Java Writable.write方法代碼示例

import org.apache.hadoop.io.Writable; //導入方法依賴的package包/類
/**
 * Setup response for the IPC Call.
 * 
 * @param response buffer to serialize the response into
 * @param call {@link Call} to which we are setting up the response
 * @param status {@link Status} of the IPC call
 * @param rv return value for the IPC Call, if the call was successful
 * @param errorClass error class, if the the call failed
 * @param error error message, if the call failed
 * @throws IOException
 */
private void setupResponse(ByteArrayOutputStream response, 
                           Call call, Status status, 
                           Writable rv, String errorClass, String error) 
throws IOException {
  response.reset();
  DataOutputStream out = new DataOutputStream(response);
  out.writeInt(call.id);                // write call id
  out.writeInt(status.state);           // write status

  if (status == Status.SUCCESS) {
    rv.write(out);
  } else {
    WritableUtils.writeString(out, errorClass);
    WritableUtils.writeString(out, error);
  }
  /*if (call.connection.useWrap) {
    wrapWithSasl(response, call);
  }*/
  call.setResponse(ByteBuffer.wrap(response.toByteArray()));
}
 

import org.apache.hadoop.io.Writable; //導入方法依賴的package包/類
/**
 * @param w writable
 * @return The bytes of <code>w</code> gotten by running its
 * {@link Writable#write(java.io.DataOutput)} method.
 * @throws IOException e
 * @see #getWritable(byte[], Writable)
 */
public static byte [] getBytes(final Writable w) throws IOException {
  if (w == null) {
    throw new IllegalArgumentException("Writable cannot be null");
  }
  ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
  DataOutputStream out = new DataOutputStream(byteStream);
  try {
    w.write(out);
    out.close();
    out = null;
    return byteStream.toByteArray();
  } finally {
    if (out != null) {
      out.close();
    }
  }
}
 

import org.apache.hadoop.io.Writable; //導入方法依賴的package包/類
@Deprecated
public static void cloneWritableInto(Writable dst, 
                                     Writable src) throws IOException {
  CopyInCopyOutBuffer buffer = CLONE_BUFFERS.get();
  buffer.outBuffer.reset();
  src.write(buffer.outBuffer);
  buffer.moveData();
  dst.readFields(buffer.inBuffer);
}
 

import org.apache.hadoop.io.Writable; //導入方法依賴的package包/類
@Deprecated
public static void cloneWritableInto(Writable dst, 
                                     Writable src) throws IOException {
  CopyInCopyOutBuffer buffer = cloneBuffers.get();
  buffer.outBuffer.reset();
  src.write(buffer.outBuffer);
  buffer.moveData();
  dst.readFields(buffer.inBuffer);
}
 

import org.apache.hadoop.io.Writable; //導入方法依賴的package包/類
public void writeWritable(Writable w) throws IOException {
  ByteArrayOutputStream baos = new ByteArrayOutputStream();
  DataOutputStream dos = new DataOutputStream(baos);
  WritableUtils.writeString(dos, w.getClass().getName());
  w.write(dos);
  dos.close();
  out.writeBytes(baos.toByteArray(), Type.WRITABLE.code);
}
 

import org.apache.hadoop.io.Writable; //導入方法依賴的package包/類
@Override
public void serialize(Writable w) throws IOException {
  w.write(dataOut);
}
 

import org.apache.hadoop.io.Writable; //導入方法依賴的package包/類
public void serialize(Writable w) throws IOException {
  w.write(dataOut);
}