| /** |
| * 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.hadoop.hdfs.tools.offlineImageViewer; |
| |
| import java.io.IOException; |
| import java.util.LinkedList; |
| |
| /** |
| * An XmlImageVisitor walks over an fsimage structure and writes out |
| * an equivalent XML document that contains the fsimage's components. |
| */ |
| class XmlImageVisitor extends TextWriterImageVisitor { |
| final private LinkedList<ImageElement> tagQ = |
| new LinkedList<ImageElement>(); |
| |
| public XmlImageVisitor(String filename) throws IOException { |
| super(filename, false); |
| } |
| |
| public XmlImageVisitor(String filename, boolean printToScreen) |
| throws IOException { |
| super(filename, printToScreen); |
| } |
| |
| @Override |
| void finish() throws IOException { |
| super.finish(); |
| } |
| |
| @Override |
| void finishAbnormally() throws IOException { |
| write("\n<!-- Error processing image file. Exiting -->\n"); |
| super.finishAbnormally(); |
| } |
| |
| @Override |
| void leaveEnclosingElement() throws IOException { |
| if(tagQ.size() == 0) |
| throw new IOException("Tried to exit non-existent enclosing element " + |
| "in FSImage file"); |
| |
| ImageElement element = tagQ.pop(); |
| write("</" + element.toString() + ">\n"); |
| } |
| |
| @Override |
| void start() throws IOException { |
| write("<?xml version=\"1.0\" ?>\n"); |
| } |
| |
| @Override |
| void visit(ImageElement element, String value) throws IOException { |
| writeTag(element.toString(), value); |
| } |
| |
| @Override |
| void visitEnclosingElement(ImageElement element) throws IOException { |
| write("<" + element.toString() + ">\n"); |
| tagQ.push(element); |
| } |
| |
| @Override |
| void visitEnclosingElement(ImageElement element, |
| ImageElement key, String value) |
| throws IOException { |
| write("<" + element.toString() + " " + key + "=\"" + value +"\">\n"); |
| tagQ.push(element); |
| } |
| |
| private void writeTag(String tag, String value) throws IOException { |
| write("<" + tag + ">" + value + "</" + tag + ">\n"); |
| } |
| } |