python 的 javalang 库【2】

在 前文 以及 参考文章1、参考文章2 的基础上，继续分析以及 Demo 演示

ast.py
class MetaNode(type)
class Node(object)
def walk_tree(root)
def dump(ast, file)
def load(file)

• Node.__ iter__ 即 javalang.ast.walk_tree(Node)
• 简单的持久化由 pickle 库提供的 dump 和 load 实现。

import pickle

def dump(ast, file):
    pickle.dump(ast, file)
    
def load(file):
    return pickle.load(file)

抽象语法树 DEMO

示例 Java 代码

#Test.java
public class Clazz{
   
   
    private static DateFormat format = new SimpleDateFormat("yyyy/MM/dd");

    public Date method(String date){
   
   
        return format.parse(date);
    }
}

import javalang

f = open("Test.java", "r")
tree = javalang.parse.parse(f.read())

for path, node in tree:
    print(path, node)

for path, node in tree:
    print(node)
    #直接获取类名
    #print(node.__class__.__name__)
    
# filter 过滤
print(type(tree.filter(javalang.tree.Declaration)), tree.filter(javalang.tree.Declaration))
for path, node in tree.filter(javalang.tree.Declaration):
    print(node)
    
# __init__ 初始化
print(type(tree.__init__(imports="csdn.Attribute47.com")), tree)
# children 返回子信息list
print(type(tree.children), tree.children)
# __repr__ 转换为str
print(type(tree.__repr__()), tree.__repr__())
# __equals__ 相同判断
print(type(tree.__equals__(tree)), tree.__equals__(tree))
# __iter__ 返回walk_tree
print(type(tree.__iter__()), tree.__iter__())

#省略节点内参数
() CompilationUnit()
(CompilationUnit(), [ClassDeclaration()]) ClassDeclaration()
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()]) FieldDeclaration()
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()], FieldDeclaration()) ReferenceType()
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()], FieldDeclaration(), [VariableDeclarator()]) VariableDeclarator()
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()], FieldDeclaration(), [VariableDeclarator()], VariableDeclarator()) ClassCreator())
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()], FieldDeclaration(), [VariableDeclarator()], VariableDeclarator(), ClassCreator())) ReferenceType()
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()], FieldDeclaration(), [VariableDeclarator()], VariableDeclarator(), ClassCreator()), [Literal()]) Literal()
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()]) MethodDeclaration()
(CompilationUnit(), [ClassDeclaration()], ClassDeclaration(), [FieldDeclaration(), MethodDeclaration()