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This article will explain in detail about the common XML parsing under the Android platform. The editor thinks it is very practical, so I share it with you as a reference. I hope you can get something after reading this article.

XML is widely used in all kinds of development, and Android is no exception. As an important role in carrying data, how to read and write XML has become an important skill in Android development. Today, let me introduce several common methods of XML parsing and creation under the Android platform.

In Android, the common XML parsers are SAX parser, DOM parser and PULL parser. Next, I'll give you a detailed introduction.

SAX parser:

The SAX (Simple API for XML) parser is an event-based parser, and its core is the event handling mode, which mainly works around the event source and event handler. When an event is generated by an event source, the corresponding processing method of the event handler is called, and an event can be processed. When the event source calls a specific method in the event handler, it also passes the state information of the corresponding event to the event handler, so that the event handler can determine its behavior according to the event information provided.

The advantage of SAX parser is that it parses quickly and takes up less memory. Very suitable for use in Android mobile devices.

DOM parser:

A DOM is a collection of nodes or pieces of information based on a tree structure that allows developers to use DOM API to traverse the XML tree and retrieve the data they need. Analyzing this structure usually requires loading the entire document and constructing a tree structure before you can retrieve and update node information.

Because DOM is stored in a tree structure in memory, retrieval and update are more efficient. But for very large documents, parsing and loading the entire document can be resource-consuming.

PULL parser:

The PULL parser operates in an event-based pattern similar to SAX. The difference is that in the process of PULL parsing, we need to get the generated event ourselves and do the corresponding action, instead of executing our code in the way that an event is triggered by the processor in SAX. PULL parser is small and light, fast and easy to use, so it is very suitable for use in Android mobile devices. PULL parser is also used in Android system when parsing all kinds of XML.

In Android, the first push is of course the pull parser. PULL parser is compact, fast and easy to use, so it is very suitable for use in Android mobile devices. PULL parser is also used in Android system when parsing all kinds of XML. Android officially recommends developers to use Pull parsing technology. Pull parsing technology is an open source technology developed by third parties, and it can also be applied to JavaSE development.

How PULL works:

XML pull provides the start and end elements. When an element starts, you can call parser.nextText to extract all character data from the XML document. When parsing to the end of a document, the EndDocument event is automatically generated.

Commonly used XML pull interfaces and classes:

XmlPullParser: this parser is an interface to the parsing function defined in org.xmlpull.v1.

XmlSerializer: it is an interface that defines the sequence of XML information sets.

XmlPullParserFactory: this class is used to create a XML Pull parser in XMPULL V1 API.

XmlPullParserException: throw errors related to a single XML pull parser.

The PULL parser operates in an event-based pattern similar to SAX.

The difference is that numbers are returned during PULL parsing, and we need to get the generated event ourselves and do the corresponding action, instead of executing our code in a way that the processor triggers an event like SAX:

The declaration that reads xml returns START_DOCUMENT; ends and returns END_DOCUMENT; the start tag returns START_TAG

The closing tag returns END_TAG; text and returns TEXT.

Finally, the three parsing techniques are compared and summarized.

For Android mobile devices, because the resources of the devices are precious and the memory is limited, we need to choose a suitable technology to parse XML, which is helpful to improve the speed of access.

When DOM processes the XML file, it parses the XML file into a tree structure and puts it into memory for processing. When the XML file is small, we can choose DOM because it is simple and intuitive.

SAX uses events as the mode of parsing XML files. It converts XML files into a series of events, and different event handlers decide how to handle them. When the XML file is large, it is reasonable to choose SAX technology. Although the amount of code is a bit large, it does not need to load all the XML files into memory. This is more efficient for limited Android memory, and Android provides a traditional SAX usage and a convenient SAX wrapper. Using the Xml class is easier than using SAX.

Instead of listening to the end of the element as SAX parsing does, XML pull parsing does most of the processing at the beginning. This facilitates early reading of XML files and greatly reduces parsing time, which is especially important for mobile devices with diffuse connection speeds. The XML Pull parser is a more efficient approach for XML documents that are large but require only a portion of the document.

This is the end of this article on "what are the common XML parsing under the Android platform?" I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it out for more people to see.

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