[英]Why is my method only reading one line of text?
我有一种方法可以读取文本文件的一部分,该文件有4个部分:日期,名称,描述和金额,例如
4/5/2018, gel, hair product, 20.00
4/4/2018, wax, hair product, 20.00
等等...
我的问题是我的方法只会读取第一行,然后输出我的catch方法,说找不到该文件。
public static void showRecordedExpense(String filename)throws IOException {
String date = "";
String name = "";
String description = "";
double amount = 0.00;
try{
Scanner read = new Scanner(new File(filename));
while (read.hasNextLine()){
String oneLine = read.nextLine();
String[] parts = oneLine.split(",");
try {
date = parts[0];
name = parts[1];
description = parts[2];
amount = Double.parseDouble(parts[3]);
System.out.printf("%15s%15s%15s%20s%n", "---------------", "---------------",
"---------------", "---------------------");
System.out.printf("%15s%15s%15s%31s%n","Date", "Name", "Description","Amount");
System.out.printf("%15s%14s%33s%15s%n",date,name,description,amount);
System.out.printf("%15s%15s%15s%20s%n", "---------------", "---------------",
"---------------", "---------------------");
}catch (Exception e){
System.out.println("no");
} finally {
read.close();
}
}
}catch (Exception e){
System.out.println("The file could not be found");
}
}
编辑:取出最后的工作。
在这里阅读有关finally
工作原理的详细信息。 由于您finally
与try/catch
配对,因此您目前正在while
循环的第一次迭代结束时关闭Scanner。 自关闭文件以来, while
的下一次迭代无法再从文件中读取,这就是为什么它仅读取第一行的原因。 考虑在while
循环完成后取出finally并仅关闭扫描仪。
try{
Scanner read = new Scanner(new File(filename));
while (read.hasNextLine()){
String oneLine = read.nextLine();
String[] parts = oneLine.split(",");
try {
date = parts[0];
name = parts[1];
description = parts[2];
amount = Double.parseDouble(parts[3]);
System.out.printf("%15s%15s%15s%20s%n", "---------------", "---------------",
"---------------", "---------------------");
System.out.printf("%15s%15s%15s%31s%n","Date", "Name", "Description","Amount");
System.out.printf("%15s%14s%33s%15s%n",date,name,description,amount);
System.out.printf("%15s%15s%15s%20s%n", "---------------", "---------------",
"---------------", "---------------------");
}catch (Exception e){
System.out.println("no");
}
}
read.close();
}catch (Exception e){
System.out.println("The file could not be found");
}
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