96 lines
2.1 KiB
Java
96 lines
2.1 KiB
Java
|
/*
|
||
|
|
* Copyright (C) 2008 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 java.io.IOException;
|
||
|
|
import java.io.Reader;
|
||
|
|
import java.util.Iterator;
|
||
|
|
|
||
|
|
import javax.annotation.Nullable;
|
||
|
|
|
||
|
|
import com.google.common.base.Preconditions;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* A {@link Reader} that concatenates multiple readers.
|
||
|
|
*
|
||
|
|
* @author Bin Zhu
|
||
|
|
* @since 1.0
|
||
|
|
*/
|
||
|
|
class MultiReader extends Reader {
|
||
|
|
private final Iterator<? extends CharSource> it;
|
||
|
|
private Reader current;
|
||
|
|
|
||
|
|
MultiReader(Iterator<? extends CharSource> readers) throws IOException {
|
||
|
|
this.it = readers;
|
||
|
|
advance();
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Closes the current reader and opens the next one, if any.
|
||
|
|
*/
|
||
|
|
private void advance() throws IOException {
|
||
|
|
close();
|
||
|
|
if (it.hasNext()) {
|
||
|
|
current = it.next().openStream();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public int read(@Nullable char cbuf[], int off, int len) throws IOException {
|
||
|
|
if (current == null) {
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
int result = current.read(cbuf, off, len);
|
||
|
|
if (result == -1) {
|
||
|
|
advance();
|
||
|
|
return read(cbuf, off, len);
|
||
|
|
}
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public long skip(long n) throws IOException {
|
||
|
|
Preconditions.checkArgument(n >= 0, "n is negative");
|
||
|
|
if (n > 0) {
|
||
|
|
while (current != null) {
|
||
|
|
long result = current.skip(n);
|
||
|
|
if (result > 0) {
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
advance();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public boolean ready() throws IOException {
|
||
|
|
return (current != null) && current.ready();
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public void close() throws IOException {
|
||
|
|
if (current != null) {
|
||
|
|
try {
|
||
|
|
current.close();
|
||
|
|
} finally {
|
||
|
|
current = null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|