/*
* Copyright (C) 2007 The Guava Authors
*
* 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 com.google.common.io;
import static com.google.common.base.Charsets.UTF_8;
import static com.google.common.io.CharStreams.copy;
import static com.google.common.io.CharStreams.newReaderSupplier;
import com.google.common.base.Charsets;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.testing.TestLogHandler;
import java.io.ByteArrayInputStream;
import java.io.EOFException;
import java.io.FilterReader;
import java.io.FilterWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.List;
/**
* Unit test for {@link CharStreams}.
*
* @author Chris Nokleberg
*/
public class CharStreamsTest extends IoTestCase {
private static final String TEXT
= "The quick brown fox jumped over the lazy dog.";
static final InputSupplier<? extends Reader> BROKEN_READ
= CharStreams.newReaderSupplier(ByteStreamsTest.BROKEN_READ, UTF_8);
static final OutputSupplier<? extends Writer> BROKEN_WRITE
= CharStreams.newWriterSupplier(ByteStreamsTest.BROKEN_WRITE, UTF_8);
static final InputSupplier<? extends Reader> BROKEN_CLOSE_INPUT
= CharStreams.newReaderSupplier(ByteStreamsTest.BROKEN_CLOSE_INPUT, UTF_8);
static final OutputSupplier<? extends Writer> BROKEN_CLOSE_OUTPUT
= CharStreams.newWriterSupplier(ByteStreamsTest.BROKEN_CLOSE_OUTPUT, UTF_8);
static final InputSupplier<? extends Reader> BROKEN_GET_INPUT
= CharStreams.newReaderSupplier(ByteStreamsTest.BROKEN_GET_INPUT, UTF_8);
static final OutputSupplier<? extends Writer> BROKEN_GET_OUTPUT
= CharStreams.newWriterSupplier(ByteStreamsTest.BROKEN_GET_OUTPUT, UTF_8);
private static final ImmutableSet<InputSupplier<? extends Reader>> BROKEN_INPUTS =
ImmutableSet.of(BROKEN_CLOSE_INPUT, BROKEN_GET_INPUT, BROKEN_READ);
private static final ImmutableSet<OutputSupplier<? extends Writer>> BROKEN_OUTPUTS
= ImmutableSet.of(BROKEN_CLOSE_OUTPUT, BROKEN_GET_OUTPUT, BROKEN_WRITE);
public void testToString() throws IOException {
assertEquals(TEXT, CharStreams.toString(new StringReader(TEXT)));
assertEquals(TEXT,
CharStreams.toString(CharStreams.newReaderSupplier(TEXT)));
}
public void testSkipFully_blockingRead() throws IOException {
Reader reader = new NonSkippingReader("abcdef");
CharStreams.skipFully(reader, 6);
assertEquals(-1, reader.read());
}
private static class NonSkippingReader extends StringReader {
NonSkippingReader(String s) {
super(s);
}
@Override
public long skip(long n) {
return 0;
}
}
public void testReadLines_fromReadable() throws IOException {
byte[] bytes = "a\nb\nc".getBytes(Charsets.UTF_8.name());
List<String> lines = CharStreams.readLines(
new InputStreamReader(new ByteArrayInputStream(bytes), Charsets.UTF_8));
assertEquals(ImmutableList.of("a", "b", "c"), lines);
}
public void testReadLines_withLineProcessor() throws IOException {
InputSupplier<StringReader> r = CharStreams.newReaderSupplier("a\nb\nc");
// Test a LineProcessor that always returns false.
LineProcessor<Integer> alwaysFalse = new LineProcessor<Integer>() {
int seen;
@Override
public boolean processLine(String line) {
seen++;
return false;
}
@Override
public Integer getResult() {
return seen;
}
};
assertEquals("processLine was called more than once", 1,
CharStreams.readLines(r, alwaysFalse).intValue());
// Test a LineProcessor that always returns true.
LineProcessor<Integer> alwaysTrue = new LineProcessor<Integer>() {
int seen;
@Override
public boolean processLine(String line) {
seen++;
return true;
}
@Override
public Integer getResult() {
return seen;
}
};
assertEquals("processLine was not called for all the lines", 3,
CharStreams.readLines(r, alwaysTrue).intValue());
// Test a LineProcessor that is conditional.
final StringBuilder sb = new StringBuilder();
LineProcessor<Integer> conditional = new LineProcessor<Integer>() {
int seen;
@Override
public boolean processLine(String line) {
seen++;
sb.append(line);
return seen < 2;
}
@Override
public Integer getResult() {
return seen;
}
};
assertEquals(2, CharStreams.readLines(r, conditional).intValue());
assertEquals("ab", sb.toString());
}
public void testAlwaysCloses() throws IOException {
CheckCloseSupplier.Input<Reader> okRead
= newCheckReader(CharStreams.newReaderSupplier(TEXT));
CheckCloseSupplier.Output<Writer> okWrite
= newCheckWriter(new OutputSupplier<Writer>() {
@Override
public Writer getOutput() {
return new StringWriter();
}
});
CheckCloseSupplier.Input<Reader> brokenRead = newCheckReader(BROKEN_READ);
CheckCloseSupplier.Output<Writer> brokenWrite
= newCheckWriter(BROKEN_WRITE);
CharStreams.copy(okRead, okWrite);
assertTrue(okRead.areClosed());
assertTrue(okWrite.areClosed());
try {
CharStreams.copy(okRead, brokenWrite);
fail("expected exception");
} catch (Exception e) {
assertEquals("broken write", e.getMessage());
}
assertTrue(okRead.areClosed());
assertTrue(brokenWrite.areClosed());
try {
CharStreams.copy(brokenRead, okWrite);
fail("expected exception");
} catch (Exception e) {
assertEquals("broken read", e.getMessage());
}
assertTrue(brokenRead.areClosed());
assertTrue(okWrite.areClosed());
try {
CharStreams.copy(brokenRead, brokenWrite);
fail("expected exception");
} catch (Exception e) {
assertEquals("broken read", e.getMessage());
}
assertTrue(brokenRead.areClosed());
assertTrue(brokenWrite.areClosed());
assertEquals(TEXT, CharStreams.toString(okRead));
assertTrue(okRead.areClosed());
try {
CharStreams.toString(brokenRead);
fail("expected exception");
} catch (Exception e) {
assertEquals("broken read", e.getMessage());
}
assertTrue(brokenRead.areClosed());
try {
CharStreams.write("hello world", brokenWrite);
fail("expected exception");
} catch (Exception e) {
assertEquals("broken write", e.getMessage());
}
assertTrue(brokenWrite.areClosed());
}
private static int getAndResetRecords(TestLogHandler logHandler) {
int records = logHandler.getStoredLogRecords().size();
logHandler.clear();
return records;
}
private static void runFailureTest(
InputSupplier<? extends Reader> in, OutputSupplier<? extends Writer> out) {
try {
copy(in, out);
fail();
} catch (IOException expected) {
}
}
private static OutputSupplier<Writer> newStringWriterSupplier() {
return new OutputSupplier<Writer>() {
@Override public Writer getOutput() {
return new StringWriter();
}
};
}
public void testSkipFully_EOF() throws IOException {
Reader reader = new StringReader("abcde");
try {
CharStreams.skipFully(reader, 6);
fail("expected EOFException");
} catch (EOFException e) {
// expected
}
}
public void testSkipFully() throws IOException {
String testString = "abcdef";
Reader reader = new StringReader(testString);
assertEquals(testString.charAt(0), reader.read());
CharStreams.skipFully(reader, 1);
assertEquals(testString.charAt(2), reader.read());
CharStreams.skipFully(reader, 2);
assertEquals(testString.charAt(5), reader.read());
assertEquals(-1, reader.read());
}
public void testAsWriter() {
// Should wrap Appendable in a new object
Appendable plainAppendable = new StringBuilder();
Writer result = CharStreams.asWriter(plainAppendable);
assertNotSame(plainAppendable, result);
assertNotNull(result);
// A Writer should not be wrapped
Appendable secretlyAWriter = new StringWriter();
result = CharStreams.asWriter(secretlyAWriter);
assertSame(secretlyAWriter, result);
}
public void testWriteString() throws IOException {
final StringWriter sw = new StringWriter();
String expected = "foo";
CharStreams.write(expected, new OutputSupplier<Writer>() {
@Override public Writer getOutput() {
return sw;
}
});
assertEquals(expected, sw.toString());
}
public void testCopy() throws IOException {
StringBuilder builder = new StringBuilder();
long copied = CharStreams.copy(new StringReader(ASCII), builder);
assertEquals(ASCII, builder.toString());
assertEquals(ASCII.length(), copied);
StringBuilder builder2 = new StringBuilder();
copied = CharStreams.copy(new StringReader(I18N), builder2);
assertEquals(I18N, builder2.toString());
assertEquals(I18N.length(), copied);
}
/**
* Test for Guava issue 1061: http://code.google.com/p/guava-libraries/issues/detail?id=1061
*
* <p>CharStreams.copy was failing to clear its CharBuffer after each read call, which effectively
* reduced the available size of the buffer each time a call to read didn't fill up the available
* space in the buffer completely. In general this is a performance problem since the buffer size
* is permanently reduced, but with certain Reader implementations it could also cause the buffer
* size to reach 0, causing an infinite loop.
*/
public void testCopyWithReaderThatDoesNotFillBuffer() throws IOException {
// need a long enough string for the buffer to hit 0 remaining before the copy completes
String string = Strings.repeat("0123456789", 100);
StringBuilder b = new StringBuilder();
// the main assertion of this test is here... the copy will fail if the buffer size goes down
// each time it is not filled completely
long copied = CharStreams.copy(newNonBufferFillingReader(new StringReader(string)), b);
assertEquals(string, b.toString());
assertEquals(string.length(), copied);
}
private static CheckCloseSupplier.Input<Reader> newCheckReader(
InputSupplier<? extends Reader> delegate) {
return new CheckCloseSupplier.Input<Reader>(delegate) {
@Override protected Reader wrap(Reader object, final Callback callback) {
return new FilterReader(object) {
@Override public void close() throws IOException {
callback.delegateClosed();
super.close();
}
};
}
};
}
private static CheckCloseSupplier.Output<Writer> newCheckWriter(
OutputSupplier<? extends Writer> delegate) {
return new CheckCloseSupplier.Output<Writer>(delegate) {
@Override protected Writer wrap(Writer object, final Callback callback) {
return new FilterWriter(object) {
@Override public void close() throws IOException {
callback.delegateClosed();
super.close();
}
};
}
};
}
/**
* Returns a reader wrapping the given reader that only reads half of the maximum number of
* characters that it could read in read(char[], int, int).
*/
private static Reader newNonBufferFillingReader(Reader reader) {
return new FilterReader(reader) {
@Override
public int read(char[] cbuf, int off, int len) throws IOException {
// if a buffer isn't being cleared correctly, this method will eventually start being called
// with a len of 0 forever
if (len <= 0) {
fail("read called with a len of " + len);
}
// read fewer than the max number of chars to read
// shouldn't be a problem unless the buffer is shrinking each call
return in.read(cbuf, off, Math.max(len - 1024, 0));
}
};
}
}