请写一个java代码格式化工具

以下是一个简单的 Java 代码格式化工具，使用了 Java 编译器的 API：

import com.sun.source.util.TreePath;
import com.sun.source.util.TreePathScanner;
import com.sun.tools.javac.api.JavacTrees;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.List;

import javax.tools.JavaFileObject;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;

public class JavaCodeFormatter {

    private static final String INDENTATION = "    "; // 4 spaces

    public static void main(String[] args) throws IOException {
        Path filePath = Path.of("path/to/java/file.java");
        String source = Files.readString(filePath, StandardCharsets.UTF_8);

        Context context = new Context();
        JavaFileObject sourceFile = JavacTool
                .create().getTask(null, null, null, null, null,
                        List.of(new SourceFile(sourcePath.toString())), context)
                .call()
                .iterator()
                .next()
                .getSourceFile();

        JavacTrees trees = JavacTrees.instance(context);
        JCCompilationUnit compilationUnit = (JCCompilationUnit) trees
                .parse(sourceFile);

        TreePathScanner<Void, Void> scanner = new TreePathScanner<>() {

            private int indentationLevel = 0;

            @Override
            public Void visitVariable(JCVariableDecl variableDecl, Void aVoid) {
                variableDecl.mods.annotations = variableDecl.mods.annotations.stream()
                        .sorted((a, b) -> a.toString().compareToIgnoreCase(b.toString()))
                        .collect(Collectors.toList());

                return super.visitVariable(variableDecl, aVoid);
            }

            @Override
            public Void visitClassDef(JCTree.JCClassDecl classDecl, Void aVoid) {
                printIndented("class " + classDecl.getSimpleName());

                if (classDecl.getExtendsClause() != null) {
                    printIndented("extends " + classDecl.getExtendsClause());
                }

                if (!classDecl.getInterfaces().isEmpty()) {
                    printIndented("implements " + classDecl.getInterfaces());
                }

                printIndented("{");
                indentationLevel++;

                List<JCTree> members = classDecl.getMembers();
                for (int i = 0; i < members.size(); i++) {
                    JCTree member = members.get(i);
                    if (member instanceof JCVariableDecl) {
                        printIndented(((JCVariableDecl) member).toString() + ";");
                    } else {
                        printIndented(member.toString());
                    }
                }

                indentationLevel--;
                printIndented("}");

                return super.visitClassDef(classDecl, aVoid);
            }

            private void printIndented(String string) {
                System.out.println(INDENTATION.repeat(indentationLevel) + string);
            }
        };

        TreePath path = trees.getPath(compilationUnit);
        scanner.scan(path, null);
    }
}

这个代码格式化工具会读取指定的 Java 源码文件，使用 Java 编译器的 API 解析和遍历语法树，然后格式化输出。这个示例代码会把变量的注解按字母顺序排序，并且使用 4 个空格缩进。