Enhance javadoc and coverage for IOUtils

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1887801 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Dominik Stadler 2021-03-19 09:40:05 +00:00
parent 2ceb5ff553
commit 82bf04669f
2 changed files with 223 additions and 19 deletions

View File

@ -232,6 +232,13 @@ public final class IOUtils {
/**
* Helper method, just calls <tt>readFully(in, b, 0, b.length)</tt>
*
* @param in the stream from which the data is read.
* @param b the buffer into which the data is read.
*
* @return the number of bytes read or -1 if no bytes were read
*
* @throws IOException if reading from the stream fails
*/
public static int readFully(InputStream in, byte[] b) throws IOException {
return readFully(in, b, 0, b.length);
@ -250,6 +257,10 @@ public final class IOUtils {
* @param b the buffer into which the data is read.
* @param off the start offset in array <tt>b</tt> at which the data is written.
* @param len the maximum number of bytes to read.
*
* @return the number of bytes read or -1 if no bytes were read
*
* @throws IOException if reading from the stream fails
*/
public static int readFully(InputStream in, byte[] b, int off, int len) throws IOException {
int total = 0;
@ -275,6 +286,13 @@ public final class IOUtils {
* number of bytes read. If the end of the file isn't reached before the
* buffer has no more remaining capacity, will return the number of bytes
* that were read.
*
* @param channel The byte-channel to read data from
* @param b the buffer into which the data is read.
*
* @return the number of bytes read or -1 if no bytes were read
*
* @throws IOException if reading from the stream fails
*/
public static int readFully(ReadableByteChannel channel, ByteBuffer b) throws IOException {
int total = 0;

View File

@ -26,6 +26,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
@ -34,6 +35,7 @@ import java.io.InputStream;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.nio.charset.StandardCharsets;
import java.util.Random;
@ -42,29 +44,25 @@ import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
/**
* Class to test IOUtils
*/
final class TestIOUtils {
private static File TMP;
private static final long LENGTH = 300+new Random().nextInt(9000);
private static final long LENGTH = 300 + new Random().nextInt(9000);
@BeforeAll
public static void setUp() throws IOException {
TMP = File.createTempFile("poi-ioutils-", "");
OutputStream os = new FileOutputStream(TMP);
for (int i = 0; i < LENGTH; i++) {
os.write(0x01);
try (OutputStream os = new FileOutputStream(TMP)) {
for (int i = 0; i < LENGTH; i++) {
os.write(0x01);
}
}
os.flush();
os.close();
}
@AfterAll
public static void tearDown() {
if (TMP != null) assertTrue(TMP.delete());
if (TMP != null) {
assertTrue(TMP.delete());
}
}
private static InputStream data123() {
@ -163,7 +161,7 @@ final class TestIOUtils {
void testSkipFullyByteArray() throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try (InputStream is = new FileInputStream(TMP)) {
IOUtils.copy(is, bos);
assertEquals(LENGTH, IOUtils.copy(is, bos));
long skipped = IOUtils.skipFully(new ByteArrayInputStream(bos.toByteArray()), 20000L);
assertEquals(LENGTH, skipped);
}
@ -173,12 +171,41 @@ final class TestIOUtils {
void testSkipFullyByteArrayGtIntMax() throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try (InputStream is = new FileInputStream(TMP)) {
IOUtils.copy(is, bos);
assertEquals(LENGTH, IOUtils.copy(is, bos));
long skipped = IOUtils.skipFully(new ByteArrayInputStream(bos.toByteArray()), Integer.MAX_VALUE + 20000L);
assertEquals(LENGTH, skipped);
}
}
@Test
void testCopyToFile() throws IOException {
File dest = File.createTempFile("poi-ioutils-", "");
try {
try (InputStream is = new FileInputStream(TMP)) {
assertEquals(LENGTH, IOUtils.copy(is, dest));
}
try (FileInputStream strOrig = new FileInputStream(TMP);
FileInputStream strDest = new FileInputStream(dest)) {
byte[] bytesOrig = new byte[(int)LENGTH];
byte[] bytesDest = new byte[(int)LENGTH];
IOUtils.readFully(strOrig, bytesOrig);
IOUtils.readFully(strDest, bytesDest);
assertArrayEquals(bytesOrig, bytesDest);
}
} finally {
assertTrue(dest.delete());
}
}
@Test
void testCopyToInvalidFile() throws IOException {
try (InputStream is = new FileInputStream(TMP)) {
assertThrows(RuntimeException.class,
() -> IOUtils.copy(is, new File("/notexisting/directory/structure")));
}
}
@Test
void testSkipFullyBug61294() throws IOException {
long skipped = IOUtils.skipFully(new ByteArrayInputStream(new byte[0]), 1);
@ -292,7 +319,7 @@ final class TestIOUtils {
}
@Test
void testSetMaxOverrideOverLimitWithLength() throws IOException {
void testSetMaxOverrideOverLimitWithLength() {
IOUtils.setByteArrayMaxOverride(2);
try {
ByteArrayInputStream stream = new ByteArrayInputStream("abc".getBytes(StandardCharsets.UTF_8));
@ -324,31 +351,92 @@ final class TestIOUtils {
@Test
void testReadFully() throws IOException {
byte[] bytes = new byte[2];
IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes, 0, 2);
assertEquals(2, IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes, 0, 2));
assertArrayEquals(new byte[] {1,2}, bytes);
}
@Test
void testReadFullyEOF() throws IOException {
byte[] bytes = new byte[2];
assertEquals(2, IOUtils.readFully(new NullInputStream(2), bytes, 0, 4));
assertArrayEquals(new byte[] {0,0}, bytes);
}
@Test
void testReadFullyEOFZero() throws IOException {
byte[] bytes = new byte[2];
assertEquals(-1, IOUtils.readFully(new NullInputStream(0), bytes, 0, 4));
assertArrayEquals(new byte[] {0,0}, bytes);
}
@Test
void testReadFullySimple() throws IOException {
byte[] bytes = new byte[2];
IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes);
assertEquals(2, IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes));
assertArrayEquals(new byte[] {1,2}, bytes);
}
@Test
void testReadFullyOffset() throws IOException {
byte[] bytes = new byte[3];
IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes, 1, 2);
assertEquals(2, IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes, 1, 2));
assertArrayEquals(new byte[] {0, 1,2}, bytes);
}
@Test
void testReadFullyAtLength() throws IOException {
byte[] bytes = new byte[3];
IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes, 0, 3);
assertEquals(3, IOUtils.readFully(new ByteArrayInputStream(new byte[] {1, 2, 3}), bytes, 0, 3));
assertArrayEquals(new byte[] {1,2, 3}, bytes);
}
@Test
void testReadFullyChannel() throws IOException {
ByteBuffer bytes = ByteBuffer.allocate(2);
assertEquals(2, IOUtils.readFully(new SimpleByteChannel(new byte[]{1, 2, 3}), bytes));
assertArrayEquals(new byte[] {1,2}, bytes.array());
assertEquals(2, bytes.position());
}
@Test
void testReadFullyChannelEOF() throws IOException {
ByteBuffer bytes = ByteBuffer.allocate(2);
assertEquals(-1, IOUtils.readFully(new EOFByteChannel(false), bytes));
assertArrayEquals(new byte[] {0,0}, bytes.array());
assertEquals(0, bytes.position());
}
@Test
void testReadFullyChannelEOFException() {
ByteBuffer bytes = ByteBuffer.allocate(2);
assertThrows(IOException.class,
() -> IOUtils.readFully(new EOFByteChannel(true), bytes));
}
@Test
void testReadFullyChannelSimple() throws IOException {
ByteBuffer bytes = ByteBuffer.allocate(2);
assertEquals(2, IOUtils.readFully(new SimpleByteChannel(new byte[] {1, 2, 3}), bytes));
assertArrayEquals(new byte[] {1,2}, bytes.array());
assertEquals(2, bytes.position());
}
@Test
public void testChecksum() {
assertEquals(0L, IOUtils.calculateChecksum(new byte[0]));
assertEquals(3057449933L, IOUtils.calculateChecksum(new byte[] { 1, 2, 3, 4}));
}
@Test
public void testChecksumStream() throws IOException {
assertEquals(0L, IOUtils.calculateChecksum(new NullInputStream(0)));
assertEquals(0L, IOUtils.calculateChecksum(new NullInputStream(1)));
assertEquals(3057449933L, IOUtils.calculateChecksum(new ByteArrayInputStream(new byte[] { 1, 2, 3, 4})));
assertThrows(EOFException.class,
() -> IOUtils.calculateChecksum(new NullInputStream(1, true)));
}
/**
* This returns 0 for the first call to skip and then reads
* as requested. This tests that the fallback to read() works.
@ -386,4 +474,102 @@ final class TestIOUtils {
return 100000;
}
}
private static class EOFByteChannel implements ReadableByteChannel {
private final boolean throwException;
public EOFByteChannel(boolean throwException) {
this.throwException = throwException;
}
@Override
public int read(ByteBuffer dst) throws IOException {
if (throwException) {
throw new IOException("EOF");
}
return -1;
}
@Override
public boolean isOpen() {
return false;
}
@Override
public void close() throws IOException {
}
}
private static class SimpleByteChannel extends InputStream implements ReadableByteChannel {
private final byte[] bytes;
public SimpleByteChannel(byte[] bytes) {
this.bytes = bytes;
}
@Override
public int read() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public int read(ByteBuffer dst) throws IOException {
int toRead = Math.min(bytes.length, dst.capacity());
dst.put(bytes, 0, toRead);
return toRead;
}
@Override
public boolean isOpen() {
return false;
}
}
public class NullInputStream extends InputStream {
private final int bytes;
private final boolean exception;
private int position;
public NullInputStream(int bytes) {
this(bytes, false);
}
public NullInputStream(int bytes, boolean exception) {
this.bytes = bytes;
this.exception = exception;
}
@Override
public int read() throws IOException {
if (position >= bytes) {
return handleReturn();
}
position++;
return 0;
}
private int handleReturn() throws EOFException {
if (exception) {
throw new EOFException();
} else {
return -1;
}
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
int toRead = Math.min(b.length, len);
if (toRead > (bytes - position)) {
return handleReturn();
}
toRead = Math.min(toRead, (bytes - position));
position += toRead;
return toRead;
}
}
}