Dom4j使用示例
Dom4j 是一个易用的、开源的库，用于 XML ， XPath 和 XSLT 。它应用于 Java 平台，采用了 Java 集合框架并完全支持 DOM ， SAX 和 JAXP 。
要使用dom4j读写XML文档,需要先下载dom4j包
下载dom4j-1.6.1.zip
解开后有两个包,仅操作XML文档的话把dom4j-1.6.1.jar加入工程就可以了,如果需要使用XPath的话还需要加入包jaxen-1.1-beta-7.jar
先上xml文件
<?xml version="1.0" encoding="UTF-8"?>
<mxGraphModel>
<root>
<mxCell id="0" />
<mxCell id="1" parent="0" />
<mxCell id="2" parent="1" vertex="1">
<Activity4Graph as="value" isLeaf="Y" name="活动1"
state="C" />
<mxGeometry as="geometry" height="70.0" width="100.0" x="290.0"
y="90.0" />
</mxCell>
<mxCell id="3" parent="1" vertex="1">
<Activity4Graph AId="7efcc9a6-9d7e-11df-9842-1d6abb6dee61"
as="value" isLeaf="N" name="活动2" state="C" />
<mxGeometry as="geometry" height="70.0" width="100.0" x="40.0"
y="190.0" />
</mxCell>
<mxCell edge="1" id="4" parent="1" source="2" style="" target="3">
<ActivityRelation4Graph as="value" name="连线3" />
<mxGeometry as="geometry" relative="1">
<mxPoint as="sourcePoint" x="360.0" y="145.0" />
<mxPoint as="targetPoint" x="140.0" y="260.0" />
</mxGeometry>
</mxCell>
<mxCell id="5" parent="1" vertex="1">
<Activity4Graph AId="936d24de-9dd9-11df-9842-1d6abb6dee61"
as="value" isLeaf="N" name="活动4" state="C" />
<mxGeometry as="geometry" height="70.0" width="100.0" x="270.0"
y="340.0" />
</mxCell>
<mxCell edge="1" id="6" parent="1" source="3" style="" target="5">
<ActivityRelation4Graph as="value" name="连线5" />
<mxGeometry as="geometry" relative="1">
<mxPoint as="sourcePoint" x="130.0" y="255.0" />
<mxPoint as="targetPoint" x="360.0" y="380.0" />
</mxGeometry>
</mxCell>
<mxCell id="7" parent="1" vertex="1">
<Activity4Graph as="value" isLeaf="Y" name="活动6"
state="C" />
<mxGeometry as="geometry" height="70.0" width="100.0" x="510.0"
y="260.0" />
</mxCell>
<mxCell edge="1" id="8" parent="1" source="5" style="" target="7">
<ActivityRelation4Graph as="value" name="连线7" />
<mxGeometry as="geometry" relative="1">
<mxPoint as="sourcePoint" x="350.0" y="385.0" />
<mxPoint as="targetPoint" x="580.0" y="330.0" />
</mxGeometry>
</mxCell>
<mxCell id="9" parent="1" vertex="1">
<Activity4Graph as="value" isLeaf="Y" name="活动8"
state="C" />
<mxGeometry as="geometry" height="70.0" width="100.0" x="490.0"
y="60.0" />
</mxCell>
<mxCell edge="1" id="10" parent="1" source="2" style="" target="9">
<ActivityRelation4Graph as="value" name="连线9" />
<mxGeometry as="geometry" relative="1">
<mxPoint as="sourcePoint" x="360.0" y="145.0" />
<mxPoint as="targetPoint" x="540.0" y="90.0" />
</mxGeometry>
</mxCell>
<mxCell id="A:3:R.12" parent="1" style="fillColor=#FFFFCC"
vertex="1">
<AARole4Graph aarID="9b8831d2-9d7e-11df-9842-1d6abb6dee61"
as="value" name="521_wa_5:wr1" />
<mxGeometry as="geometry" height="30.0" width="100.0" x="40.0"
y="260.0" />
</mxCell>
<mxCell id="A:3:I.13" parent="1" style="fillColor=#00FFCC"
vertex="1">
<Indicator4Graph as="value" graphID="A:3:I.13"
indicatorID="a1eb3199-9d7e-11df-9842-1d6abb6dee61" name="业务指标11" />
<mxGeometry as="geometry" height="10.0" width="10.0" x="40.0"
y="180.0">
<mxPoint as="offset" x="50.0" />
</mxGeometry>
</mxCell>
<mxCell id="11" parent="1" vertex="1">
<Activity4Graph as="value" isLeaf="Y" name="活动1"
state="C" />
<mxGeometry as="geometry" height="70.0" width="100.0" />
</mxCell>
</root>
</mxGraphModel>
解析代码
public class ReadXML {
public static Map<String, Location> maps;
static {
maps = new HashMap<String, Location>();
}
public static void main(String[] args) {
readXML("xml/demo.xml");
}
public static Map<String, Location> readXML(String path) {
Map<String, Location> mms= new HashMap<String, Location>();
SAXReader reader = new SAXReader();
try {
Document doc = reader.read(loadResource(path));
List<Element> eleList = doc
.selectNodes("/mxGraphModel/root/mxCell");
for (Element ele : eleList) {
// String id = ele.valueOf("@id");
Location loc = new Location();
List<Element> Activity4Graphs = ele.elements("Activity4Graph");// 获取某节点下指定节点
int size = DataOptUtil.getSize(Activity4Graphs);
if (size > 0) {
for (Element element : Activity4Graphs) {
String name = element.valueOf("@name");
if (DataOptUtil.isNotNull(name)) {
loc.setNodeName(name);
}
}
}
List<Element> Indicator4Graphs = ele
.elements("Indicator4Graph");// 获取某节点下指定节点
int size1 = DataOptUtil.getSize(Indicator4Graphs);
if (size1 > 0) {
for (Element element : Indicator4Graphs) {
String name = element.valueOf("@name");
if (DataOptUtil.isNotNull(name)) {
loc.setNodeName(name);
}
}
}
List<Element> AARole4Graphs = ele.elements("AARole4Graph");// 获取某节点下指定节点
int size2 = DataOptUtil.getSize(AARole4Graphs);
if (size2 > 0) {
for (Element element : AARole4Graphs) {
String name = element.valueOf("@name");
if (DataOptUtil.isNotNull(name)) {
loc.setNodeName(name);
}
}
}
List<Element> ActivityRelation4Graphs = ele
.elements("ActivityRelation4Graph");// 获取某节点下指定节点
int size3 = DataOptUtil.getSize(ActivityRelation4Graphs);
if (size3 > 0) {
for (Element element : ActivityRelation4Graphs) {
String name = element.valueOf("@name");
if (DataOptUtil.isNotNull(name)) {
loc.setNodeName(name);
}
}
}
List<Element> mxGeometryS = ele.elements("mxGeometry");
for (Element element : mxGeometryS) {
if (DataOptUtil.isNotNull(element.valueOf("@width"))) {
double width = Double
.valueOf(element.valueOf("@width"));
loc.setWidth(width);
}
if (DataOptUtil.isNotNull(element.valueOf("@height"))) {
double height = Double.valueOf(element
.valueOf("@height"));
loc.setHeight(height);
}
if (DataOptUtil.isNotNull(element.valueOf("@x"))) {
double x = Double.valueOf(element.valueOf("@x"));
loc.setValueX(x);
}
if (DataOptUtil.isNotNull(element.valueOf("@y"))) {
double y = Double.valueOf(element.valueOf("@y"));
loc.setValueY(y);
}
List<Element> mxPoints = element.elements("mxPoint");// 获取某节点下指定节点
int size4 = DataOptUtil.getSize(mxPoints);
if (size4 > 0) {
for (Element e : mxPoints) {
if (DataOptUtil.isNotNull(e.valueOf("@x"))) {
double x = Double.valueOf(e.valueOf("@x"));
loc.setValueX(x);
}
if (DataOptUtil.isNotNull(e.valueOf("@y"))) {
double y = Double.valueOf(e.valueOf("@y"));
loc.setValueY(y);
}
}
}
}
if (loc.getNodeName()!=null) {
//System.out.println(loc);
mms.put(loc.getNodeName(), loc);
}
}
for (Entry<String, Location> entry : maps.entrySet()) {
System.out.println(entry.getKey() + "===" + entry.getValue());
}
} catch (DocumentException e) {
e.printStackTrace();
}
return mms;
}
public static InputStream loadResource(String path) {
return Thread.currentThread().getContextClassLoader()
.getResourceAsStream(path);
}
}
涉及到的Location类
public class Location {
private String nodeName;
private double width;
private double height;
private double valueX;
private double valueY;
public String getNodeName() {
return nodeName;
}
public void setNodeName(String nodeName) {
this.nodeName = nodeName;
}
public double getWidth() {
return width;
}
public void setWidth(double width) {
this.width = width;
}
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}
public double getValueX() {
return valueX;
}
public void setValueX(double valueX) {
this.valueX = valueX;
}
public double getValueY() {
return valueY;
}
public void setValueY(double valueY) {
this.valueY = valueY;
}
@Override
public String toString() {
return "Location [height=" + height + ", nodeName=" + nodeName + ", valueX="
+ valueX + ", valueY=" + valueY + ", width=" + width + "]";
}
}
接下来进行dom4j的详细介绍
以下是相关操作:
一.Document对象相关
1.读取XML文件,获得document对象.
SAXReader reader = new SAXReader();
Document document = reader.read(new File("input.xml"));
SAXReader reader = new SAXReader();
Document document = reader.read(new File("input.xml"));
2.解析XML形式的文本,得到document对象.
String text = "<members></members>";
Document document = DocumentHelper.parseText(text);
3.主动创建document对象.
Document document = DocumentHelper.createDocument();
Element root = document.addElement("members");// 创建根节点
String text = "<members></members>";
Document document = DocumentHelper.parseText(text);
3.主动创建document对象.
Document document = DocumentHelper.createDocument();
Element root = document.addElement("members");// 创建根节点
二.节点相关
1.获取文档的根节点.
Element rootElm = document.getRootElement();
Element rootElm = document.getRootElement();
2.取得某节点的单个子节点.
Element memberElm=root.element("member");// "member"是节点名
Element memberElm=root.element("member");// "member"是节点名
3.取得节点的文字
String text=memberElm.getText();
也可以用:
String text=root.elementText("name");这个是取得根节点下的name字节点的文字.
String text=memberElm.getText();
也可以用:
String text=root.elementText("name");这个是取得根节点下的name字节点的文字.
4.取得某节点下名为"member"的所有字节点并进行遍历.
List nodes = rootElm.elements("member");
List nodes = rootElm.elements("member");
for (Iterator it = nodes.iterator(); it.hasNext();) {
Element elm = (Element) it.next();
// do something
}
Element elm = (Element) it.next();
// do something
}
5.对某节点下的所有子节点进行遍历.
for(Iterator it=root.elementIterator();it.hasNext();){
Element element = (Element) it.next();
// do something
}
for(Iterator it=root.elementIterator();it.hasNext();){
Element element = (Element) it.next();
// do something
}
6.在某节点下添加子节点.
Element ageElm = newMemberElm.addElement("age");
Element ageElm = newMemberElm.addElement("age");
7.设置节点文字.
ageElm.setText("29");
ageElm.setText("29");
8.删除某节点.
parentElm.remove(childElm);// childElm是待删除的节点,parentElm是其父节点
parentElm.remove(childElm);// childElm是待删除的节点,parentElm是其父节点
获取一个Element之后可以进行的相关操作：
attributue(String name) ：获取元素String值。
elementIterator() ：返回元素的所有子元素的Iterator迭代器。
elements() ：返回元素包含所有子元素List。
getParent() ：获取父元素Element。
getPath() ：获取自己的xpath。
detach() ：移除自己。
getName() ：获取节点的名称。
selectNodes(String xpathExpression) ：通过XPATH获取节点。
selectSingleNode(String xpathExpression) ：通过XPATH获取一个节点。
getDocument() ：作为一个Document返回。
三.属性相关
1.取得某节点下的某属性
Element root=document.getRootElement();
Attribute attribute=root.attribute("size");// 属性名name
2.取得属性的文字
String text=attribute.getText();
也可以用:
String text2=root.element("name").attributue("firstname");这个是取得根节点下name字节点的属性firstname的值.
3.遍历某节点的所有属性
Element root=document.getRootElement();
for(Iterator it=root.attributeIterator();it.hasNext();){
Attribute attribute = (Attribute) it.next();
String text=attribute.getText();
System.out.println(text);
}
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.设置某节点的属性和文字.
newMemberElm.addAttribute("name", "sitinspring");
5.设置属性的文字
Attribute attribute=root.attribute("name");
attribute.setText("sitinspring");
6.删除某属性
Attribute attribute=root.attribute("size");// 属性名name
root.remove(attribute);
四.将文档写入XML文件
1.文档中全为英文,不设置编码,直接写入的形式.
XMLWriter writer = new XMLWriter(new FileWriter("output.xml"));
writer.write(document);
writer.close();
2.文档中含有中文,设置编码格式写入的形式.
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("GBK"); // 指定XML编码
XMLWriter writer = new XMLWriter(new FileWriter("output.xml"),format);
writer.write(document);
writer.close();
五.字符串与XML的转换
1.将字符串转化为XML
String text = "<members> <member>sitinspring</member> </members>";
Document document = DocumentHelper.parseText(text);
2.将文档或节点的XML转化为字符串.
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();
六.使用XPath快速找到节点
读取的XML文档示例
<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
<name>MemberManagement</name>
<comment></comment>
<projects>
<project>PRJ1</project>
<project>PRJ2</project>
<project>PRJ3</project>
<project>PRJ4</project>
</projects>
<buildSpec>
<buildCommand>
<name>org.eclipse.jdt.core.javabuilder</name>
<arguments>
</arguments>
</buildCommand>
</buildSpec>
<natures>
<nature>org.eclipse.jdt.core.javanature</nature>
</natures>
</projectDescription>
使用XPath快速找到节点project.
public static void main(String[] args){
SAXReader reader = new SAXReader();
try{
Document doc = reader.read(new File("sample.xml"));
List projects=doc.selectNodes("/projectDescription/projects/project");
Iterator it=projects.iterator();
while(it.hasNext()){
Element elm=(Element)it.next();
System.out.println(elm.getText());
}
}
catch(Exception ex){
ex.printStackTrace();
}
}
public static void main(String[] args){
SAXReader reader = new SAXReader();
try{
Document doc = reader.read(new File("sample.xml"));
List projects=doc.selectNodes("/projectDescription/projects/project");
Iterator it=projects.iterator();
while(it.hasNext()){
Element elm=(Element)it.next();
System.out.println(elm.getText());
}
}
catch(Exception ex){
ex.printStackTrace();
}
}