Java在不同地方打印出抛出异常和不抛出异常

Question

我不知道如何制定标题，但我遇到了以下问题。我正在制作一个程序，从 CSV 文件中读出内容并将其输入。在没有问题的文件中，我可以正常得到结果。当我运行另一个抛出错误的文件时，我的程序仍然打印出我在 catch 中的内容，但不是按照我想要的顺序打印 - 我想将所有有错误的部分放在上面，而那些没有错误的部分放在上面打印件的底部。我怎样才能做到这一点？这是我目前拥有的代码

           String []arrayS = line.split(",");
           if(arrayS.length==7){
              String fName = "";
              String lName = "";
                             //String 
              int bDay;
              int bMonth;
              int bYear;
              int weight;
              double height;
              try{
                 //System.out.printf("%15s%15s%15s%15s \n", fnlName , birthDate, sWeight, sHeight);

                 fName = arrayS[0];//gets first line in csv- name
                 lName = arrayS[1];//gets second line in csv- last name
                 try{
                 bDay = Integer.parseInt(arrayS[2].trim());//gets third line in csv- birth day
                 }catch (NumberFormatException nfe){
                    System.err.println("Error found in" + arrayS[0] + ", " + arrayS[1] + ", " + arrayS[2]  + ", " + arrayS[3]  + ", " + arrayS[4]  + ", " + arrayS[5] + ", " + arrayS[6] +"\n Offending item is: Birth day");
                    continue;
                 }try{
                 bMonth = Integer.parseInt(arrayS[3].trim());//gets four line in csv- birth month
                 }catch (NumberFormatException nfe){
                    System.err.println("Error found in" + arrayS[0] + ", " + arrayS[1] + ", " + arrayS[2]  + ", " + arrayS[3]  + ", " + arrayS[4]  + ", " + arrayS[5] + ", " + arrayS[6] +"\n Offending item is: Birth month");
                    continue;
                 }try{
                 bYear = Integer.parseInt(arrayS[4].trim());//gets fifth line in csv- birth year
                 }catch (NumberFormatException nfe){
                    System.err.println("Error found in" + arrayS[0] + ", " + arrayS[1] + ", " + arrayS[2]  + ", " + arrayS[3]  + ", " + arrayS[4]  + ", " + arrayS[5] + ", " + arrayS[6] +"\n Offending item is: Birth year");
                    continue;
                 }try{
                 weight = Integer.parseInt( arrayS[5].trim());//gets sixth line in csv- weight
                 }catch (NumberFormatException nfe){
                    System.err.println("Error found in" +arrayS[0] + ", " + arrayS[1] + ", " + arrayS[2]  + ", " + arrayS[3]  + ", " + arrayS[4]  + ", " + arrayS[5] + ", " + arrayS[6] +"\n Offending item is: Weight");
                    continue;
                 }try{
                 height = Double.parseDouble(arrayS[6].trim());//gets seventh line in csv- height
                 }catch (NumberFormatException nfe){
                    System.err.println("Error found in" + arrayS[0] + ", " + arrayS[1] + ", " + arrayS[2]  + ", " + arrayS[3]  + ", " + arrayS[4]  + ", " + arrayS[5] + ", " + arrayS[6] +"\n Offending item is: Height");
                    continue;
                 }
                 System.out.printf("%15s%15s%02d/%02d/%4d %d %.1f\n" , fName , lName  , bDay , bMonth , bYear , weight , height);

              }catch(NumberFormatException nfe ){
                 System.out.println("Cannot read student:" +  fName);
                 continue;
              }}```

Answer 1

不要将输出直接写入 System.out和System.err但首先要收集它们。您可以使用不同的方法，例如使用 List<String>或使用 StringBuilder 。当您完全读取 CSV 文件后，您终于可以输出最后收集的结果，首先是错误，然后是无错误的条目。代码可以如下所示:

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

while (/*reading a line */) {
    /* [...] */

    try {
        /* [...] */
        output.add(String.format("...", a, b, c, d, ...);
    } catch (...) {
        errors.add(...);
    }
}

// now show the result, but show the errors first
if (!errors.isEmpty()) {
    System.err.println("There were errors:");
    for (String str: errors) {
        System.err.println(str);
    }
}
System.out.println("Your result");
for (String str: output) {
    System.out.println(str);
}