Analysis of the core technical principles of Table/IO CSV SUPPORT framework in Java

Table/IO CSV Support framework is an important tool for operating CSV files in the Java class library.This article will analyze the core technical principles of the framework to help readers understand and use this powerful tool. 1. Introduction to CSV files CSV (COMMA-SEPARATED VALUES) is a commonly used text file format that is used to store and exchange a large number of structured data.The CSV file consists of multiple lines. Each row represents a record. Different fields are separated by comma or other separators.CSV files can be edited and viewed using electronic table software such as Excel, and can also read and write through programming languages. 2. Table/IO CSV SUPPORT framework Table/IO CSV Support framework is an important tool for reading and writing and processing CSV files in the Java class library.It provides a set of simple and flexible APIs that allow developers to easily read and write CSV files and perform various data conversion and processing operations. 3. Core technical principles The core technical principles of Table/IO CSV SUPPORT framework can be divided into the following aspects: -The read of CSV files: The framework provides a CSVReader class, which can read and analyze the CSV file into Java objects.During the reading process, the boundary of each field is determined according to the separation symbols and quotes of the CSV file. -CSV file writing: The framework provides a CSVWriter class, which can write the Java object into the CSV file one by one.During the writing process, the contents of each field are generated according to the separation symbols and quotes of the CSV file. -A data conversion: During the reading and writing process, the framework supports the data in the CSV file to the Java object and the data of the Java object into the data in the CSV file.Developers can realize various complex data conversion operations by realizing custom data converters. -A data processing: In addition to the basic reading and writing functions, the framework also provides some commonly used data processing operations, such as sorting, filtering, and grouping.Developers can complete these operations by calling the API provided by the framework to simplify the development process. Here are some examples of examples to show the basic usage of Table/IO CSV Support framework: Read the CSV file: Reader reader = new FileReader("data.csv"); CSVReader csvReader = new CSVReader(reader); String [] header = csvreader.readnext (); // Read the header List <string []> rows = csvreader.readall (); // Read the data csvReader.close(); reader.close(); Write to CSV file: Writer writer = new FileWriter("data.csv"); CSVWriter csvWriter = new CSVWriter(writer); String[] header = {"Name", "Age", "Email"}; String[] row1 = {"John", "25", "john@example.com"}; String[] row2 = {"Alice", "30", "alice@example.com"}; csvwriter.writenext (header); // Write into the header csvwriter.writenext (row1); // Write data csvWriter.writeNext(row2); csvWriter.close(); writer.close(); Data conversion and processing: // Custom data converter class CustomConverter implements Converter<String, Integer> { @Override public Integer convert(String value) { return Integer.parseInt(value); } } Reader reader = new FileReader("data.csv"); CSVReader csvReader = new CSVReader(reader); Table<String, Integer, String> table = csvReader.readAll().stream() .collect(Collectors.toTable( row -> row[0], // Key列 row -> new CustomConverter().convert(row[1]), // Value列 ROW-> ROW [2] // Data column )); csvReader.close(); reader.close(); // Sort the data Table<String, Integer, String> sortedTable = table.sortByRowKeys() .sortByColumnKeys(); // Filter data Table<String, Integer, String> filteredTable = table.column("Age") .removeIf(age -> age < 30); // Group data Table<String, Integer, Collection<String>> groupedTable = table.column("Name") .group(); // Output CSV file Writer writer = new FileWriter("output.csv"); CSVWriter csvWriter = new CSVWriter(writer); csvWriter.writeAll(sortedTable.values()); csvWriter.close(); writer.close(); 4. Summary Table/IO CSV SUPPORT framework is a powerful tool for reading and writing and processing CSV files in Java. It provides simple and flexible APIs, so that developers can easily operate CSV files.By understanding and applying the core technical principles of the framework, developers can better use CSV files for data processing and exchange.