XML-可扩展标记语言 ，用于标记电子文件使其具有结构性的标记语言，可以用来标记数据、定义数据类型，是一种允许用户对自己的标记语言进行定义的源语言，被广泛的运用于数据传输和存储。请编写一段程序，不使用语言之外的开源库，解析对应的XML文件，并格式化后在屏幕上打印出来。
举个例子如下，当给定下述XML文件时：
<?xml version="1.0" ?>
<Books>
<Book>
<Name = “The C++ Programming Language” Author=”Bjarne Stroustrup” />
</Book>
<Book>
<Name = “Effective C++” Author = “Scott Meyers” />
</Book>
</Books>
它对应的输出应该是：
Books
Book 1
Name:The C++ Programming Language
Author:Bjarne Stroustrup
Book 2
Name:Effective C++
Author:Scott Meyers
输入：简化的一段xml文件，用字符串表示，如下（属性名字不包含引号和等号，也不包含大于小于等特殊字符，详细规则见下面的答题说明）
string in = "<?xml version=\"1.0\" ?><Books><Book><Name = \"The C++ Programming Language\" Author=\"Bjarne Stroustrup\" /></Book><Book><Name = \"Effective C++\" Author = \"Scott Meyers\" /></Book></Books>";
string out = "Books\r\n\tBook 1\r\n\t\tName:The C++ Programming Language\r\n\t\tAuthor:Bjarne Stroustrup\r\n\tBook 2\r\n\t\tName:Effective C++\r\n\t\tAuthor:Scott Meyers";
我的结果：
import java.util.ArrayList; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; public class XMLparse { public static String ParsingXML(String in) { in = removeHeader(in); StringBuilder sb = new StringBuilder(); String level_1 = getLevelTag(in); sb.append(level_1+"\r\n"); String level_1_Str = getXmlValue(in,level_1); String level_2 = getLevelTag(level_1_Str); List<String> level_2_list = getXmlList(in,level_2); for(String level_2_Str : level_2_list){ sb.append("\t"+level_2+"\r\n"); sb.append(getAttrVal(level_2_Str)); } return sb.toString(); } private static String getLevelTag(String xml){ Pattern p = Pattern.compile("<.*?>",Pattern.DOTALL); Matcher m = p.matcher(xml); String retStr = null; if(m.find()){ retStr = m.group(); } return null != retStr ? retStr.replace("<","").replace(">",""):""; } private static StringBuilder getAttrVal(String xml){ StringBuilder sb = new StringBuilder(); Pattern p = Pattern.compile("(\\w+)\\s*=\\s*\"([^\"]+)\"",Pattern.DOTALL); Matcher m = p.matcher(xml); String retStr = null; while(m.find()){ retStr = m.group(); if(retStr.indexOf("=")>0){ sb.append("\t\t"+retStr.split("=")[0]+":"+retStr.split("=")[1]+"\r\n"); } } return sb; } private static String removeHeader(String in){ Pattern p = Pattern.compile("<\\?.*?xml.*? \\?>",Pattern.DOTALL); Matcher m = p.matcher(in); String retStr = null; if(m.find()){ retStr = in.replace(m.group(),""); } return retStr; } private static String getXmlValue(String xml,String filePath) { String rtnMsg = ""; if (null == xml || null == filePath || "".equals(xml) || "".equals(filePath)) { return rtnMsg; } filePath = filePath.replace("\r\n",""); filePath = filePath.replace("\t",""); String[] paths = filePath.split("/"); String xmlRes = "(.*?)"; String path; for (int i = paths.length - 1; i >= 0; i--) { path = paths[i]; if (i == paths.length - 1) { xmlRes = "<" + path.trim() + ">" + xmlRes + "</" + path.trim() + ">"; } else { xmlRes = "<" + path.trim() + ">.*?" + xmlRes + ".*?</" + path.trim() + ">"; } } Pattern pattern = Pattern.compile(xmlRes,Pattern.DOTALL); Matcher matcher = pattern.matcher(xml); while (matcher.find()) { rtnMsg = matcher.group(1); return rtnMsg; } return rtnMsg; } private static List<String> getXmlList(String xml,String filePath) { List<String> list = new ArrayList<String>(); if (null == xml || null == filePath || "".equals(xml) || "".equals(filePath)) { return list; } filePath = filePath.replace("\r\n",Pattern.DOTALL); Matcher matcher = pattern.matcher(xml); while (matcher.find()) { list.add(matcher.group(1)); } return list; } //start 提示：自动阅卷起始唯一标识，请勿删除或增加。 public static void main(String args[]) { String in = "<?xml version=\"1.0\" ?><Books><Book><Name = \"The C++ Programming Language\" Author=\"Bjarne Stroustrup\" /></Book><Book><Name = \"Effective C++\" Author = \"Scott Meyers\" /></Book></Books>"; System.out.println(ParsingXML(in)); } //end //提示：自动阅卷结束唯一标识，请勿删除或增加。 }
