重复 for 循环但结果不同。我如何删除重复代码

Question

我有重复的 for 循环。一个函数打印到屏幕，另一个函数写入文件。由于 for 循环相同，但结果不同，我很难找到避免重复的方法。看来这个问题接近于回答我自己的问题；然而，据说当打印到屏幕上时，它们可能会出现一些重复，我不确定这里是否是这种情况。如何从我的代码中删除重复项private static void printToFile(char space, char hash, int spaceCount, int hashCount){    try (PrintWriter outFile = new PrintWriter(new FileWriter("output.txt"))) {        for (int i = 0; i < 8; i++) {            outFile.write(String.valueOf(marioStepCreator(space, spaceCount)));            outFile.flush();            outFile.write(String.valueOf(marioStepCreator(hash, hashCount)));            outFile.flush();            outFile.write("\n");            hashCount++;            spaceCount--;        }    } catch(FileNotFoundException e) {        e.getCause();    } catch (IOException e) {        e.printStackTrace();    }}private static void printToScreen(char space, char hash, int spaceCount, int hashCount){    for (int i = 0; i < 8; i++) {        System.out.print(marioStepCreator(space, spaceCount));        System.out.print(marioStepCreator(hash, hashCount));        System.out.println();        hashCount++;        spaceCount--;    }}

Answer 1

由于您已经在使用PrintWriter用于写入文件，因此将通用代码移至辅助方法：

private static void printToFile(char space, char hash, int spaceCount, int hashCount){

    try (PrintWriter outFile = new PrintWriter(new FileWriter("output.txt"))) {

        printToWriter(outFile, space, hash, spaceCount, hashCount);

    } catch(FileNotFoundException e) {

        e.getCause();

    } catch (IOException e) {

        e.printStackTrace();

    }

}

private static void printToScreen(char space, char hash, int spaceCount, int hashCount){

    PrintWriter out = new PrintWriter(System.out);

    printToWriter(out, space, hash, spaceCount, hashCount);

    out.flush(); // Do not close

}

private static void printToWriter(PrintWriter out, char space, char hash, int spaceCount, int hashCount){

    for (int i = 0; i < 8; i++) {

        out.print(marioStepCreator(space, spaceCount));

        out.println(marioStepCreator(hash, hashCount));

        hashCount++;

        spaceCount--;

    }

}

当然，您真的需要修复printToFile方法中的异常处理。

由于您使用 try-with-resources 立即关闭文件编写器，因此无需刷新输出。然而，包装必须被刷新，以防它正在缓冲，但不应该被关闭，PrintWriter因为System.out我们不想关闭System.out。

Answer 2

您可以隔离 for 循环以生成一个 String 消息，该消息可以使用 writer 或 System.out.println 在一行中打印；

private static void printToFile(char space, char hash, int spaceCount, int hashCount){

    try (PrintWriter outFile = new PrintWriter(new FileWriter("output.txt"))) {

        outFile.write(printMessage(space, hash, spaceCount, hashCount));

        outFile.flush();        

    } catch(FileNotFoundException e) {

        e.getCause();

    } catch (IOException e) {

        e.printStackTrace();

    }

}

private static void printToScreen(char space, char hash, int spaceCount, int hashCount){

    System.out.print(printMessage(space, hash, spaceCount, hashCount));

}

private static String printMessage(char space, char hash, int spaceCount, int hashCount) {

    String message = "";

    for (int i = 0; i < 8; i++) {

        message += marioStepCreator(space, spaceCount) + marioStepCreator(hash, hashCount) + "\n";

        hashCount++;

        spaceCount--;

    }

    return message;

}

Answer 3

你也可以尝试做这样的事情 -

private static List<String> getOutput(char space, char hash, int spaceCount, int hashCount) {

    List<String> output = new ArrayList<>();

    for (int i = 0; i < 8; i++) {

        output.add(String.valueOf(marioStepCreator(space, spaceCount)));

        output.add(String.valueOf(marioStepCreator(hash, hashCount)));

        hashCount++;

        spaceCount--;

    }

    return output;

}

private static void printToFileAndScreen(char space, char hash, int spaceCount, int hashCount) {

    try (PrintWriter outFile = new PrintWriter(new FileWriter("output.txt"))) {

        getOutput(space, hash, spaceCount, hashCount).stream().forEach(s ->

        {

            outFile.write(s);

            outFile.flush();

        });

    } catch (FileNotFoundException e) {

        e.getCause();

    } catch (IOException e) {

        e.printStackTrace();

    }

}

private static void printToScreen(char space, char hash, int spaceCount, int hashCount) {

    getOutput(space, hash, spaceCount, hashCount).stream().forEach(s -> System.out.println(s));

}

通过这种方式，您可以将主要业务逻辑与输出消费者分开。此外，您可以为不同的编写器实现和连接具有“write()”方法的接口。这种方式很容易编写测试用例。

Answer 4

这个怎么样：

private static void printToFileAndScreen(char space, char hash, int spaceCount, int hashCount){

    try (PrintWriter outFile = new PrintWriter(new FileWriter("output.txt"))) {

        for (int i = 0; i < 8; i++) {

            String spaceString = String.valueOf(marioStepCreator(space, spaceCount));

            String hashString = String.valueOf(marioStepCreator(hash, hashCount));

            outFile.write(spaceString);

            outFile.write(hashString);

            outFile.write("\n");

            outFile.flush();

            System.out.print(spaceString);

            System.out.print(hashString);

            System.out.println();

            hashCount++;

            spaceCount--;

        }

    } catch(FileNotFoundException e) {

        e.getCause();

    } catch (IOException e) {

        e.printStackTrace();

    }

}

Answer 5

这个怎么样：

private static void printToFile(char space, char hash, int spaceCount, int hashCount) {

    try (PrintWriter outFile = new PrintWriter(new FileWriter("output.txt"))) {

        loop(spaceCount, hashCount, (sCount, hCount) -> {

        outFile.write(String.valueOf(marioStepCreator(space, sCount)));

        outFile.flush();

        outFile.write(String.valueOf(marioStepCreator(hash, hCount)));

        outFile.flush();

        outFile.write("\n");

        });

    } catch (FileNotFoundException e) {

        e.getCause();

    } catch (IOException e) {

        e.printStackTrace();

    }

}

private static void printToScreen(char space, char hash, int spaceCount, int hashCount) {

    loop(spaceCount, hashCount, (sCount, hCount) -> {

        System.out.print(marioStepCreator(space, sCount));

        System.out.print(marioStepCreator(hash, hashCount));

        System.out.println();

    });

}

private static void loop(int spaceCount, int hashCount, final BiConsumer<Integer, Integer> consumer) {

    for (int i = 0; i < 8; i++) {

        consumer.accept(spaceCount, hashCount);

        hashCount++;

        spaceCount--;

    }

}