XML解析——Java中XML的四种解析方式

1.概念

2.代码

<!-- xml -->
<!-- https://mvnrepository.com/artifact/dom4j/dom4j -->
<dependency>
<groupId>dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>1.6.1</version>
</dependency>
<!-- xml -->

/**
* dom解析xml文件
* @param filePath
*/
public static void parseXml(String filePath){
//创建SAXReader对象
SAXReader reader = new SAXReader();
try {
//读取文件 转换成Document
Document document = reader.read(new File(filePath));
//获取根节点元素对象
Element root = document.getRootElement();
long s = System.currentTimeMillis();
getChildNodes(root);
long e = System.currentTimeMillis();
System.out.println(root.getName() + "节点元素遍历结束,耗时共:" + (e - s) + " ms");
} catch (DocumentException e) {
e.printStackTrace();
}
}

/**
* 遍历节点下的所有子节点和属性
* @param ele 元素节点
*/
private static void getChildNodes(Element ele){

String eleName = ele.getName();
System.out.println("开始遍历当前：" + eleName + "节点元素");
List<Attribute> attributes = ele.attributes();
for(Attribute attr : attributes){
System.out.println("name=" + attr.getName() + ",value=" + attr.getValue());
}

//同时迭代当前节点下面的所有子节点
//使用递归
Iterator<Element> iterator = ele.elementIterator();

if(!iterator.hasNext()){
String text = ele.getTextTrim();
System.out.println("text=" + text);
}

while(iterator.hasNext()){
Element e = iterator.next();
getChildNodes(e);
}
}

/**
* sax解析xml配置文件
* @param filePath
*/
public static void parseHandler(String filePath){
//创建SAXReader对象
SAXReader reader = new SAXReader();
reader.setDefaultHandler(new ElementHandler(){

@Override
public void onStart(ElementPath elementPath) {

}

@Override
public void onEnd(ElementPath elementPath) {
//获得当前节点
Element e = elementPath.getCurrent();
System.out.println(e.getName());
//记得从内存中移去
e.detach();
}
});
try {
reader.read(new BufferedInputStream(new FileInputStream(new File(filePath))));
} catch (DocumentException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}

}

public static void writeXml(String filePath, Document doc){
// 设置XML文档格式
OutputFormat outputFormat = OutputFormat.createPrettyPrint();
// 设置XML编码方式,即是用指定的编码方式保存XML文档到字符串(String),这里也可以指定为GBK或是ISO8859-1
outputFormat.setEncoding("UTF-8");
//是否生产xml头
outputFormat.setSuppressDeclaration(true);
//设置是否缩进
outputFormat.setIndent(true);
//以四个空格方式实现缩进
outputFormat.setIndent("    ");
//设置是否换行
outputFormat.setNewlines(true);
XMLWriter out = null;
try{
out = new XMLWriter(new FileWriter(new File(filePath)), outputFormat);
out.write(doc);
}catch(IOException e){
e.printStackTrace();
}
finally{
IOUtils.close(out);
}
}

String filePath = "src/main/resources/xml/test.xml";
File file = new File(filePath);
if(!file.exists()){
long s = System.currentTimeMillis();
Document doc = DocumentHelper.createDocument();
Element root = doc.addElement("root");
for(int i = 0; i <= 10000000; i++){
Element testElement = DocumentHelper.createElement("eleTest");
testElement.addAttribute("name", "testEle");
testElement.addText("this is another text");
root.add(testElement);
}
writeXml("src/main/resources/xml/test.xml", doc);
long e = System.currentTimeMillis();
System.out.println("共耗时:" + (e - s) + "ms");
}
//        parseXml(filePath);
parseHandler(filePath);

源码地址请移步 https://github.com/followwwind/javautils[/code]