org.springframework.boot.devtools.tunnel.payload.HttpTunnelPayload.java Source code

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Here is the source code for org.springframework.boot.devtools.tunnel.payload.HttpTunnelPayload.java

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/*
 * Copyright 2012-2019 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.tunnel.payload;

import java.io.IOException;
import java.io.InterruptedIOException;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

/**
 * Encapsulates a payload data sent via a HTTP tunnel.
 *
 * @author Phillip Webb
 * @since 1.3.0
 */
public class HttpTunnelPayload {

    private static final String SEQ_HEADER = "x-seq";

    private static final int BUFFER_SIZE = 1024 * 100;

    protected static final char[] HEX_CHARS = "0123456789ABCDEF".toCharArray();

    private static final Log logger = LogFactory.getLog(HttpTunnelPayload.class);

    private final long sequence;

    private final ByteBuffer data;

    /**
     * Create a new {@link HttpTunnelPayload} instance.
     * @param sequence the sequence number of the payload
     * @param data the payload data
     */
    public HttpTunnelPayload(long sequence, ByteBuffer data) {
        Assert.isTrue(sequence > 0, "Sequence must be positive");
        Assert.notNull(data, "Data must not be null");
        this.sequence = sequence;
        this.data = data;
    }

    /**
     * Return the sequence number of the payload.
     * @return the sequence
     */
    public long getSequence() {
        return this.sequence;
    }

    /**
     * Assign this payload to the given {@link HttpOutputMessage}.
     * @param message the message to assign this payload to
     * @throws IOException in case of I/O errors
     */
    public void assignTo(HttpOutputMessage message) throws IOException {
        Assert.notNull(message, "Message must not be null");
        HttpHeaders headers = message.getHeaders();
        headers.setContentLength(this.data.remaining());
        headers.add(SEQ_HEADER, Long.toString(getSequence()));
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        WritableByteChannel body = Channels.newChannel(message.getBody());
        while (this.data.hasRemaining()) {
            body.write(this.data);
        }
        body.close();
    }

    /**
     * Write the content of this payload to the given target channel.
     * @param channel the channel to write to
     * @throws IOException in case of I/O errors
     */
    public void writeTo(WritableByteChannel channel) throws IOException {
        Assert.notNull(channel, "Channel must not be null");
        while (this.data.hasRemaining()) {
            channel.write(this.data);
        }
    }

    /**
     * Return the {@link HttpTunnelPayload} for the given message or {@code null} if there
     * is no payload.
     * @param message the HTTP message
     * @return the payload or {@code null}
     * @throws IOException in case of I/O errors
     */
    public static HttpTunnelPayload get(HttpInputMessage message) throws IOException {
        long length = message.getHeaders().getContentLength();
        if (length <= 0) {
            return null;
        }
        String seqHeader = message.getHeaders().getFirst(SEQ_HEADER);
        Assert.state(StringUtils.hasLength(seqHeader), "Missing sequence header");
        ReadableByteChannel body = Channels.newChannel(message.getBody());
        ByteBuffer payload = ByteBuffer.allocate((int) length);
        while (payload.hasRemaining()) {
            body.read(payload);
        }
        body.close();
        payload.flip();
        return new HttpTunnelPayload(Long.valueOf(seqHeader), payload);
    }

    /**
     * Return the payload data for the given source {@link ReadableByteChannel} or null if
     * the channel timed out whilst reading.
     * @param channel the source channel
     * @return payload data or {@code null}
     * @throws IOException in case of I/O errors
     */
    public static ByteBuffer getPayloadData(ReadableByteChannel channel) throws IOException {
        ByteBuffer buffer = ByteBuffer.allocate(BUFFER_SIZE);
        try {
            int amountRead = channel.read(buffer);
            Assert.state(amountRead != -1, "Target server connection closed");
            buffer.flip();
            return buffer;
        } catch (InterruptedIOException ex) {
            return null;
        }
    }

    /**
     * Log incoming payload information at trace level to aid diagnostics.
     */
    public void logIncoming() {
        log("< ");
    }

    /**
     * Log incoming payload information at trace level to aid diagnostics.
     */
    public void logOutgoing() {
        log("> ");
    }

    private void log(String prefix) {
        if (logger.isTraceEnabled()) {
            logger.trace(prefix + toHexString());
        }
    }

    /**
     * Return the payload as a hexadecimal string.
     * @return the payload as a hex string
     */
    public String toHexString() {
        byte[] bytes = this.data.array();
        char[] hex = new char[this.data.remaining() * 2];
        for (int i = this.data.position(); i < this.data.remaining(); i++) {
            int b = bytes[i] & 0xFF;
            hex[i * 2] = HEX_CHARS[b >>> 4];
            hex[i * 2 + 1] = HEX_CHARS[b & 0x0F];
        }
        return new String(hex);
    }

}