flatbuffers/tests/JavaTest.java

/*
 * Copyright 2014 Google Inc. All rights reserved.
 *
 * 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.
 */

import java.io.*;
import java.nio.ByteBuffer;
import MyGame.Example.*;
import flatbuffers.FlatBufferBuilder;

class JavaTest {
    public static void main(String[] args) {

        // First, let's test reading a FlatBuffer generated by C++ code:
        // This file was generated from monsterdata_test.json

        byte[] data = null;
        File file = new File("monsterdata_test.bin");
        RandomAccessFile f = null;
        try {
            f = new RandomAccessFile(file, "r");
            data = new byte[(int)f.length()];
            f.readFully(data);
            f.close();
        } catch(java.io.IOException e) {
            System.out.println("FlatBuffers test: couldn't read file");
            return;
        }

        // Now test it:

        ByteBuffer bb = ByteBuffer.wrap(data);
        TestBuffer(bb);

        // Second, let's create a FlatBuffer from scratch in Java, and test it also.
        // We use an initial size of 1 to exercise the reallocation algorithm,
        // normally a size larger than the typical FlatBuffer you generate would be
        // better for performance.
        FlatBufferBuilder fbb = new FlatBufferBuilder(1);

        // We set up the same values as monsterdata.json:

        int str = fbb.createString("MyMonster");
        int test1 = fbb.createString("test1");
        int test2 = fbb.createString("test2");

        Monster.startInventoryVector(fbb, 5);
        for (byte i = 4; i >=0; i--) fbb.addByte(i);
        int inv = fbb.endVector();

        Monster.startMonster(fbb);
        Monster.addHp(fbb, (short)20);
        int mon2 = Monster.endMonster(fbb);

        Monster.startTest4Vector(fbb, 2);
        Test.createTest(fbb, (short)10, (byte)20);
        Test.createTest(fbb, (short)30, (byte)40);
        int test4 = fbb.endVector();

        Monster.startTestarrayofstringVector(fbb, 2);
        fbb.addOffset(test2);
        fbb.addOffset(test1);
        int testArrayOfString = fbb.endVector();

        Monster.startMonster(fbb);
        Monster.addPos(fbb, Vec3.createVec3(fbb, 1.0f, 2.0f, 3.0f, 3.0,
                                                 (byte)4, (short)5, (byte)6));
        Monster.addHp(fbb, (short)80);
        Monster.addName(fbb, str);
        Monster.addInventory(fbb, inv);
        Monster.addTestType(fbb, (byte)Any.Monster);
        Monster.addTest(fbb, mon2);
        Monster.addTest4(fbb, test4);
        Monster.addTestarrayofstring(fbb, testArrayOfString);
        int mon = Monster.endMonster(fbb);

        Monster.finishMonsterBuffer(fbb, mon);

        // Write the result to a file for debugging purposes:
        // Note that the binaries are not necessarily identical, since the JSON
        // parser may serialize in a slightly different order than the above
        // Java code. They are functionally equivalent though.

        try {
             DataOutputStream os = new DataOutputStream(new FileOutputStream(
                                           "monsterdata_java_wire.bin"));
             os.write(fbb.dataBuffer().array(), fbb.dataBuffer().position(), fbb.offset());
             os.close();
        } catch(java.io.IOException e) {
            System.out.println("FlatBuffers test: couldn't write file");
            return;
        }

        // Test it:
        TestBuffer(fbb.dataBuffer());

        // Make sure it also works with read only ByteBuffers. This is slower,
        // since creating strings incurs an additional copy
        // (see Table.__string).
        TestBuffer(fbb.dataBuffer().asReadOnlyBuffer());

        System.out.println("FlatBuffers test: completed successfully");
    }

    static void TestBuffer(ByteBuffer bb) {
        TestEq(Monster.MonsterBufferHasIdentifier(bb), true);

        Monster monster = Monster.getRootAsMonster(bb);

        TestEq(monster.hp(), (short)80);
        TestEq(monster.mana(), (short)150);  // default

        TestEq(monster.name(), "MyMonster");
        // monster.friendly() // can't access, deprecated

        Vec3 pos = monster.pos();
        TestEq(pos.x(), 1.0f);
        TestEq(pos.y(), 2.0f);
        TestEq(pos.z(), 3.0f);
        TestEq(pos.test1(), 3.0);
        TestEq(pos.test2(), (byte)4);
        Test t = pos.test3();
        TestEq(t.a(), (short)5);
        TestEq(t.b(), (byte)6);

        TestEq(monster.testType(), (byte)Any.Monster);
        Monster monster2 = new Monster();
        TestEq(monster.test(monster2) != null, true);
        TestEq(monster2.hp(), (short)20);

        TestEq(monster.inventoryLength(), 5);
        int invsum = 0;
        for (int i = 0; i < monster.inventoryLength(); i++)
            invsum += monster.inventory(i);
        TestEq(invsum, 10);

        // Alternative way of accessing a vector:
        ByteBuffer ibb = monster.inventoryAsByteBuffer();
        invsum = 0;
        while (ibb.position() < ibb.limit())
            invsum += ibb.get();
        TestEq(invsum, 10);

        Test test_0 = monster.test4(0);
        Test test_1 = monster.test4(1);
        TestEq(monster.test4Length(), 2);
        TestEq(test_0.a() + test_0.b() + test_1.a() + test_1.b(), 100);

        TestEq(monster.testarrayofstringLength(), 2);
        TestEq(monster.testarrayofstring(0),"test1");
        TestEq(monster.testarrayofstring(1),"test2");
    }

    static <T> void TestEq(T a, T b) {
        if (!a.equals(b)) {
            System.out.println("" + a.getClass().getName() + " " + b.getClass().getName());
            System.out.println("FlatBuffers test FAILED: \'" + a + "\' != \'" + b + "\'");
            assert false;
            System.exit(1);
        }
    }
}