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      1 /*
      2  * Copyright (C) 2007 The Guava Authors
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.common.io;
     18 
     19 import com.google.common.primitives.Bytes;
     20 
     21 import junit.framework.TestCase;
     22 
     23 import java.io.ByteArrayInputStream;
     24 import java.io.ByteArrayOutputStream;
     25 import java.io.DataInput;
     26 import java.io.DataOutputStream;
     27 import java.io.EOFException;
     28 import java.io.IOException;
     29 
     30 /**
     31  * Test class for {@link LittleEndianDataInputStream}.
     32  *
     33  * @author Chris Nokleberg
     34  */
     35 public class LittleEndianDataInputStreamTest extends TestCase {
     36 
     37   private byte[] data;
     38 
     39   @Override
     40   protected void setUp() throws Exception {
     41     super.setUp();
     42 
     43     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     44     DataOutputStream out = new DataOutputStream(baos);
     45 
     46     initializeData(out);
     47 
     48     data = baos.toByteArray();
     49   }
     50 
     51   private void initializeData(DataOutputStream out) throws IOException {
     52     /* Write out various test values NORMALLY */
     53     out.write(new byte[] { -100, 100 });
     54     out.writeBoolean(true);
     55     out.writeBoolean(false);
     56     out.writeByte(100);
     57     out.writeByte(-100);
     58     out.writeByte((byte) 200);
     59     out.writeChar('a');
     60     out.writeShort((short) -30000);
     61     out.writeShort((short) 50000);
     62     out.writeInt(0xCAFEBABE);
     63     out.writeLong(0xDEADBEEFCAFEBABEL);
     64     out.writeUTF("Herby Derby");
     65     out.writeFloat(Float.intBitsToFloat(0xCAFEBABE));
     66     out.writeDouble(Double.longBitsToDouble(0xDEADBEEFCAFEBABEL));
     67   }
     68 
     69   public void testReadFully() throws IOException {
     70     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
     71     byte[] b = new byte[data.length];
     72     in.readFully(b);
     73     assertEquals(Bytes.asList(data), Bytes.asList(b));
     74   }
     75 
     76   public void testReadUnsignedByte_eof() throws IOException {
     77     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(new byte[0]));
     78     try {
     79       in.readUnsignedByte();
     80       fail();
     81     } catch (EOFException expected) {
     82     }
     83   }
     84 
     85   public void testReadUnsignedShort_eof() throws IOException {
     86     byte[] buf = {23};
     87     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(buf));
     88     try {
     89       in.readUnsignedShort();
     90       fail();
     91     } catch (EOFException expected) {}
     92   }
     93 
     94   public void testReadLine() throws IOException {
     95     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
     96     try {
     97       in.readLine();
     98       fail();
     99     } catch (UnsupportedOperationException expected) {
    100       assertEquals("readLine is not supported", expected.getMessage());
    101     }
    102   }
    103 
    104   public void testReadLittleEndian() throws IOException {
    105     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
    106 
    107     /* Read in various values in LITTLE ENDIAN FORMAT */
    108     byte[] b = new byte[2];
    109     in.readFully(b);
    110     assertEquals(-100, b[0]);
    111     assertEquals(100, b[1]);
    112     assertEquals(true, in.readBoolean());
    113     assertEquals(false, in.readBoolean());
    114     assertEquals(100, in.readByte());
    115     assertEquals(-100, in.readByte());
    116     assertEquals(200, in.readUnsignedByte());
    117     assertEquals('\u6100', in.readChar());
    118     assertEquals(-12150, in.readShort());
    119     assertEquals(20675, in.readUnsignedShort());
    120     assertEquals(0xBEBAFECA, in.readInt());
    121     assertEquals(0xBEBAFECAEFBEADDEL, in.readLong());
    122     assertEquals("Herby Derby", in.readUTF());
    123     assertEquals(0xBEBAFECA, Float.floatToIntBits(in.readFloat()));
    124     assertEquals(0xBEBAFECAEFBEADDEL, Double.doubleToLongBits(in.readDouble()));
    125   }
    126 
    127   public void testSkipBytes() throws IOException {
    128     ByteArrayOutputStream baos = new ByteArrayOutputStream();
    129     DataOutputStream out = new DataOutputStream(baos);
    130 
    131     /* Write out various test values NORMALLY */
    132     out.write(new byte[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}); // 10 bytes of junk to skip
    133     initializeData(out);
    134 
    135     byte[] data = baos.toByteArray();
    136 
    137     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
    138     int bytesSkipped = 0;
    139     while (bytesSkipped < 10) {
    140       bytesSkipped += in.skipBytes(10 - bytesSkipped);
    141     }
    142 
    143     /* Read in various values in LITTLE ENDIAN FORMAT */
    144     byte[] b = new byte[2];
    145     in.readFully(b);
    146     assertEquals(-100, b[0]);
    147     assertEquals(100, b[1]);
    148     assertTrue(in.readBoolean());
    149     assertFalse(in.readBoolean());
    150   }
    151 }
    152