标签:style blog color java os io 文件 for
从xml文件中得到某个节点中value的值,条件是已知道某一个子节点的参数,如下一片段,
已知 <name> 为 “Motor hand”的值,想从整个xml文件中得到此子节点的<value>所对应的值。
“<field>
<name>Motor hand</name>
<value>Right</value>
<type>Dotted</type>
</field>”
此方法是dom 遍历,获取大的节点并解析出子节点并属性和值一起存入到map中,将所有大节点再加入到链表中以备之后的其他程序调用(另附,从文件读取xml文件的方法):
1 public static void main(String[] args) 2 {
//"strxml"是 xml 转的string, 是个完整的xml对应的字符串,
3 String result=findbynode(strxml,"field","name","Motor hand","value");
4 System.out.print(result);
5 //得到的结果是“Right”
6
7 8 } 9 10 /** 11 * common method "findbynode" get target from Xml 2 12 * 13 * @param args example: 14 * 15 * { 16 * <field> //field-->bignode 17 * <name>Motor hand</name> //name-->clum1 , "Motor hand"-->itemvalue 18 * <value>Right</value> //value-->clum2 19 * <type>Dotted</type> 20 * </field> 21 * } 22 * 23 */ 24 public static String findbynode(String passxmlstr,String bignode,String clum1,String itemvalue,String clum2) 25 { 26 String result=""; 27 28 /* 29 bignode="field"; 30 clum1="name"; 31 clum2="value"; 32 */ 33 34 ArrayList<Map> al=paserxmlbynode(passxmlstr,bignode); 35 for(Map m : al) 36 { 37 if(m.get(clum1).toString().equals(itemvalue)) 38 { 39 result=m.get(clum2).toString(); 40 break; 41 } 42 } 43 //System.out.println(result); 44 return result; 45 } 46 47 public static ArrayList paserxmlbynode(String passxmlstr,String bignode) 48 { 49 Document xmlDoc=null; 50 51 try { 52 ByteArrayInputStream bis = new ByteArrayInputStream(passxmlstr.getBytes("UTF-8")); 53 xmlDoc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(bis); 54 } catch (Throwable e) { 55 try { 56 throw new Exception("MSG_COULDN‘T_PARSE_XML", e); 57 } catch (Exception e1) { 58 // TODO Auto-generated catch block 59 e1.printStackTrace(); 60 } 61 } 62 63 // System.out.print(passxmlstr); 64 ArrayList<Map> listitem=new ArrayList<Map>(); 65 66 // find bignode 67 NodeList nlds=xmlDoc.getElementsByTagName(bignode); 68 int size =nlds.getLength(); 69 for(int j=0;j<size;j++) 70 { 71 Node nd=nlds.item(j).getFirstChild().getNextSibling(); 72 Map<String,String> map=new HashMap<String,String>(); 73 while(nd!=null) 74 { 75 map.put(nd.getNodeName(), nd.getFirstChild().getNodeValue()); 76 nd= nd.getNextSibling().getNextSibling(); 77 } 78 listitem.add(map); 79 } 80 81 // System.out.print(listitem.size()); 82 return listitem; 83 } 84
附:从文件读取xml文件
1 public String getStringofxmlfromdisk() 2 { 3 String passxmlstr = ""; 4 String filepath="D:\\test\\rxml.xml"; 5 6 BufferedReader reader = null; 7 try { 8 reader = new BufferedReader(new FileReader(new File(filepath))); 9 String tempString = null; 10 int line = 1; 11 while ((tempString = reader.readLine()) != null) { 12 passxmlstr += tempString; 13 line++; 14 } 15 // System.out.println(" " + passxmlstr); 16 reader.close(); 17 } catch (IOException e) { 18 e.printStackTrace(); 19 } finally { 20 if (reader != null) { 21 try { 22 reader.close(); 23 } catch (IOException e1) { 24 } 25 } 26 } 27 return passxmlstr; 28 }
标签:style blog color java os io 文件 for
原文地址:http://www.cnblogs.com/rojas/p/3919465.html