如何使用SAX Java解析器读取注释文本
我希望使用Java中的SAX解析器仅读取XML文件中对象标记的注释 这是我的文件摘要:如何使用SAX Java解析器读取注释文本,java,xml,parsing,sax,Java,Xml,Parsing,Sax,我希望使用Java中的SAX解析器仅读取XML文件中对象标记的注释 这是我的文件摘要: <!-- Object Seed term: day, WikiTitle: day--> <object id="15155220" name="solar day, twenty-four hour period, 24-hour interval, mean solar day, twenty-four hours, si day, día, days, si days, day du
<!-- Object Seed term: day, WikiTitle: day-->
<object id="15155220" name="solar day, twenty-four hour period, 24-hour interval, mean solar day, twenty-four hours, si day, día, days, si days, day duration, day, civil day">
<!-- class: "calendar day" -->
<class id="15157041" name="calendar day, civil day"></class>
<!-- class: "unit of time" -->
<class id="15154774" name="time units, unit of time, time unit, units of time"></class>
<!-- class: "" -->
<class id="15113229" name="period of time, time period, period"></class>
<!-- class: "" -->
<class id="00000000" name="time"></class>
<genericPhysicalDescription>
<!-- hasPart: "" -->
<hasPart id="15228378" name="hour, time of day"></hasPart>
<!-- hasPart: "" -->
<hasPart id="15157225" name="day"></hasPart>
<!-- partOf: "calendar" -->
<partOf id="15173479" name="calendrics, calendar, dating style, calendarist, calendars, birthday calendar, calendar strip, secular calendar, calandar, agriculture calendar, calendar system, criminal calendar"></partOf>
<!-- partOf: "" -->
<partOf id="15206296" name="month"></partOf>
<!-- partOf: "" -->
<partOf id="15157225" name="day"></partOf>
</genericPhysicalDescription>
</object>
不支持阅读注释。它忽略了它们
允许您在解析时捕获注释。请参阅或上的示例
如果要将注释连接到紧跟其后的元素,还可以将注释传递给解析器并通过它跟踪其他XML内容。我修改了上面提到的代码,只打印对象
元素,前面紧跟着一条注释:
import org.xml.sax.*;
import org.xml.sax.ext.*;
import org.xml.sax.helpers.*;
import java.io.IOException;
public class Test implements LexicalHandler, ContentHandler {
private String lastComment;
public void startDTD(String name, String publicId, String systemId) throws SAXException {
}
public void endDTD() throws SAXException {
}
public void startEntity(String name) throws SAXException {
}
public void endEntity(String name) throws SAXException {
}
public void startCDATA() throws SAXException {
}
public void endCDATA() throws SAXException {
}
public void comment(char[] text, int start, int length) throws SAXException {
this.lastComment = new String(text, start, length).trim();
}
public void characters(char[] ch, int start, int length) {
}
public void endDocument() {
}
public void endElement(String uri, String localName, String qName) {
}
public void endPrefixMapping(String prefix) {
}
public void ignorableWhitespace(char[] ch, int start, int length) {
}
public void processingInstruction(String target, String data) {
}
public void setDocumentLocator(Locator locator) {
}
public void skippedEntity(String name) {
}
public void startDocument() {
}
public void startElement(String uri, String localName, String qName, Attributes atts) {
if (localName == "object") {
if (this.lastComment != null) {
System.out.println("Element object with comment found: \"" + this.lastComment + "\"");
this.lastComment = null;
}
} else {
this.lastComment = null;
}
}
public void startPrefixMapping(String prefix, String uri) {
}
public static void main(String[] args) {
Test test = new Test();
XMLReader parser;
try {
parser = XMLReaderFactory.createXMLReader();
} catch (SAXException ex1) {
try {
parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
} catch (SAXException ex2) {
return;
}
}
try {
parser.setProperty("http://xml.org/sax/properties/lexical-handler", test);
} catch (SAXNotRecognizedException e) {
System.out.println(e.getMessage());
return;
} catch (SAXNotSupportedException e) {
System.out.println(e.getMessage());
return;
}
parser.setContentHandler(test);
try {
parser.parse("test.xml");
} catch (SAXParseException e) {
System.out.println(e.getMessage());
} catch (SAXException e) {
System.out.println(e.getMessage());
} catch (IOException e) {
System.out.println(e.getMessage());
}
}
}
将此代码保存到“Test.java”,将XML内容保存到“Test.XML”。编译和执行后,它应提供以下输出:
$ javac Test.java
$ java Test
Element object with comment found: "Object Seed term: day, WikiTitle: day"
这段代码在使用parsingTrue之后开始读取所有注释e时,
LexicalHandler
不跟踪元素;您还需要将ContentHandler
设置到解析器,以跟踪额外的XML内容,并能够将注释和元素关联在一起。我更新了答案,只打印对象
元素的注释。