import org.apache.http.nio.util.HeapByteBufferAllocator; //导入依赖的package包/类
@Override
protected void onEntityEnclosed(final HttpEntity entity,
        final ContentType contentType) throws IOException {
    long len = entity.getContentLength();
    if (len > Integer.MAX_VALUE) {
        throw new ContentTooLongException("Entity content is too long: "
                + len);
    }
    if (len < 0) {
        len = BUFFER_SIZE;
    }
    this.buf = new SimpleInputBuffer((int) len,
            new HeapByteBufferAllocator());
    this.httpResponse.setEntity(new ContentBufferEntity(entity, this.buf));
}
 

import org.apache.http.nio.util.HeapByteBufferAllocator; //导入依赖的package包/类
@Override
protected void onEntityEnclosed(final HttpEntity entity, final ContentType contentType) throws IOException {
    long len = entity.getContentLength();
    if (len > Integer.MAX_VALUE) {
        throw new ContentTooLongException("Entity content is too long: " + len);
    }
    if (len < 0) {
        len = 4096;
    }
    this.buf = new SimpleInputBuffer((int) len, new HeapByteBufferAllocator());
    this.response.setEntity(new ContentBufferEntity(entity, this.buf));
}
 

import org.apache.http.nio.util.HeapByteBufferAllocator; //导入依赖的package包/类
protected ExecCallbackAsyncREST<HttpResponse> buildAsyncClient(RESTPool pool) throws IOException {
    SSLContext sslContext;
    try {
        sslContext = SSLContext.getDefault();
    } catch (NoSuchAlgorithmException e) {
        throw new IOException(e);
    }

    Registry<SchemeIOSessionStrategy> socketRegistry = RegistryBuilder.<SchemeIOSessionStrategy>create()
            .register("http", NoopIOSessionStrategy.INSTANCE)
            .register("https", new SSLIOSessionStrategy(sslContext, NoopHostnameVerifier.INSTANCE))
            .build();

    IOReactorConfig socketConfig = IOReactorConfig.custom()
            .setIoThreadCount(pool.getReactorThreadCount())
            .setSoTimeout(new Long(pool.getSocketTimeout()).intValue())
            .setTcpNoDelay(true)
            .setSoKeepAlive(true)
            .setSelectInterval(REACTOR_SELECT_INTERVAL)
            .build();

    ConnectionConfig connectionConfig = ConnectionConfig.custom()
            .setCharset(StandardCharsets.UTF_8)
            .setMalformedInputAction(CodingErrorAction.IGNORE)
            .setUnmappableInputAction(CodingErrorAction.IGNORE)
            .build();

    RequestConfig requestConfig = RequestConfig.custom()
            .setConnectionRequestTimeout(new Long(pool.getMaxPoolWait()).intValue())
            .setConnectTimeout(new Long(pool.getConnectionTimeout()).intValue())
            .setExpectContinueEnabled(pool.expectContinue())
            .setRedirectsEnabled(false)
            .setStaleConnectionCheckEnabled(pool.getValidationOnInactivity() >= 0)
            .build();

    NHttpConnectionFactory<ManagedNHttpClientConnection> connFactory = new ManagedNHttpClientConnectionFactory(
            new org.apache.http.impl.nio.codecs.DefaultHttpRequestWriterFactory(),
            new org.apache.http.impl.nio.codecs.DefaultHttpResponseParserFactory(),
            HeapByteBufferAllocator.INSTANCE
    );

    //TODO set validateAfterInactivity when supported
    PoolingNHttpClientConnectionManager ccm = new PoolingNHttpClientConnectionManager(
            new DefaultConnectingIOReactor(socketConfig),
            connFactory,
            socketRegistry,
            new SystemDefaultDnsResolver()
    );

    ccm.setMaxTotal(pool.getMaxTotal());
    ccm.setDefaultMaxPerRoute(pool.getMaxPerRoute());
    ccm.setDefaultConnectionConfig(connectionConfig);

    HttpAsyncClientBuilder builder = HttpAsyncClients.custom()
            .setConnectionManager(ccm)
            .setDefaultRequestConfig(requestConfig)
            .setKeepAliveStrategy(DefaultConnectionKeepAliveStrategy.INSTANCE)
            .disableCookieManagement();

    IdleAsyncConnectionEvictor evictor = new IdleAsyncConnectionEvictor(ccm, pool.getEvictorSleep(), TimeUnit.MILLISECONDS, pool.getMaxIdleTime(), TimeUnit.MILLISECONDS);

    addProxy(pool, builder);

    handleRedirects(pool, builder);

    CloseableHttpAsyncClient servClient = builder.build();

    servClient.start();

    HTTPCClientMonitor monitor = pool.hasConnectionMetrics() ? new HTTPCAsyncClientMonitor(pool.getName(), ccm) : null;

    return new HTTPCAsyncClient(servClient, evictor, monitor);
}
 

import org.apache.http.nio.util.HeapByteBufferAllocator; //导入依赖的package包/类
/**
 * Returns the instance of {@link ByteBufferAllocator} to use for content buffering.
 * Allows to plug in any {@link ByteBufferAllocator} implementation.
 */
protected ByteBufferAllocator getByteBufferAllocator() {
    return HeapByteBufferAllocator.INSTANCE;
}