java - 一会儿如何在 switch 中使用 try catch

Question

一旦我运行代码读取数据，程序执行就不会循环回来。

我尝试将 try catch 语句与 finally 语句一起放置的位置转移，并且所有中断方式都会继续。

    long code;
    char choice;


    Cars CarSales = new Cars(); //It creates a Java object and allocates memory for it on the heap.
    Scanner sc = new Scanner(System.in);

    System.out.println("   -----CARS SALES YARD------"); //The println is a method of java.io.PrintStream.
    do {
        System.out.println("1. Add item");
        choice = sc.nextLine().charAt(0);
        switch (choice) {     //switch statement allows a variable to be tested for equality against a list of values. 
        case '6':
            try{
            CarSales.ReadData();
            continue;
            }
            catch(IOException e){
                     System.out.println("Error reading file '" );
                     continue;
            }
        default:
            System.out.println("Invalid Selection\n");
        }
    } while (choice != '6'); //while loop statement repeatedly executes a statement as long as a given condition is true
    sc.close();

public void ReadData() throws IOException{//This Method is in the Cars class
String fileName = "input.txt";
String line = null;
FileReader fileReader = new FileReader(fileName);
BufferedReader bufferedReader = new BufferedReader(fileReader);
while((line = bufferedReader.readLine()) != null) {
            System.out.println(line);
    }   
bufferedReader.close();   
System.out.println("TRY");

尽管程序执行只是停止循环，但没有错误消息。

标签： java

Answer 1

通过将continue;移到之后catch。喜欢，

do {
    System.out.println("1. Add item"); //<-- where are 2-6?
    choice = sc.nextLine().charAt(0);
    switch (choice) {
    case '6': // <-- don't forget case '1' - '5'
        try {
            CarSales.ReadData();
        } catch (IOException e) {
            System.out.println("Error reading file '");
        }
        continue; // <-- here, or a break;
    default:
        System.out.println("Invalid Selection\n");
    }
} while (choice != '6');