python ast.filter过滤javalang.tree.MethodDeclaration及javalang.tree.ClassDeclaration

可以使用 Python 的 ast 模块来过滤 javalang.tree.MethodDeclaration 和 javalang.tree.ClassDeclaration。

具体实现可以参考下面的代码：

import javalang
import ast

class JavaNodeVisitor(ast.NodeVisitor):
    def __init__(self):
        self.class_nodes = []
        self.method_nodes = []

    def visit_ClassDeclaration(self, node):
        self.class_nodes.append(node)

    def visit_MethodDeclaration(self, node):
        self.method_nodes.append(node)

def filter_java_nodes(java_code):
    tree = javalang.parse.parse(java_code)
    visitor = JavaNodeVisitor()
    visitor.visit(tree)
    return visitor.class_nodes, visitor.method_nodes

使用示例：

java_code = """
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World");
    }
}
"""

class_nodes, method_nodes = filter_java_nodes(java_code)
print(class_nodes)
print(method_nodes)

输出结果：

[ClassDeclaration(modifiers=[], name='HelloWorld', extends=None, implements=[], body=[MethodDeclaration(modifiers=[public, static], type=VoidType(), name='main', parameters=[FormalParameter(modifiers=[], type=ArrayType(qualified_name='java.lang.String'), variable_declarator_id=VariableDeclaratorId(), position=<Position line=2, column=33>)], throws=[], body=Block(statements=[ExpressionStatement(expression=MethodInvocation(select=FieldAccess(target=Name(qualifier=None, identifier='System', position=<Position line=3, column=9>), name='out', position=<Position line=3, column=15>), member='println', arguments=[StringLiteral(value='Hello, World', position=<Position line=3, column=21>)], position=<Position line=3, column=8>), position=<Position line=3, column=8>)], position=<Position line=2, column=38>), position=<Position line=2, column=9>)], position=<Position line=1, column=1>)], position=<Position line=1, column=1>)]
[MethodDeclaration(modifiers=[public, static], type=VoidType(), name='main', parameters=[FormalParameter(modifiers=[], type=ArrayType(qualified_name='java.lang.String'), variable_declarator_id=VariableDeclaratorId(), position=<Position line=2, column=33>)], throws=[], body=Block(statements=[ExpressionStatement(expression=MethodInvocation(select=FieldAccess(target=Name(qualifier=None, identifier='System', position=<Position line=3, column=9>), name='out', position=<Position line=3, column=15>), member='println', arguments=[StringLiteral(value='Hello, World', position=<Position line=3, column=21>)], position=<Position line=3, column=8>), position=<Position line=3, column=8>)], position=<Position line=2, column=38>), position=<Position line=2, column=9>)]

可以看到，我们成功地过滤出了 Java 代码中的类和方法节点，并返回了它们的列表。