Detailed explanation of "Streaming Excel Reader" framework technical principles in the Java library

The "Streaming Excel Reader" framework in the Java library is a technology used to read Excel files.This framework can quickly and efficiently read large Excel files, and has less memory, which is suitable for processing a large amount of data. The principle of the Streaming Excel Reader framework is to resolve the Excel file into a series of events through an event -based model, and then use the event processor to handle these events.This event -driven model avoids the overhead of loading the entire Excel file to the memory, which can effectively reduce the amount of memory. Specifically, the Streaming Excel Reader framework is read through the following steps to read the Excel file: 1. Create ExcelReader Object: First of all, you need to create an ExcelReader object to read Excel files and handle the corresponding events. InputStream inputStream = new FileInputStream("path/to/excel.xlsx"); ExcelReader reader = new ExcelReader(inputStream); 2. Registration event processor: Next, you need to create an event processor to handle various events in the Excel file, such as starting the analysis of events, Sheet starting events, Sheet end events, starting events, ending events, etc.You can implement the ExcelReadreventListener interface, and rewrite the corresponding method to define the logic of the event processing. ExcelReaderEventListener eventListener = new MyEventListener(); reader.registerEventListener(eventListener); 3. Start parsing Excel file: Call the Read method of ExcelReader to start parsing the Excel file.During the analysis, Streaming Excel Reader triggers the corresponding event and passes the event to the registered event processor. reader.read(); 4. Processing event: Event processor will perform corresponding processing logic according to different event types.Through event objects, you can obtain information such as sheet, line index and cell content where the current event is located. public class MyEventListener implements ExcelReaderEventListener { @Override public void onStartParsing() { System.out.println ("Start Analysis Excel File"); } @Override public void onSheetStart(String sheetName, int sheetIndex) { System.out.println ("Start parsing sheet:" + sheetname); } @Override public void onRowStart(int rowIndex) { System.out.println ("Start parsing" + Rowindex + "line"); } @Override public void onCell(String cellValue, int columnIndex) { System.out.println ("Cell Content:" + Cellvalue); } // Other incident processing methods ... @Override public void onFinishParsing() { System.out.println ("Analysis excel file completion"); } } Through the above steps, the Streaming Excel Reader framework can read Excel files in a streaming manner and process it through the event drive model.This design enables the framework to effectively handle large Excel files and has an advantage in memory occupation.