/**
?????*?DOM4J讀寫XML示例
?????*?
?????*? @param ?args
?????*? @throws ?Exception
????? */
???? public ? static ? void ?main(String[]?args)? {
???????? try ? {
????????????XMLWriter?writer? = ? null ; // ?聲明寫XML的對象
????????????SAXReader?reader? = ? new ?SAXReader();

????????????OutputFormat?format? = ?OutputFormat.createPrettyPrint();
????????????format.setEncoding( " GBK " ); // ?設置XML文件的編碼格式

????????????String?filePath? = ? " d:\\student.xml " ;
????????????File?file? = ? new ?File(filePath);
???????????? if ?(file.exists())? {
????????????????Document?document? = ?reader.read(file); // ?讀取XML文件
????????????????Element?root? = ?document.getRootElement(); // ?得到根節點
???????????????? boolean ?bl? = ? false ;
???????????????? for ?(Iterator?i? = ?root.elementIterator( " 學生 " );?i.hasNext();)? {
????????????????????Element?student? = ?(Element)?i.next();
???????????????????? if ?(student.attributeValue( " sid " ).equals( " 001 " ))? {
???????????????????????? // ?修改學生sid=001的學生信息
????????????????????????student.selectSingleNode( " 姓名 " ).setText( " 王五 " );
????????????????????????student.selectSingleNode( " 年齡 " ).setText( " 25 " );

????????????????????????writer? = ? new ?XMLWriter( new ?FileWriter(filePath),?format);
????????????????????????writer.write(document);
????????????????????????writer.close();
????????????????????????bl? = ? true ;
???????????????????????? break ;
????????????????????}
????????????????}
???????????????? if ?(bl)? {
???????????????????? // ?添加一個學生信息
????????????????????Element?student? = ?root.addElement( " 學生 " );
????????????????????student.addAttribute( " sid " ,? " 100 " );
????????????????????Element?sid? = ?student.addElement( " 編號 " );
????????????????????sid.setText( " 100 " );
????????????????????Element?name? = ?student.addElement( " 姓名 " );
????????????????????name.setText( " 嘎嘎 " );
????????????????????Element?sex? = ?student.addElement( " 性別 " );
????????????????????sex.setText( " 男 " );
????????????????????Element?age? = ?student.addElement( " 年齡 " );
????????????????????age.setText( " 21 " );

????????????????????writer? = ? new ?XMLWriter( new ?FileWriter(filePath),?format);
????????????????????writer.write(document);
????????????????????writer.close();
????????????????}
????????????} ? else ? {
???????????????? // ?新建student.xml文件并新增內容
????????????????Document?_document? = ?DocumentHelper.createDocument();
????????????????Element?_root? = ?_document.addElement( " 學生信息 " );
????????????????Element?_student? = ?_root.addElement( " 學生 " );
????????????????_student.addAttribute( " sid " ,? " 001 " );
????????????????Element?_id? = ?_student.addElement( " 編號 " );
????????????????_id.setText( " 001 " );
????????????????Element?_name? = ?_student.addElement( " 姓名 " );
????????????????_name.setText( " 灰機 " );
????????????????Element?_age? = ?_student.addElement( " 年齡 " );
????????????????_age.setText( " 18 " );

????????????????writer? = ? new ?XMLWriter( new ?FileWriter(file),?format);
????????????????writer.write(_document);
????????????????writer.close();
????????????}
????????????System.out.println( " 操作結束!? " );
????????} ? catch ?(Exception?e)? {
????????????e.printStackTrace();
????????}

????}
}

執行結果應該是這樣：



循環解析節點：

其次DOM4J的解釋

一.Document對象相關

1.讀取XML文件,獲得document對象.

2.解析XML形式的文本,得到document對象.

?????? String?text? = ? " <members></members> ";
??????Document?document? = ?DocumentHelper.parseText(text);

3.主動創建document對象.

??????Document?document? =?DocumentHelper.createDocument();
??????Element?root? = ?document.addElement( " members " ); // ?創建根節點

二.節點相關

1.獲取文檔的根節點.

????? Element?rootElm? = ?document.getRootElement();

2.取得某節點的單個子節點.

????? Element?memberElm = root.element( " member " ); // ?"member"是節點名

3.取得節點的文字

????? String text = memberElm.getText();

也可以用:

????? String text = root.elementText( " name " );

這個是取得根節點下的name字節點的文字.

4.取得某節點下名為"member"的所有字節點并進行遍歷.

List?nodes? = ?rootElm.elements( " member ");

for ?(Iterator?it? = ?nodes.iterator();?it.hasNext();)? {
????Element?elm? =?(Element)?it.next();
??? // ?do?something
}

5.對某節點下的所有子節點進行遍歷.

? for (Iterator?it = root.elementIterator();it.hasNext();) {
?????????????????Element?element? = ?(Element)?it.next();
???????????????? // ?do?something
?????????????}

6.在某節點下添加子節點.

Element ageElm = newMemberElm.addElement( " age " );

7.設置節點文字.

ageElm.setText( " 29 " );

8.刪除某節點.

parentElm.remove(childElm); // childElm是待刪除的節點,parentElm是其父節點

9.添加一個CDATA節點.

???????? Element contentElm = infoElm.addElement( " content " );
???????? contentElm.addCDATA(diary.getContent());

????????????contentElm.getText(); // 特別說明：獲取節點的CDATA值與獲取節點的值是一個方法
????????????contentElm.clearContent(); //清除節點中的內容，CDATA亦可

三.屬性相關.
1.取得某節點下的某屬性

???????????? Element root = document.getRootElement();????
???????????? Attribute attribute = root.attribute( " size " ); // 屬性名name

2.取得屬性的文字

???????????? String text = attribute.getText();

也可以用:

String text2 = root.element( " name " ).attributeValue( " firstname " );

這個是取得根節點下name字節點的屬性firstname的值.

3.遍歷某節點的所有屬性

??Element?root = document.getRootElement();????
???????????? for (Iterator?it = root.attributeIterator();it.hasNext();) {
?????????????????Attribute?attribute? = ?(Attribute)?it.next();
?????????????????String?text = attribute.getText();
?????????????????System.out.println(text);
?????????????}

4.設置某節點的屬性和文字.

newMemberElm.addAttribute( " name " , " sitinspring " );

5.設置屬性的文字

???????????? Attribute attribute = root.attribute( " name " );
???????????? attribute.setText( " sitinspring " );

6.刪除某屬性

???????????? Attribute attribute = root.attribute( " size " ); // 屬性名name
???????????? root.remove(attribute);

四.將文檔寫入XML文件.
1.文檔中全為英文,不設置編碼,直接寫入的形式.

XMLWriter writer = new XMLWriter( new FileWriter( " output.xml " ));
writer.write(document);
writer.close();

2.文檔中含有中文,設置編碼格式寫入的形式.

???????????? OutputFormat format = OutputFormat.createPrettyPrint();
???????????? format.setEncoding( " GBK " );???? // 指定XML編碼????????
???????????? XMLWriter writer = new XMLWriter( new FileWriter( " output.xml " ),format);
????????????
???????????? writer.write(document);
???????????? writer.close();

五.字符串與XML的轉換
1.將字符串轉化為XML

String text = " <members> <member>sitinspring</member> </members> " ;
Document document = DocumentHelper.parseText(text);

2.將文檔或節點的XML轉化為字符串.

???????????? SAXReader reader = new SAXReader();
???????????? Document?? document = reader.read( new File( " input.xml " ));????????????
???????????? Element root = document.getRootElement();????????????????
???????????? String docXmlText = document.asXML();
???????????? String rootXmlText = root.asXML();
???????????? Element memberElm = root.element( " member " );
???????????? String memberXmlText = memberElm.asXML();

dom4j讀寫xml文件