Android example source code file (ZipStreamTest.java)

This example Android source code file (ZipStreamTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, bytearrayinputstream, bytearrayoutputstream, io, ioexception, largetest, test, testcase, this, zip, zipentry, zipinputstream, zipoutputstream, zipstreamtest

The ZipStreamTest.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * 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.
 */

package android.core;

import junit.framework.TestCase;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
import android.test.suitebuilder.annotation.LargeTest;

/**
 * Basic tests for ZipStream
 */
public class ZipStreamTest extends TestCase {

    @LargeTest
    public void testZipStream() throws Exception {
        ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
        createCompressedZip(bytesOut);

        byte[] zipData = bytesOut.toByteArray();

        /*
        FileOutputStream outFile = new FileOutputStream("/tmp/foo.zip");
        outFile.write(zipData, 0, zipData.length);
        outFile.close();
        */

        /*
        FileInputStream inFile = new FileInputStream("/tmp/foo.zip");
        int inputLength = inFile.available();
        zipData = new byte[inputLength];
        if (inFile.read(zipData) != inputLength)
            throw new RuntimeException();
        inFile.close();
        */

        ByteArrayInputStream bytesIn = new ByteArrayInputStream(zipData);
        scanZip(bytesIn);

        bytesOut = new ByteArrayOutputStream();
        createUncompressedZip(bytesOut);

        zipData = bytesOut.toByteArray();

        bytesIn = new ByteArrayInputStream(zipData);
        scanZip(bytesIn);
    }

    /*
     * stepStep == 0 --> >99% compression
     * stepStep == 1 --> ~30% compression
     * stepStep == 2 --> no compression
     */
    private static byte[] makeSampleFile(int stepStep) throws IOException {
        byte[] sample = new byte[128 * 1024];
        byte val, step;
        int i, j, offset;

        val = 0;
        step = 1;
        offset = 0;
        for (i = 0; i < (128 * 1024) / 256; i++) {
            for (j = 0; j < 256; j++) {
                sample[offset++] = val;
                val += step;
            }

            step += stepStep;
        }

        return sample;
    }

    private static void createCompressedZip(ByteArrayOutputStream bytesOut) throws IOException {
        ZipOutputStream out = new ZipOutputStream(bytesOut);
        try {
            int i;

            for (i = 0; i < 3; i++) {
                byte[] input = makeSampleFile(i);
                ZipEntry newEntry = new ZipEntry("file-" + i);

                if (i != 1)
                    newEntry.setComment("this is file " + i);
                out.putNextEntry(newEntry);
                out.write(input, 0, input.length);
                out.closeEntry();
            }

            out.setComment("This is a lovely compressed archive!");
        } finally {
            out.close();
        }
    }

    private static void createUncompressedZip(ByteArrayOutputStream bytesOut) throws IOException {
        ZipOutputStream out = new ZipOutputStream(bytesOut);
        try {
            long[] crcs = {0x205fbff3, 0x906fae57L, 0x2c235131};
            int i;

            for (i = 0; i < 3; i++) {
                byte[] input = makeSampleFile(i);
                ZipEntry newEntry = new ZipEntry("file-" + i);

                if (i != 1)
                    newEntry.setComment("this is file " + i);
                newEntry.setMethod(ZipEntry.STORED);
                newEntry.setSize(128 * 1024);
                newEntry.setCrc(crcs[i]);
                out.putNextEntry(newEntry);
                out.write(input, 0, input.length);
                out.closeEntry();
            }

            out.setComment("This is a lovely, but uncompressed, archive!");
        } finally {
            out.close();
        }
    }

    private static void scanZip(ByteArrayInputStream bytesIn) throws IOException {
        ZipInputStream in = new ZipInputStream(bytesIn);
        try {
            int i;

            for (i = 0; i < 3; i++) {
                ZipEntry entry = in.getNextEntry();
                ByteArrayOutputStream contents = new ByteArrayOutputStream();
                byte[] buf = new byte[4096];
                int len, totalLen = 0;

                while ((len = in.read(buf)) > 0) {
                    contents.write(buf, 0, len);
                    totalLen += len;
                }

                assertEquals(128 * 1024, totalLen);

//                System.out.println("ZipStreamTest: name='" + entry.getName()
//                        + "', zero=" + contents.toByteArray()[0]
//                        + ", tfs=" + contents.toByteArray()[257]
//                        + ", crc=" + Long.toHexString(entry.getCrc()));
            }

            assertNull("should only be three entries", in.getNextEntry());
        } finally {
            in.close();
        }
    }
}