How to select multiple java file, generate toString() for all fields in each class in bulk

VirtualFile[] virtualFiles = e.getData(CommonDataKeys.VIRTUAL_FILE_ARRAY);
for (VirtualFile virtualFile : virtualFiles) {
    PsiFile psiFile = PsiManager.getInstance(e.getProject()).findFile(virtualFile);
    final PsiClass psiClass = PsiTreeUtil.findChildOfAnyType(psiFile.getOriginalElement(), PsiClass.class);
    new WriteCommandAction.Simple(psiClass.getProject(), psiClass.getContainingFile()) {
        @Override
        protected void run() throws Throwable {
            //删除已存在的方法
            //没有文档，经测试，猜测，第二个参数是表示查找范围是否包含父类
            PsiMethod[] pms = psiClass.findMethodsByName("toString", false);
            if (pms.length > 0) {
                for (PsiMethod pm : pms) {
                    pm.delete();
                }
            }
            generateToStringImpl(psiClass);
        }
    }.execute();
}