countingoutputstreamtest.java

java 的io 操作类 java 的io 操作类

/*
 * 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.commons.io.output;


import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import junit.framework.TestCase;

import org.apache.commons.io.IOUtils;
import org.apache.commons.io.input.NullInputStream;


/**
 * @version $Revision: 606381 $ $Date: 2007-12-22 02:03:16 +0000 (Sat, 22 Dec 2007) $
 */

public class CountingOutputStreamTest extends TestCase {

    public CountingOutputStreamTest(String name) {
        super(name);
    }

    public void testCounting() throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        CountingOutputStream cos = new CountingOutputStream(baos);

        for(int i = 0; i < 20; i++) {
            cos.write(i);
        }
        assertByteArrayEquals("CountingOutputStream.write(int)", baos.toByteArray(), 0, 20);
        assertEquals("CountingOutputStream.getCount()", cos.getCount(), 20);

        byte[] array = new byte[10];
        for(int i = 20; i < 30; i++) {
            array[i-20] = (byte)i;
        }
        cos.write(array);
        assertByteArrayEquals("CountingOutputStream.write(byte[])", baos.toByteArray(), 0, 30);
        assertEquals("CountingOutputStream.getCount()", cos.getCount(), 30);

        for(int i = 25; i < 35; i++) {
            array[i-25] = (byte)i;
        }
        cos.write(array, 5, 5);
        assertByteArrayEquals("CountingOutputStream.write(byte[], int, int)", baos.toByteArray(), 0, 35);
        assertEquals("CountingOutputStream.getCount()", cos.getCount(), 35);

        int count = cos.resetCount();
        assertEquals("CountingOutputStream.resetCount()", count, 35);

        for(int i = 0; i < 10; i++) {
            cos.write(i);
        }
        assertByteArrayEquals("CountingOutputStream.write(int)", baos.toByteArray(), 35, 45);
        assertEquals("CountingOutputStream.getCount()", cos.getCount(), 10);

    }

    /**
     * Test for files > 2GB in size - see issue IO-84
     */
    public void testLargeFiles_IO84() throws Exception {
        long size = (long)Integer.MAX_VALUE + (long)1;

        NullInputStream mock     = new NullInputStream(size);
        OutputStream nos         = new NullOutputStream();
        CountingOutputStream cos = new CountingOutputStream(nos);

        // Test integer methods
        IOUtils.copyLarge(mock, cos);
        try {
            cos.getCount();
            fail("Expected getCount() to throw an ArithmeticException");
        } catch (ArithmeticException ae) {
            // expected result
        }
        try {
            cos.resetCount();
            fail("Expected resetCount() to throw an ArithmeticException");
        } catch (ArithmeticException ae) {
            // expected result
        }

        mock.close();

        // Test long methods
        IOUtils.copyLarge(mock, cos);
        assertEquals("getByteCount()",   size, cos.getByteCount());
        assertEquals("resetByteCount()", size, cos.resetByteCount());
    }

    private void assertByteArrayEquals(String msg, byte[] array, int start, int end) {
        for (int i = start; i < end; i++) {
            assertEquals(msg+": array[" + i + "] mismatch", array[i], i-start);
        }
    }

}