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/*
* Copyright 2012-2021 the original author or 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
*
* https://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.springframework.boot.devtools.livereload;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* {@link InputStream} for a server connection.
*
* @author Phillip Webb
*/
class ConnectionInputStream extends FilterInputStream {
private static final String HEADER_END = "\r\n\r\n";
private static final int BUFFER_SIZE = 4096;
ConnectionInputStream(InputStream in) {
super(in);
}
/**
* Read the HTTP header from the {@link InputStream}. Note: This method doesn't expect
* any HTTP content after the header since the initial request is usually just a
* WebSocket upgrade.
* @return the HTTP header
* @throws IOException in case of I/O errors
*/
String readHeader() throws IOException {
byte[] buffer = new byte[BUFFER_SIZE];
StringBuilder content = new StringBuilder(BUFFER_SIZE);
while (content.indexOf(HEADER_END) == -1) {
int amountRead = checkedRead(buffer, 0, BUFFER_SIZE);
content.append(new String(buffer, 0, amountRead));
}
return content.substring(0, content.indexOf(HEADER_END));
}
/**
* Repeatedly read the underlying {@link InputStream} until the requested number of
* bytes have been loaded.
* @param buffer the destination buffer
* @param offset the buffer offset
* @param length the amount of data to read
* @throws IOException in case of I/O errors
*/
void readFully(byte[] buffer, int offset, int length) throws IOException {
while (length > 0) {
int amountRead = checkedRead(buffer, offset, length);
offset += amountRead;
length -= amountRead;
}
}
/**
* Read a single byte from the stream (checking that the end of the stream hasn't been
* reached).
* @return the content
* @throws IOException in case of I/O errors
*/
int checkedRead() throws IOException {
int b = read();
if (b == -1) {
throw new IOException("End of stream");
}
return (b & 0xff);
}
/**
* Read a number of bytes from the stream (checking that the end of the stream hasn't
* been reached).
* @param buffer the destination buffer
* @param offset the buffer offset
* @param length the length to read
* @return the amount of data read
* @throws IOException in case of I/O errors
*/
int checkedRead(byte[] buffer, int offset, int length) throws IOException {
int amountRead = read(buffer, offset, length);
if (amountRead == -1) {
throw new IOException("End of stream");
}
return amountRead;
}
}