"unchecked\")");
 		w.print("\tpublic Tuple" + numFields);
 		printGenericsString(w, numFields);
 		w.println("[] build(){");
 		w.println("\t\treturn tuples.toArray(new Tuple" + numFields + "[tuples.size()]);");
 		w.println("\t}");

 		// foot
 		w.println("}");
 	}

 	private static final String HEADER =
 		"/*\n"
 		+ " * Licensed to the Apache Software Foundation (ASF) under one\n"
 		+ " * or more contributor license agreements.  See the NOTICE file\n"
 		+ " * distributed with this work for additional information\n"
 		+ " * regarding copyright ownership.  The ASF licenses this file\n"
 		+ " * to you under the Apache License, Version 2.0 (the\n"
 		+ " * \"License\"); you may not use this file except in compliance\n"
 		+ " * with the License.  You may obtain a copy of the License at\n"
 		+ " *\n"
 		+ " *     http://www.apache.org/licenses/LICENSE-2.0\n"
 		+ " *\n"
 		+ " * Unless required by applicable law or agreed to in writing, software\n"
 		+ " * distributed under the License is distributed on an \"AS IS\" BASIS,\n"
 		+ " * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n"
 		+ " * See the License for the specific language governing permissions and\n"
 		+ " * limitations under the License.\n"
 		+ " */" +
 		"\n" +
 		"\n" +
 		"// --------------------------------------------------------------\n" +
 		"//  THIS IS A GENERATED SOURCE FILE. DO NOT EDIT!\n" +
 		"//  GENERATED FROM " + TupleGenerator.class.getName() + ".\n" +
 		"// --------------------------------------------------------------\n\n";
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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.apache.flink.api.java.tuple;

	import org.apache.flink.util.FileUtils;

	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.io.PrintWriter;
	import java.util.Scanner;

	/**
	* Source code generator for tuple classes and classes which depend on the arity of tuples.
	*
	* <p>This class is responsible for generating the various {@link Tuple} and TupleBuilder classes.
	*/
	class TupleGenerator {

	// Parameters for tuple classes

	private static final String ROOT_DIRECTORY = "./flink-core/src/main/java";

	private static final String PACKAGE = "org.apache.flink.api.java.tuple";

	private static final String BUILDER_SUFFIX = "builder";

	private static final String GEN_TYPE_PREFIX = "T";

	// Parameters for tuple-dependent classes
	private static final String BEGIN_INDICATOR = "BEGIN_OF_TUPLE_DEPENDENT_CODE";

	private static final String END_INDICATOR = "END_OF_TUPLE_DEPENDENT_CODE";

	// Parameters for TupleTypeInfo
	private static final String TUPLE_PACKAGE = "org.apache.flink.api.java.tuple";

	private static final String TUPLE_CLASSNAME = "Tuple";

	// min. and max. tuple arity
	private static final int FIRST = 1;

	private static final int LAST = 25;

	public static void main(String[] args) throws Exception {
	System.err.println("Current directory " + System.getProperty("user.dir"));
	String rootDir = ROOT_DIRECTORY;
	if (args.length > 0) {
	rootDir = args[0] + "/" + ROOT_DIRECTORY;
	}
	System.err.println("Using root directory: " + rootDir);
	File root = new File(rootDir);

	createTupleClasses(root);

	createTupleBuilderClasses(root);

	modifyTupleType(root);

	}

	private static File getPackage(File root, String packageString) {
	File dir = new File(root, packageString.replace('.', '/'));
	if (!dir.exists() && dir.isDirectory()) {
	System.err.println("None existent directory: " + dir.getAbsolutePath());
	System.exit(1);
	}
	return dir;
	}

	private static void insertCodeIntoFile(String code, File file) throws IOException {
	String fileContent = FileUtils.readFileUtf8(file);

	try (Scanner s = new Scanner(fileContent)) {
	StringBuilder sb = new StringBuilder();
	String line;

	boolean indicatorFound = false;

	// add file beginning
	while (s.hasNextLine() && (line = s.nextLine()) != null) {
	sb.append(line).append("\n");
	if (line.contains(BEGIN_INDICATOR)) {
	indicatorFound = true;
	break;
	}
	}

	if (!indicatorFound) {
	System.out.println("No indicator found in '" + file + "'. Will skip code generation.");
	s.close();
	return;
	}

	// add generator signature
	sb.append("\t// GENERATED FROM ").append(TupleGenerator.class.getName()).append(".\n");

	// add tuple dependent code
	sb.append(code).append("\n");

	// skip generated code
	while (s.hasNextLine() && (line = s.nextLine()) != null) {
	if (line.contains(END_INDICATOR)) {
	sb.append(line).append("\n");
	break;
	}
	}

	// add file ending
	while (s.hasNextLine() && (line = s.nextLine()) != null) {
	sb.append(line).append("\n");
	}
	FileUtils.writeFileUtf8(file, sb.toString());
	}
	}

	private static void modifyTupleType(File root) throws IOException {
	// generate code
	StringBuilder sb = new StringBuilder();
	sb.append("\tprivate static final Class<?>[] CLASSES = new Class<?>[] {\n\t\tTuple0.class");
	for (int i = FIRST; i <= LAST; i++) {
	sb.append(", Tuple").append(i).append(".class");
	}
	sb.append("\n\t};");

	// insert code into file
	File dir = getPackage(root, TUPLE_PACKAGE);
	File tupleTypeInfoClass = new File(dir, TUPLE_CLASSNAME + ".java");
	insertCodeIntoFile(sb.toString(), tupleTypeInfoClass);
	}

	private static void createTupleClasses(File root) throws FileNotFoundException {
	File dir = getPackage(root, PACKAGE);

	for (int i = FIRST; i <= LAST; i++) {
	File tupleFile = new File(dir, "Tuple" + i + ".java");
	PrintWriter writer = new PrintWriter(tupleFile);
	writeTupleClass(writer, i);
	writer.flush();
	writer.close();
	}
	}

	private static void writeTupleClass(PrintWriter w, int numFields) {
	final String className = "Tuple" + numFields;

	// head
	w.print(HEADER);

	// package and imports
	w.println("package " + PACKAGE + ';');
	w.println();
	w.println("import org.apache.flink.annotation.Public;");
	w.println("import org.apache.flink.util.StringUtils;");
	w.println();

	// class declaration and class comments
	w.println("/**");
	w.println(" * A tuple with " + numFields + " fields. Tuples are strongly typed; each field may be of a separate type.");
	w.println(" * The fields of the tuple can be accessed directly as public fields (f0, f1, ...) or via their position");
	w.println(" * through the {@link #getField(int)} method. The tuple field positions start at zero.");
	w.println(" *");
	w.println(" * <p>Tuples are mutable types, meaning that their fields can be re-assigned. This allows functions that work");
	w.println(" * with Tuples to reuse objects in order to reduce pressure on the garbage collector.</p>");
	w.println(" *");
	w.println(" * <p>Warning: If you subclass " + className + ", then be sure to either <ul>");
	w.println(" * <li> not add any new fields, or </li>");
	w.println(" * <li> make it a POJO, and always declare the element type of your DataStreams/DataSets to your descendant");
	w.println(" * type. (That is, if you have a \"class Foo extends " + className + "\", then don't use instances of");
	w.println(" * Foo in a DataStream<" + className + "> / DataSet<" + className + ">, but declare it as");
	w.println(" * DataStream<Foo> / DataSet<Foo>.) </li>");
	w.println(" * </ul></p>");
	w.println(" * @see Tuple");
	w.println(" *");
	for (int i = 0; i < numFields; i++) {
	w.println(" * @param <" + GEN_TYPE_PREFIX + i + "> The type of field " + i);
	}
	w.println(" */");
	w.println("@Public");
	w.print("public class " + className + "<");
	for (int i = 0; i < numFields; i++) {
	if (i > 0) {
	w.print(", ");
	}
	w.print(GEN_TYPE_PREFIX + i);
	}
	w.println("> extends Tuple {");
	w.println();

	w.println("\tprivate static final long serialVersionUID = 1L;");
	w.println();

	// fields
	for (int i = 0; i < numFields; i++) {
	w.println("\t/** Field " + i + " of the tuple. */");
	w.println("\tpublic " + GEN_TYPE_PREFIX + i + " f" + i + ';');
	}
	w.println();

	String paramList = "("; // This will be like "(T0 value0, T1 value1)"
	for (int i = 0; i < numFields; i++) {
	if (i > 0) {
	paramList += ", ";
	}
	paramList += GEN_TYPE_PREFIX + i + " value" + i;
	}
	paramList += ")";

	// constructors
	w.println("\t/**");
	w.println("\t * Creates a new tuple where all fields are null.");
	w.println("\t */");
	w.println("\tpublic " + className + "() {}");
	w.println();
	w.println("\t/**");
	w.println("\t * Creates a new tuple and assigns the given values to the tuple's fields.");
	w.println("\t *");
	for (int i = 0; i < numFields; i++) {
	w.println("\t * @param value" + i + " The value for field " + i);
	}
	w.println("\t */");
	w.println("\tpublic " + className + paramList + " {");
	for (int i = 0; i < numFields; i++) {
	w.println("\t\tthis.f" + i + " = value" + i + ';');
	}
	w.println("\t}");
	w.println();

	// arity accessor
	w.println("\t@Override");
	w.println("\tpublic int getArity() {");
	w.println("\t\treturn " + numFields + ";");
	w.println("\t}");
	w.println();

	// accessor getter method
	w.println("\t@Override");
	w.println("\t@SuppressWarnings(\"unchecked\")");
	w.println("\tpublic <T> T getField(int pos) {");
	w.println("\t\tswitch(pos) {");
	for (int i = 0; i < numFields; i++) {
	w.println("\t\t\tcase " + i + ": return (T) this.f" + i + ';');
	}
	w.println("\t\t\tdefault: throw new IndexOutOfBoundsException(String.valueOf(pos));");
	w.println("\t\t}");
	w.println("\t}");
	w.println();

	// accessor setter method
	w.println("\t@Override");
	w.println("\t@SuppressWarnings(\"unchecked\")");
	w.println("\tpublic <T> void setField(T value, int pos) {");
	w.println("\t\tswitch(pos) {");
	for (int i = 0; i < numFields; i++) {
	w.println("\t\t\tcase " + i + ':');
	w.println("\t\t\t\tthis.f" + i + " = (" + GEN_TYPE_PREFIX + i + ") value;");
	w.println("\t\t\t\tbreak;");
	}
	w.println("\t\t\tdefault: throw new IndexOutOfBoundsException(String.valueOf(pos));");
	w.println("\t\t}");
	w.println("\t}");
	w.println();

	// accessor setter method for all fields
	w.println("\t/**");
	w.println("\t * Sets new values to all fields of the tuple.");
	w.println("\t *");
	for (int i = 0; i < numFields; i++) {
	w.println("\t * @param value" + i + " The value for field " + i);
	}
	w.println("\t */");
	w.println("\tpublic void setFields" + paramList + " {");
	for (int i = 0; i < numFields; i++) {
	w.println("\t\tthis.f" + i + " = value" + i + ';');
	}
	w.println("\t}");
	w.println();

	// swap method only for Tuple2
	if (numFields == 2) {
	w.println("\t/**");
	w.println("\t* Returns a shallow copy of the tuple with swapped values.");
	w.println("\t*");
	w.println("\t* @return shallow copy of the tuple with swapped values");
	w.println("\t*/");
	w.println("\tpublic Tuple2<T1, T0> swap() {");
	w.println("\t\treturn new Tuple2<T1, T0>(f1, f0);");
	w.println("\t}");
	}

	// standard utilities (toString, equals, hashCode, copy)
	w.println();
	w.println("\t// -------------------------------------------------------------------------------------------------");
	w.println("\t// standard utilities");
	w.println("\t// -------------------------------------------------------------------------------------------------");
	w.println();
	w.println("\t/**");
	w.println("\t * Creates a string representation of the tuple in the form");
	w.print("\t * (f0");
	for (int i = 1; i < numFields; i++) {
	w.print(", f" + i);
	}
	w.println("),");
	w.println("\t * where the individual fields are the value returned by calling {@link Object#toString} on that field.");
	w.println("\t * @return The string representation of the tuple.");
	w.println("\t */");
	w.println("\t@Override");
	w.println("\tpublic String toString() {");
	w.println("\t\treturn \"(\" + StringUtils.arrayAwareToString(this.f0)");
	for (int i = 1; i < numFields; i++) {
	w.println("\t\t\t+ \",\" + StringUtils.arrayAwareToString(this.f" + i + ")");
	}
	w.println("\t\t\t+ \")\";");
	w.println("\t}");

	w.println();
	w.println("\t/**");
	w.println("\t * Deep equality for tuples by calling equals() on the tuple members.");
	w.println("\t * @param o the object checked for equality");
	w.println("\t * @return true if this is equal to o.");
	w.println("\t */");
	w.println("\t@Override");
	w.println("\tpublic boolean equals(Object o) {");
	w.println("\t\tif (this == o) {");
	w.println("\t\t\treturn true;");
	w.println("\t\t}");
	w.println("\t\tif (!(o instanceof " + className + ")) {");
	w.println("\t\t\treturn false;");
	w.println("\t\t}");
	w.println("\t\t@SuppressWarnings(\"rawtypes\")");
	w.println("\t\t" + className + " tuple = (" + className + ") o;");
	for (int i = 0; i < numFields; i++) {
	String field = "f" + i;
	w.println("\t\tif (" + field + " != null ? !" + field + ".equals(tuple." +
	field + ") : tuple." + field + " != null) {");
	w.println("\t\t\treturn false;");
	w.println("\t\t}");
	}
	w.println("\t\treturn true;");
	w.println("\t}");

	w.println();
	w.println("\t@Override");
	w.println("\tpublic int hashCode() {");
	w.println("\t\tint result = f0 != null ? f0.hashCode() : 0;");
	for (int i = 1; i < numFields; i++) {
	String field = "f" + i;
	w.println("\t\tresult = 31 * result + (" + field + " != null ? " + field + ".hashCode() : 0);");
	}
	w.println("\t\treturn result;");
	w.println("\t}");

	String tupleTypes = "";
	for (int i = 0; i < numFields; i++) {
	tupleTypes += "T" + i;
	if (i < numFields - 1) {
	tupleTypes += ", ";
	}
	}

	w.println();
	w.println("\t/**");
	w.println("\t* Shallow tuple copy.");
	w.println("\t* @return A new Tuple with the same fields as this.");
	w.println("\t*/");
	w.println("\t@Override");
	w.println("\t@SuppressWarnings(\"unchecked\")");
	w.println("\tpublic " + className + "<" + tupleTypes + "> copy() {");

	w.print("\t\treturn new " + className + "<>(this.f0");
	if (numFields > 1) {
	w.println(",");
	}
	for (int i = 1; i < numFields; i++) {
	String field = "f" + i;
	w.print("\t\t\tthis." + field);
	if (i < numFields - 1) {
	w.println(",");
	}
	}
	w.println(");");
	w.println("\t}");

	w.println();
	w.println("\t/**");
	w.println("\t * Creates a new tuple and assigns the given values to the tuple's fields.");
	w.println("\t * This is more convenient than using the constructor, because the compiler can");
	w.println("\t * infer the generic type arguments implicitly. For example:");
	w.println("\t * {@code Tuple3.of(n, x, s)}");
	w.println("\t * instead of");
	w.println("\t * {@code new Tuple3<Integer, Double, String>(n, x, s)}");
	w.println("\t */");
	w.println("\tpublic static <" + tupleTypes + "> " + className + "<" + tupleTypes + "> of" + paramList + " {");

	w.print("\t\treturn new " + className + "<>(value0");
	if (numFields > 1) {
	w.println(",");
	}
	for (int i = 1; i < numFields; i++) {
	w.print("\t\t\tvalue" + i);
	if (i < numFields - 1) {
	w.println(",");
	}
	}
	w.println(");");
	w.println("\t}");

	// foot
	w.println("}");
	}

	private static void createTupleBuilderClasses(File root) throws FileNotFoundException {
	File dir = getPackage(root, PACKAGE + "." + BUILDER_SUFFIX);

	for (int i = FIRST; i <= LAST; i++) {
	File tupleFile = new File(dir, "Tuple" + i + "Builder.java");
	PrintWriter writer = new PrintWriter(tupleFile);
	writeTupleBuilderClass(writer, i);
	writer.flush();
	writer.close();
	}
	}

	private static void printGenericsString(PrintWriter w, int numFields){
	w.print("<");
	for (int i = 0; i < numFields; i++) {
	if (i > 0) {
	w.print(", ");
	}
	w.print(GEN_TYPE_PREFIX + i);
	}
	w.print(">");
	}

	private static void writeTupleBuilderClass(PrintWriter w, int numFields) {
	final String className = "Tuple" + numFields + "Builder";

	// head
	w.print(HEADER);

	// package and imports
	w.println("package " + PACKAGE + "." + BUILDER_SUFFIX + ';');
	w.println();
	w.println("import org.apache.flink.annotation.Public;");
	w.println("import " + PACKAGE + ".Tuple" + numFields + ";");
	w.println();
	w.println("import java.util.ArrayList;");
	w.println("import java.util.List;");
	w.println();

	// class javadoc
	w.println("/**");
	w.println(" * A builder class for {@link Tuple" + numFields + "}.");
	w.println(" *");
	for (int i = 0; i < numFields; i++) {
	w.println(" * @param <" + GEN_TYPE_PREFIX + i + "> The type of field " + i);
	}
	w.println(" */");

	// class declaration
	w.println("@Public");
	w.print("public class " + className);
	printGenericsString(w, numFields);
	w.println(" {");
	w.println();

	// Class-Attributes - a list of tuples
	w.print("\tprivate List<Tuple" + numFields);
	printGenericsString(w, numFields);
	w.println("> tuples = new ArrayList<>();");
	w.println();

	// add(...) function for adding a single tuple
	w.print("\tpublic " + className);
	printGenericsString(w, numFields);
	w.print(" add(");
	for (int i = 0; i < numFields; i++) {
	if (i > 0) {
	w.print(", ");
	}
	w.print(GEN_TYPE_PREFIX + i + " value" + i);
	}
	w.println("){");
	w.print("\t\ttuples.add(new Tuple" + numFields + "<>(");
	for (int i = 0; i < numFields; i++) {
	if (i > 0) {
	w.print(", ");
	}
	w.print("value" + i);
	}
	w.println("));");
	w.println("\t\treturn this;");
	w.println("\t}");
	w.println();

	// build() function, returns an array of tuples
	w.println("\t@SuppressWarnings(\"unchecked\")");
	w.print("\tpublic Tuple" + numFields);
	printGenericsString(w, numFields);
	w.println("[] build(){");
	w.println("\t\treturn tuples.toArray(new Tuple" + numFields + "[tuples.size()]);");
	w.println("\t}");

	// foot
	w.println("}");
	}

	private static final String HEADER =
	"/*\n"
	+ " * Licensed to the Apache Software Foundation (ASF) under one\n"
	+ " * or more contributor license agreements. See the NOTICE file\n"
	+ " * distributed with this work for additional information\n"
	+ " * regarding copyright ownership. The ASF licenses this file\n"
	+ " * to you under the Apache License, Version 2.0 (the\n"
	+ " * \"License\"); you may not use this file except in compliance\n"
	+ " * with the License. You may obtain a copy of the License at\n"
	+ " *\n"
	+ " * http://www.apache.org/licenses/LICENSE-2.0\n"
	+ " *\n"
	+ " * Unless required by applicable law or agreed to in writing, software\n"
	+ " * distributed under the License is distributed on an \"AS IS\" BASIS,\n"
	+ " * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n"
	+ " * See the License for the specific language governing permissions and\n"
	+ " * limitations under the License.\n"
	+ " */" +
	"\n" +
	"\n" +
	"// --------------------------------------------------------------\n" +
	"// THIS IS A GENERATED SOURCE FILE. DO NOT EDIT!\n" +
	"// GENERATED FROM " + TupleGenerator.class.getName() + ".\n" +
	"// --------------------------------------------------------------\n\n";
	}