如何在Java Servlet内以分块响应的形式发送Http预告片页脚？

如何在Java Servlet内以分块响应的形式发送Http预告片/页脚？

我最终为此编写了一个简单的单线程Web服务器。原来这很容易。服务器非常简单。虽然代码有点粗糙，但是主要思想就在那里。

它执行的 *** 作是将文件内容作为第一个块发送，并将文件的校验和作为页脚发送。

import java.io.BufferedReader;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.ServerSocket;import java.net.Socket;import org.apache.commons.prec.digest.DigestUtils;import org.apache.commons.io.IOUtils;import org.apache.log4j.Logger;public class ChunkedResponseServer implements Runnable {  private static final Logger LOGGER = Logger.getLogger(ChunkedResponseServer.class);  // Space ' '  static final byte SP = 32;  // Tab ' '  static final byte HT = 9;  // Carriage return  static final byte CR = 13;  // Line feed character  static final byte LF = 10;  final int port;  private volatile boolean cancelled = false;  public ChunkedResponseServer(int port) {    LOGGER.info("Chunked response server running on port " + port);    this.port = port;  }  @Override  public void run() {    ServerSocket serverSocket = null;    try {      serverSocket = new ServerSocket(port);      while (!cancelled) {        final Socket connectionSocket = serverSocket.accept();        handle(connectionSocket);      }    } catch (final IOException e) {      throw new RuntimeException(e);    }  }  public void cancel() {    LOGGER.info("Shutting down Chunked response Server");    cancelled = true;  }  private void handle(Socket socket) throws IOException {    BufferedReader input = null;    DataOutputStream output = null;    try {      input = new BufferedReader(new InputStreamReader(socket.getInputStream()));      output = new DataOutputStream(socket.getOutputStream());      addHeaders(output);      addCRLR(output);      final String filename = readFilename(input);      final byte[] content = readContent(filename);      addContentAsChunk(output, content);      final String checksum = DigestUtils.md5Hex(content);      addLastChunkAndChecksumFooter(output, checksum);      addCRLR(output);    } finally {      IOUtils.closeQuietly(input);      IOUtils.closeQuietly(output);    }  }  private void addLastChunkAndChecksumFooter(DataOutputStream output, String checksum) throws IOException {    output.writeBytes("0");    addCRLR(output);    output.writeBytes("checksum: " + checksum);    addCRLR(output);  }  private void addContentAsChunk(DataOutputStream output, byte[] content) throws IOException {    output.writeBytes(Integer.toHexString(content.length));    addCRLR(output);    output.write(content);    addCRLR(output);  }  private void addCRLR(DataOutputStream output) throws IOException {    output.writeByte(CR);    output.writeByte(LF);  }  private void addHeaders(DataOutputStream output) throws IOException {    output.writeBytes("HTTP/1.1 200 OK");    addCRLR(output);    output.writeBytes("Content-type: text/plain");    addCRLR(output);    output.writeBytes("Transfer-encoding: chunked");    addCRLR(output);    output.writeBytes("Trailer: checksum");    addCRLR(output);  }  private String readFilename(BufferedReader input) throws IOException {    final String initialLine = input.readLine();    final String filePath = initialLine.split(" ")[1];    final String[] components = filePath.split("/");    return components[components.length - 1];  }  private byte[] readContent(String filename) throws IOException {    final InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(filename);    return IOUtils.toByteArray(in);  }}