public void prepare()

in txtfilewriter/src/main/java/com/alibaba/datax/plugin/writer/txtfilewriter/TxtFileWriter.java [95:199]
99 lines of code
16 McCabe index (conditional complexity)

        public void prepare() {
            String path = this.writerSliceConfig.getString(Key.PATH);
            String fileName = this.writerSliceConfig
                    .getString(com.alibaba.datax.plugin.unstructuredstorage.writer.Key.FILE_NAME);
            String writeMode = this.writerSliceConfig
                    .getString(com.alibaba.datax.plugin.unstructuredstorage.writer.Key.WRITE_MODE);
            // truncate option handler
            if ("truncate".equals(writeMode)) {
                LOG.info(String.format(
                        "由于您配置了writeMode truncate, 开始清理 [%s] 下面以 [%s] 开头的内容",
                        path, fileName));
                File dir = new File(path);
                // warn:需要判断文件是否存在，不存在时，不能删除
                try {
                    if (dir.exists()) {
                        // warn:不要使用FileUtils.deleteQuietly(dir);
                        FilenameFilter filter = new PrefixFileFilter(fileName);
                        File[] filesWithFileNamePrefix = dir.listFiles(filter);
                        for (File eachFile : filesWithFileNamePrefix) {
                            LOG.info(String.format("delete file [%s].",
                                    eachFile.getName()));
                            FileUtils.forceDelete(eachFile);
                        }
                        // FileUtils.cleanDirectory(dir);
                    }
                } catch (NullPointerException npe) {
                    throw DataXException
                            .asDataXException(
                                    TxtFileWriterErrorCode.Write_FILE_ERROR,
                                    String.format("您配置的目录清空时出现空指针异常 : [%s]",
                                            path), npe);
                } catch (IllegalArgumentException iae) {
                    throw DataXException.asDataXException(
                            TxtFileWriterErrorCode.SECURITY_NOT_ENOUGH,
                            String.format("您配置的目录参数异常 : [%s]", path));
                } catch (SecurityException se) {
                    throw DataXException.asDataXException(
                            TxtFileWriterErrorCode.SECURITY_NOT_ENOUGH,
                            String.format("您没有权限查看目录 : [%s]", path));
                } catch (IOException e) {
                    throw DataXException.asDataXException(
                            TxtFileWriterErrorCode.Write_FILE_ERROR,
                            String.format("无法清空目录 : [%s]", path), e);
                }
            } else if ("append".equals(writeMode)) {
                LOG.info(String
                        .format("由于您配置了writeMode append, 写入前不做清理工作, [%s] 目录下写入相应文件名前缀  [%s] 的文件",
                                path, fileName));
            } else if ("nonConflict".equals(writeMode)) {
                LOG.info(String.format(
                        "由于您配置了writeMode nonConflict, 开始检查 [%s] 下面的内容", path));
                // warn: check two times about exists, mkdirs
                File dir = new File(path);
                try {
                    if (dir.exists()) {
                        if (dir.isFile()) {
                            throw DataXException
                                    .asDataXException(
                                            TxtFileWriterErrorCode.ILLEGAL_VALUE,
                                            String.format(
                                                    "您配置的path: [%s] 不是一个合法的目录, 请您注意文件重名, 不合法目录名等情况.",
                                                    path));
                        }
                        // fileName is not null
                        FilenameFilter filter = new PrefixFileFilter(fileName);
                        File[] filesWithFileNamePrefix = dir.listFiles(filter);
                        if (filesWithFileNamePrefix.length > 0) {
                            List<String> allFiles = new ArrayList<String>();
                            for (File eachFile : filesWithFileNamePrefix) {
                                allFiles.add(eachFile.getName());
                            }
                            LOG.error(String.format("冲突文件列表为: [%s]",
                                    StringUtils.join(allFiles, ",")));
                            throw DataXException
                                    .asDataXException(
                                            TxtFileWriterErrorCode.ILLEGAL_VALUE,
                                            String.format(
                                                    "您配置的path: [%s] 目录不为空, 下面存在其他文件或文件夹.",
                                                    path));
                        }
                    } else {
                        boolean createdOk = dir.mkdirs();
                        if (!createdOk) {
                            throw DataXException
                                    .asDataXException(
                                            TxtFileWriterErrorCode.CONFIG_INVALID_EXCEPTION,
                                            String.format(
                                                    "您指定的文件路径 : [%s] 创建失败.",
                                                    path));
                        }
                    }
                } catch (SecurityException se) {
                    throw DataXException.asDataXException(
                            TxtFileWriterErrorCode.SECURITY_NOT_ENOUGH,
                            String.format("您没有权限查看目录 : [%s]", path));
                }
            } else {
                throw DataXException
                        .asDataXException(
                                TxtFileWriterErrorCode.ILLEGAL_VALUE,
                                String.format(
                                        "仅支持 truncate, append, nonConflict 三种模式, 不支持您配置的 writeMode 模式 : [%s]",
                                        writeMode));
            }
        }