关闭一个打印流

所以我基本上是创建一个包，我被告知我的包之一必须包含至少100000个元素。这不适合eclipse的控制台窗口。所以将信息写入文件似乎是一个更好的主意。我已经把我的主要方法和runBigBad方法放在这里。正如你所看到的，在runBigBag之后，我想要做更多的事情。它编译和运行良好。但是，它将runBigBag（）调用后的所有内容都打印到文本文件中。我只想在文本文件中使用runBigBag（）的内容，其余部分则打印到控制台窗口中。有人可以帮我吗？当我尝试使用finally子句并执行ps.close（）时，它想要我初始化ps，然后使该文件为空。所以我不知道该怎么办，除非有一个更简单的方法。关闭一个打印流

public class TestBag { 

public static <E> void main(String[] args) { 
    //Start time for WHOLE PROGRAM 
    final long start = System.currentTimeMillis(); 
    //Run small bag 
    runSmallBag(); 
    //RESET COUNTERS TO ALLOW BIG BAG TO KEEP TRACK OF COMPLEXITY 
    Bag.resetCounters(); 
    //Run big bag 
    runBigBag(); 
    //Display the operation counters for each method used in whole program 
    System.out.println("Number of times add() was used for whole program: " + Bag.addCountA + "\n"); 
    System.out.println("Number of times remRand() was used for whole program: " + Bag.ranRemCountA + "\n"); 
    System.out.println("Number of times rem() was used for whole program: " + Bag.remCountA + "\n"); 
    System.out.println("Number of times contains() was used whole program: " + Bag.containsCountA + "\n"); 
    System.out.println("number of times addAll() was used whole program: " + Bag.addAllCountA + "\n"); 
    System.out.println("Number of times union() was used whole program: " + Bag.unionCountA + "\n"); 
    System.out.println("Number of times equal() was used whole program: " + Bag.equalsCountA + "\n"); 
    //End timer for whole program 
    final long end = System.currentTimeMillis(); 
    //Display timer for whole program 
    System.out.println("The whole program took " + ((end - start)*.001) + " seconds to run"); 
} 
public static <E> void runBigBag(){ 

    //Start time for big bag operations 
    final long start2 = System.currentTimeMillis(); 

    boolean prog = true; 

    //Create file to write bag too 
    File file = new File("bag.txt"); 
    PrintStream ps; 
    try { 
     ps = new PrintStream(new FileOutputStream(file)); 
     System.setOut(ps); 
    } catch (FileNotFoundException f) { 
     f.printStackTrace(); 
    } finally 
    //irrelevant code here 


    //End timer for big bag 
    final long end2 = System.currentTimeMillis(); 

    //Display timer for big bag 
    System.out.println("This part of the program took " + ((end2 - start2)*.001) + " seconds to run"); 

}

}

来源

2016-12-06 Russell Culpepper

使用放样变化如此之所有后续的System.out调用发送到您的文件写入默认的输出流。如果您不希望发生这种情况，请不要使用默认输出流进行文件写入。

您问题的最快答案就在这里。 How do I create a file and write to it in Java?

来源

2016-12-06 03:20:12 Tosh

虽然托什的答案可能会为我工作好，我居然发现了如何做到这一点我希望的方式：

PrintStream ps; 
PrintStream stdout = System.out;

我创建了一个使用默认的系统输出和另一个为PrintStream该方法的最后，我把：

System.setOut(stdout);

我敢肯定，这大概会在我不打算为背景的东西，但给我的输出，我需要。感谢您的建议@Tosh。

来源

2016-12-06 03:46:53

关闭一个打印流

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