Android解析xml檔案獲取資料練習
阿新 • • 發佈：2019-01-29
前幾天單詞app中，已經可以顯示單詞了，對比有道詞典的單詞表，主要是有單詞備註的功能，可以進行聯想記憶，而且程式佔用空間小，沒有太多的通知資訊。
以前使用有道詞典的單詞儲存了一些單詞，有道里的單詞可以匯出到xml檔案中
格式如下
<wordbook><item> <word>unveil</word> <trans><![CDATA[vt. 使公諸於眾，揭開；揭幕 vi. 除去面紗；顯露 unveil: 揭露 | 使公諸於眾 | 揭開]]></trans> <phonetic><![CDATA[[ʌn'veɪl]]]></phonetic> <tags></tags> <progress>2</progress> </item><item> <word>prominence</word> <trans><![CDATA[n. 突出；顯著；突出物；卓越 Prominence: 日珥 | 突出 | 顯著]]></trans> <phonetic><![CDATA[['prɒmɪnəns]]]></phonetic> <tags></tags> <progress>1</progress> </item></wordbook>
考慮增加匯入功能，讀取單詞xml獲取資料儲存進去
在java上進行xml解析練習
import javax.xml.parsers.*; import org.w3c.dom.*; public class Test { public static void getDataFromXml(String fileName) { DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); try { DocumentBuilder db = dbf.newDocumentBuilder(); Document doc = db.parse(fileName); NodeList wordList = doc.getElementsByTagName("item"); System.out.println("共有" + wordList.getLength() + "個word節點"); for (int i = 0; i < wordList.getLength(); i++) { if (i == 3) { break; } Node aWord = wordList.item(i); Element elem = (Element) aWord; for (Node node = elem.getFirstChild(); node != null; node = node.getNextSibling()) { // System.out.println("node.getNodeType() = " + node.getNodeType()); if (node.getNodeType() == Node.ELEMENT_NODE) { String name = node.getNodeName(); if (name.equals("word") || name.equals("trans")) { String value = node.getFirstChild().getNodeValue(); System.out.print(name + ":" + value + "\t"); } } } System.out.println(); } } catch (Exception e) { e.printStackTrace(); System.out.println(e); } } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("----------"); getDataFromXml("D:\\2015\\06\\words.xml"); } }
把解析方法移植到單詞app中，出現錯誤，MalformedURLException: Protocol not found
解決方案，路徑修改為 file:///mnt/sdcard/words.xml
即增加file://
/mnt/sdcard/words.xml
為xml檔案儲存的地方，即手機上開啟 檔案管理 所在的路徑
呼叫// public void getDataFromXml(String fileName) { Log.d("test614", fileName); DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); try { DocumentBuilder db = dbf.newDocumentBuilder(); Document doc = db.parse(fileName); NodeList wordList = doc.getElementsByTagName("item"); System.out.println("共有" + wordList.getLength() + "個word節點"); Log.d("test614", "共有" + wordList.getLength() + "個word節點"); for (int i = 0; i < wordList.getLength(); i++) { Node aWord = wordList.item(i); Element elem = (Element) aWord; String wname = " "; String wtrans = " "; for (Node node = elem.getFirstChild(); node != null; node = node.getNextSibling()) { if (node.getNodeType() == Node.ELEMENT_NODE) { String name = node.getNodeName(); if (name.equals("word")) { wname = node.getFirstChild().getNodeValue(); } if (name.equals("trans")) { wtrans = node.getFirstChild().getNodeValue(); } } } if (!wname.equals(" ")) { this.insertStuInfo(wname, wtrans, " "); } } } catch (Exception e) { e.printStackTrace(); System.out.println(e); Log.d("test614", e.toString()); } }
getDataFromXml("file:///mnt/sdcard/words.xml");//insert
a record
//6-21
private void insertStuInfo(String word, String trans, String notes)
{
ContentValues values = new ContentValues();
values.put(StuInfoColumns.WORD_NAME, word);
values.put(StuInfoColumns.WORD_MEANING, trans);
values.put(StuInfoColumns.WORD_NOTES, notes);
getContentResolver().insert(StuInfoColumns.CONTENT_URI, values);
}
根據字母表排序的單詞對出現大寫字母優先於小寫字母的現象，可以使用upper對排序條件進行修飾
增加解析tags內容後，發現如果內容為空，會出錯
node.getFirstChild().getNodeValue()
//will lead a nullPointer exception解析方法的優化：
//
public void getDataFromXml(String fileName)
{
Log.d("test614", fileName);
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try
{
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(fileName);
NodeList wordList = doc.getElementsByTagName("item");
System.out.println("共有" + wordList.getLength() + "個word節點");
Log.d("test614", "共有" + wordList.getLength() + "個word節點");
for (int i = 0; i < wordList.getLength(); i++)
{
Node aWord = wordList.item(i);
Element elem = (Element) aWord;
String wname = " ";
String wtrans = " ";
String wnotes = " ";
for (Node node = elem.getFirstChild(); node != null; node = node.getNextSibling())
{
if (node.getNodeType() == Node.ELEMENT_NODE)
{
//if there is no value, continue
//otherwise node.getFirstChild().getNodeValue()
//will lead a nullPointer exception
if (node.getFirstChild() == null)
{
continue;
}
String name = node.getNodeName();
if (name.equals("word") )
{
wname = node.getFirstChild().getNodeValue();
Log.d("test614", "word=" + wname);
}
else if (name.equals("trans"))
{
//node.getNodeValue()
wtrans = node.getFirstChild().getNodeValue();
Log.d("test614", "trans=" + wtrans);
}
else if (name.equals("tags"))
{
wnotes = node.getFirstChild().getNodeValue();
if (wnotes == null)
{
Log.d("test614", "tags=null");
}
else
{
Log.d("test614", "tags=" + wnotes);
}
}
}
}
if (wname!= null && !wname.equals(" "))
{
Log.d("test614", "if (!wname.equals() " + wname);
this.insertStuInfo(wname, wtrans, wnotes);
}
}
}
catch (Exception e)
{
e.printStackTrace();
System.out.println(e);
Log.d("test614", e.toString());
}
}