1 /* 2 * Copyright (C) 2009 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.sdklib.internal.repository; 18 19 import org.w3c.dom.Node; 20 21 /** 22 * Misc utilities to help extracting elements and attributes out of an XML document. 23 */ 24 class XmlParserUtils { 25 26 /** 27 * Returns the first child element with the given XML local name. 28 * If xmlLocalName is null, returns the very first child element. 29 */ getFirstChild(Node node, String xmlLocalName)30 public static Node getFirstChild(Node node, String xmlLocalName) { 31 32 String nsUri = node.getNamespaceURI(); 33 for(Node child = node.getFirstChild(); child != null; child = child.getNextSibling()) { 34 if (child.getNodeType() == Node.ELEMENT_NODE && 35 nsUri.equals(child.getNamespaceURI())) { 36 if (xmlLocalName == null || xmlLocalName.equals(child.getLocalName())) { 37 return child; 38 } 39 } 40 } 41 42 return null; 43 } 44 45 /** 46 * Retrieves the value of that XML element as a string. 47 * Returns an empty string whether the element is missing or empty, 48 * so you can't tell the difference. 49 * <p/> 50 * Note: use {@link #getOptionalXmlString(Node, String)} if you need to know when the 51 * element is missing versus empty. 52 * 53 * @param node The XML <em>parent</em> node to parse. 54 * @param xmlLocalName The XML local name to find in the parent node. 55 * @return The text content of the element. Returns an empty string whether the element 56 * is missing or empty, so you can't tell the difference. 57 */ getXmlString(Node node, String xmlLocalName)58 public static String getXmlString(Node node, String xmlLocalName) { 59 Node child = getFirstChild(node, xmlLocalName); 60 61 return child == null ? "" : child.getTextContent(); //$NON-NLS-1$ 62 } 63 64 /** 65 * Retrieves the value of that XML element as a string. 66 * Returns null when the element is missing, so you can tell between a missing element 67 * and an empty one. 68 * <p/> 69 * Note: use {@link #getXmlString(Node, String)} if you don't need to know when the 70 * element is missing versus empty. 71 * 72 * @param node The XML <em>parent</em> node to parse. 73 * @param xmlLocalName The XML local name to find in the parent node. 74 * @return The text content of the element. Returns null when the element is missing. 75 * Returns an empty string whether the element is present but empty. 76 */ getOptionalXmlString(Node node, String xmlLocalName)77 public static String getOptionalXmlString(Node node, String xmlLocalName) { 78 Node child = getFirstChild(node, xmlLocalName); 79 80 return child == null ? null : child.getTextContent(); //$NON-NLS-1$ 81 } 82 83 /** 84 * Retrieves the value of that XML element as an integer. 85 * Returns the default value when the element is missing or is not an integer. 86 */ getXmlInt(Node node, String xmlLocalName, int defaultValue)87 public static int getXmlInt(Node node, String xmlLocalName, int defaultValue) { 88 String s = getXmlString(node, xmlLocalName); 89 try { 90 return Integer.parseInt(s); 91 } catch (NumberFormatException e) { 92 return defaultValue; 93 } 94 } 95 96 /** 97 * Retrieves the value of that XML element as a long. 98 * Returns the default value when the element is missing or is not an integer. 99 */ getXmlLong(Node node, String xmlLocalName, long defaultValue)100 public static long getXmlLong(Node node, String xmlLocalName, long defaultValue) { 101 String s = getXmlString(node, xmlLocalName); 102 try { 103 return Long.parseLong(s); 104 } catch (NumberFormatException e) { 105 return defaultValue; 106 } 107 } 108 109 /** 110 * Retrieve an attribute which value must match one of the given enums using a 111 * case-insensitive name match. 112 * 113 * Returns defaultValue if the attribute does not exist or its value does not match 114 * the given enum values. 115 */ getEnumAttribute( Node archiveNode, String attrName, Object[] values, Object defaultValue)116 public static Object getEnumAttribute( 117 Node archiveNode, 118 String attrName, 119 Object[] values, 120 Object defaultValue) { 121 122 Node attr = archiveNode.getAttributes().getNamedItem(attrName); 123 if (attr != null) { 124 String found = attr.getNodeValue(); 125 for (Object value : values) { 126 if (value.toString().equalsIgnoreCase(found)) { 127 return value; 128 } 129 } 130 } 131 132 return defaultValue; 133 } 134 135 } 136