Introduction to the incremental compiler framework in the Java class library

Introduction to the incremental compiler framework in the Java class library Overview: Incremental compilation refers to the re -compilation of the modified part of the source code, rather than the re -compilation of the entire code library.The incremental compiler framework in the Java library provides an effective method to handle the incremental compilation of the source code to improve the construction speed and performance of the Java application.This article will introduce the basic principles and usage methods of the incremental compiler framework in the Java library, and provide some Java code examples to help readers understand. 1. Basic principle of incremental compiler framework: The incremental compiler framework is based on the Java abstract syntax tree (AST) and the compiler API, and determine the modification range of the source code by comparing the AST before and after the comparative modification, and only compile these modified parts.The specific incremental compilation process is as follows: -We first, analyze the source code before and after modification to AST. -At, find the changing part by modifying AST before and after.These changes may include operations such as new, delete, and modification. -Finally, based on the changing part, only the modified code is re -compiled without re -compiling the entire code library. 2. How to use the incremental compiler framework: The incremental compiler framework in the Java class library usually provides some tool classes and APIs to simplify the use of incremental compilation.The following is a simple example code that demonstrates how to use the incremental compiler framework for incremental compilation: import javax.tools.JavaCompiler; import javax.tools.JavaFileObject; import javax.tools.StandardJavaFileManager; import javax.tools.ToolProvider; import java.util.Arrays; public class IncrementalCompilerExample { public static void main(String[] args) { // Obtain an incremental compiler instance JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); // Get the file manager StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null); // Set the source of the source code and the source file that needs to be compiled Iterable<? extends JavaFileObject> compilationUnits = fileManager.getJavaFileObjectsFromStrings(Arrays.asList("path/to/sourceFile1.java", "path/to/sourceFile2.java")); // Set the compilation parameter and target output directory Iterable<String> options = Arrays.asList("-d", "path/to/outputDirectory"); // Execute incremental compilation compiler.getTask(null, fileManager, null, options, null, compilationUnits).call(); // Close the file manager fileManager.close(); } } In the above sample code, we first obtained the default incremental compiler instance of the system, and set the source code path and source files that need to be compiled through the file manager.Next, only compile the modified source file and specify the compiled output directory.Finally, perform incremental compilation and output the compiled class file to the specified directory. Note: In actual use, the sample code needs to be appropriately modified and expanded according to the specific business needs. Summarize: This article introduces the basic principles and usage methods of the incremental compiler framework in the Java library, and provides a simple Java code example.By using an incremental compiler framework, it can significantly improve the construction speed and performance of the Java application, and reduce unnecessary repeated compilation.After reading this article, readers should have a preliminary understanding of the incremental compiler framework in the Java class library, and can conduct related development and application according to actual needs.