是否可以从startElement函数中的
XML文件中获取元素的内容,该函数是SAX处理程序的覆盖函数？
以下是规格.
1)XML文件
<employees>
<employee id="111">
<firstName>Rakesh</firstName>
<lastName>Mishra</lastName>
<location>Bangalore</location>
</employee>
<employee id="112">
<firstName>John</firstName>
<lastName>Davis</lastName>
<location>Chennai</location>
</employee>
<employee id="113">
<firstName>Rajesh</firstName>
<lastName>Sharma</lastName>
<location>Pune</location>
</employee>
</employees>
2)startElement函数
@Override
public void startElement(String uri,String localName,String qName,Attributes attributes) throws SAXException {
.......code in here..........
}
3)预期结果
element name : employee attribute name : id attribute value: 111 firstName : Rakesh lastName : Mishra location : Bangalore element name : employee attribute name : id attribute value: 112 firstName : John lastName : Davis location : Chennai element name : employee attribute name : id attribute value: 113 firstName : Rajesh lastName : Sharma location : Pune
您可以在startElement和endElement中获取元素的名称.您还可以在startElement中获取属性.您应该以字符形式获得的值.
原文链接：https://www.f2er.com/xml/292106.html以下是如何使用ContentHandler获取元素值的一个非常基本的示例：
public class YourHandler extends DefaultHandler {
boolean inFirstNameElement = false;
public class startElement(....) {
if(qName.equals("firstName") {
inFirstNameElement = true;
}
}
public class endElement(....) {
if(qName.equals("firstName") {
inFirstNameElement = false;
}
}
public class characters(....) {
if(inFirstNameElement) {
// do something with the characters in the <firstName> element
}
}
}
如果您有一个简单的示例,则为每个标记设置布尔标记即可.如果您有一个更复杂的场景,您可能更喜欢使用元素名称作为键将标志存储在映射中,或者甚至创建一个或多个映射到XML的Employee类,并在每次< employee>时实例化它们.在startElement中找到,填充其属性,并将其添加到endElement中的Collection.
这是一个完整的ContentHandler示例,适用于您的示例文件.我希望它可以帮助你开始：
public class SimpleHandler extends DefaultHandler {
class Employee {
public String firstName;
public String lastName;
public String location;
public Map<String,String> attributes = new HashMap<>();
}
boolean isFirstName,isLastName,isLocation;
Employee currentEmployee;
List<Employee> employees = new ArrayList<>();
@Override
public void startElement(String uri,Attributes atts) throws SAXException {
if(qName.equals("employee")) {
currentEmployee = new Employee();
for(int i = 0; i < atts.getLength(); i++) {
currentEmployee.attributes.put(atts.getQName(i),atts.getValue(i));
}
}
if(qName.equals("firstName")) { isFirstName = true; }
if(qName.equals("lastName")) { isLastName = true; }
if(qName.equals("location")) { isLocation = true; }
}
@Override
public void endElement(String uri,String qName)
throws SAXException {
if(qName.equals("employee")) {
employees.add(currentEmployee);
currentEmployee = null;
}
if(qName.equals("firstName")) { isFirstName = false; }
if(qName.equals("lastName")) { isLastName = false; }
if(qName.equals("location")) { isLocation = false; }
}
@Override
public void characters(char[] ch,int start,int length) throws SAXException {
if (isFirstName) {
currentEmployee.firstName = new String(ch,start,length);
}
if (isLastName) {
currentEmployee.lastName = new String(ch,length);
}
if (isLocation) {
currentEmployee.location = new String(ch,length);
}
}
@Override
public void endDocument() throws SAXException {
for(Employee e: employees) {
System.out.println("Employee ID: " + e.attributes.get("id"));
System.out.println(" First Name: " + e.firstName);
System.out.println(" Last Name: " + e.lastName);
System.out.println(" Location: " + e.location);
}
}
}
