| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 |
| * |
| * http://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.apache.wayang.api.python.executor; |
| |
| import java.io.DataInputStream; |
| import java.io.IOException; |
| import java.nio.charset.StandardCharsets; |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| |
| public class ReaderIterator <Output> implements Iterator<Output> { |
| |
| private Output nextObj = null; |
| private boolean eos = false; |
| private boolean fst = false; |
| private DataInputStream stream = null; |
| |
| public ReaderIterator(DataInputStream stream) { |
| |
| this.stream = stream; |
| this.eos = false; |
| this.nextObj = null; |
| } |
| |
| private Output read() { |
| |
| int END_OF_DATA_SECTION = -1; |
| |
| try { |
| int length = this.stream.readInt(); |
| |
| if (length > 0) { |
| byte[] obj = new byte[length]; |
| stream.readFully(obj); |
| String s = new String(obj, StandardCharsets.UTF_8); |
| Output it = (Output) s; |
| return it; |
| } else if (length == END_OF_DATA_SECTION) { |
| this.eos = true; |
| return null; |
| } |
| } catch (IOException e) { |
| //e.printStackTrace(); |
| throw new RuntimeException(e); |
| } |
| return null; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| |
| if(!this.eos){ |
| nextObj = read(); |
| System.out.println(nextObj + " " + !this.eos); |
| |
| /*To work with null values it is suppose to use -5 |
| if(this.nextObj == null){ |
| return false; |
| }*/ |
| |
| return !this.eos; |
| } |
| |
| return false; |
| } |
| |
| @Override |
| public Output next() { |
| |
| if(!this.eos){ |
| Output obj = nextObj; |
| nextObj = null; |
| return obj; |
| } |
| |
| throw new NoSuchElementException(); |
| } |
| |
| } |