How to use the@Babel/Types framework in the Java class library for syntax conversion
How to use the@Babel/Types framework in the Java class library for syntax conversion
@Babel/Types is a framework for syntax conversion in JavaScript code. Abstract syntax trees (AST) that can easily operate JavaScript code in compilation, transcoding and other code processing.This article will introduce how to use the@Babel/Types framework in the Java library for syntax conversion, and provide related Java code examples.
1. Introduce dependency library
Add the following dependency library to the pom.xml file of the Java project:
<dependency>
<groupId>com.github.japgolly.javaparser</groupId>
<artifactId>javaparser-core</artifactId>
<version>3.26.0</version>
</dependency>
<dependency>
<groupId>org.webjars.npm</groupId>
<artifactId>babel-types</artifactId>
<version>7.15.0</version>
</dependency>
2. Analyze JavaScript code
Use JavaParser library to analyze the JavaScript code and convert it into an abstract syntax tree:
import com.github.javaparser.JavaParser;
import com.github.javaparser.ParseProblemException;
import com.github.javaparser.ast.CompilationUnit;
public class JavaScriptParser {
public CompilationUnit parse(String sourceCode) throws ParseProblemException {
return JavaParser.parse(sourceCode);
}
}
3. Perform syntax conversion
Use the@Babel/Types framework for syntax conversion operation. You can add, delete, modify or replace the AST node as needed:
import com.github.javaparser.ast.CompilationUnit;
import com.github.japgolly.javaparser.Parser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.webjars.babeltypes.BabelTypes;
import.org.webjars.babeltypes.types.BasicType;
public class JavaScriptTransformer {
private static final Logger LOGGER = LoggerFactory.getLogger(JavaScriptTransformer.class);
private static final BabelTypes babelTypes = new BabelTypes();
public String transform(String sourceCode) {
CompilationUnit cu = new JavaScriptParser().parse(sourceCode);
// Perform syntax conversion operations
BasicType newExpression = babelTypes.newExpression("Identifier", "Foo");
cu.findAll(MethodCallExpr.class).forEach(node -> {
if (node.getName().getIdentifier().equals("bar")) {
node.replace(newExpression);
}
});
return cu.toString();
}
}
In the above example, we analyzed the JavaScript code as an abstract syntax tree, and used the new expression method of the Babel-Types framework to create a new AST node, and replaced it with all methods called "Bar" to call the node.You can find and modify the AST node according to actual needs.
4. Use conversion results
In your Java project, you can use the above conversion code and get the conversion JavaScript code result:
public class Main {
public static void main(String[] args) {
String sourceCode = "function foo() {
bar();
baz();
}
";
String transformedCode = new JavaScriptTransformer().transform(sourceCode);
System.out.println(transformedCode);
}
}
Run the Main class mentioned above, and the JavaScript code after the grammatical conversion will be output:
script
function foo() {
Foo();
baz();
}
Through the above steps, you can use the@Babel/Types framework in the Java library for JavaScript syntax conversion operation.As a result, JavaScript code can be easily added, deleted, modified or replaced with syntax.
