java 对xml文件进行 增删改查

<?xml version="1.0" encoding="UTF-8"?>
<CDRS>
<cdr name="1">
<username>ss</username>
<password>dd</password>
</cdr>
<cdr name="2">
<username>ss</username>
<password>dd</password>
</cdr>
<cdr name="3">
<username>ss</username>
<password>dd</password>
</cdr>
<cdr name="4">
<username>ss</username>
<password>dd</password>
</cdr>
<cdr name="5">
<username>ss</username>
<password>dd</password>
</cdr>
<cdr name="6">
<username>jiang</username>
<username>12345s</username>
</cdr>
<cdr name="7">
<username>iiiii</username>
<username>12345s</username>
</cdr>
</CDRS>

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;
import org.jdom.output.XMLOutputter;

public class TestXml {
/**
* 新建一个最新的xml 并保存到项目根目录
*/
public static void printXml() {
// 定义一个root作为xml文档的根元素
Element root = new Element("CDRS");
// 生成一个文档
Document Doc = new Document(root);
for (int j = 1; j <= 5; j++) {
// 在生成的名称为CDRS的跟元素下生成下一级元素标签名称为cdr
Element elements = new Element("cdr");
// 为cdr设置属性名和属性值
elements.setAttribute("name", "" + j);
// 在cdr标签内部添加新的元素，即cdr的下一级标签，标签属性名为username,值为ss
elements.addContent(new Element("username").setText("ss"));
elements.addContent(new Element("password").setText("dd"));
// 将已经设置好值的elements赋给root
root.addContent(elements);
}
// 定义一个用于输出xml文档的类
XMLOutputter XMLOut = new XMLOutputter();
try {
// 将生成的xml文档Doc输出到c盘的test.xml文档中
XMLOut.output(Doc, new FileOutputStream("./test.xml"));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

/**
* 获取xml 文件  根据 name 值 修改修改
* @throws Exception
*/
public static void editItem() throws Exception{
SAXBuilder sb = new SAXBuilder();
Document doc = sb.build("./test.xml");
Element root = doc.getRootElement();
List<Element> list = root.getChildren("cdr");
for(Element ele : list){
//判断 name  是否为7  为7 就修改 username值
if(ele.getAttributeValue("name").equals("7")){
Element un = ele.getChild("username");
un.setText("iiiii");
}
}
XMLOutputter XMLOut = new XMLOutputter();
XMLOut.output(doc, new FileOutputStream("./test.xml"));
}

/**
* 获取xml 文件 添加 一个数据项
* @throws Exception
*/
public static void addItem() throws Exception{
SAXBuilder sb = new SAXBuilder();
Document doc = sb.build("./test.xml");
Element root = doc.getRootElement();
Element elements = new Element("cdr");
elements.setAttribute("name", "7");
elements.addContent(new Element("username").setText("jiang"));
elements.addContent(new Element("username").setText("12345s"));
root.addContent(elements);
XMLOutputter XMLOut = new XMLOutputter();
XMLOut.output(doc, new FileOutputStream("./test.xml"));
}

}