我正在为我的编程类开发一个项目，我遇到了BufferedReader的问题。这是代码。它运行正常，但它只读取我的csv文件中的每隔一行。我认为问题是我有两次inFile = input.readLine，但如果我删除其中一个，我就会遇到运行时错误。
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.*;
import java.io.BufferedReader;
public class CrimeData {
public static void main(String[] args) throws FileNotFoundException {
BufferedReader input = new BufferedReader(new FileReader("crime.csv"));
String inFile;
try {
inFile = input.readLine();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int n = 0;
int year[] = new int[50], population[] = new int[50], violentCrime[] = new int[50];
double violentCrimeRate[] = new double[50];
int murderAndNonnegligentManslaughter[] = new int[50];
double murderAndNonnegligentManslaughterRate[] = new double[50];
int rape[] = new int[50];
double rapeRate[] = new double[50];
int robbery[] = new int[50];
double robberyRate[] = new double[50];
int aggravatedAssault[] = new int[50];
double aggravatedAssaultRate[] = new double[50];
int propertyCrime[] = new int[50];
double propertyCrimeRate[] = new double[50];
int burglary[] = new int[50];
double burglaryRate[] = new double[50];
int larcenyTheft[] = new int[50];
double larcenyTheftRate[] = new double[50];
int motorVehicleTheft[] = new int[50];
double motorVehicleTheftRate[] = new double[50];
try {
while ((inFile = input.readLine()) != null) {
String words[] = input.readLine().split(",");
year[n] = Integer.parseInt(words[0]);
population[n] = Integer.parseInt(words[1]);
violentCrime[n] = Integer.parseInt(words[2]);
violentCrimeRate[n] = Double.parseDouble(words[3]);
murderAndNonnegligentManslaughter[n] = Integer.parseInt(words[4]);
murderAndNonnegligentManslaughterRate[n] = Double.parseDouble(words[5]);
rape[n] = Integer.parseInt(words[6]);
rapeRate[n] = Double.parseDouble(words[7]);
robbery[n] = Integer.parseInt(words[8]);
robberyRate[n] = Double.parseDouble(words[9]);
aggravatedAssault[n] = Integer.parseInt(words[10]);
aggravatedAssaultRate[n] = Double.parseDouble(words[11]);
propertyCrime[n] = Integer.parseInt(words[12]);
propertyCrimeRate[n] = Double.parseDouble(words[13]);
burglary[n] = Integer.parseInt(words[14]);
burglaryRate[n] = Double.parseDouble(words[15]);
larcenyTheft[n] = Integer.parseInt(words[16]);
larcenyTheftRate[n] = Double.parseDouble(words[17]);
motorVehicleTheft[n] = Integer.parseInt(words[18]);
motorVehicleTheftRate[n] = Double.parseDouble(words[19]);
n++;
}
} catch (NumberFormatException | IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Scanner scan = new Scanner(System.in);
while (true) {
System.out.println("********** Welcome to the US Crime Statistical Application **************************");
System.out.println("Enter the number of the question you want answered. ");
System.out.println("1. What were the percentages in population growth for each consecutive year from 1994 – 2013?");
System.out.println("2. What year was the Murder rate the highest?");
System.out.println("3. What year was the Murder rate the lowest?");
System.out.println("4. What year was the Robbery rate the highest?");
System.out.println("5. What year was the Robbery rate the lowest?");
System.out.println("6. What was the total percentage change in Motor Vehicle Theft between 1998 and 2012?");
System.out.println("7. What was [enter your first unique statistic here]?");
System.out.println("8. What was [enter your second unique statistic here]?");
System.out.println("9. Quit the program");
System.out.println("Enter your selection: ");
int choice = scan.nextInt();
double low, high, percent;
int y;
switch (choice) {
case 1:
for (int i = 1; i < n; i++) {
percent = ((population[i] - population[i - 1]) / population[i - 1]) * 100;
System.out.println(
"Percentage of population growth during " + year[i - 1] + "-" + year[i] + " :" + percent);
}
break;
case 2:
high = murderAndNonnegligentManslaughter[0];
y = year[0];
for (int i = 1; i < n; i++) {
if (murderAndNonnegligentManslaughter[i] > high) {
high = murderAndNonnegligentManslaughter[i];
y = year[i];
}
}
System.out.println("The year has the highest Murder rate : " + y);
break;
case 3:
low = murderAndNonnegligentManslaughter[0];
y = year[0];
for (int i = 1; i < n; i++) {
if (murderAndNonnegligentManslaughter[i] < low) {
low = murderAndNonnegligentManslaughter[i];
y = year[i];
}
}
System.out.println("The year has the lowest Murder rate : " + y);
break;
case 4:
high = robberyRate[0];
y = year[0];
for (int i = 1; i < n; i++) {
if (robberyRate[i] > high) {
high = robberyRate[i];
y = year[i];
}
}
System.out.println("The year has the highest Robbery rate : " + y);
break;
case 5:
low = robberyRate[0];
y = year[0];
for (int i = 1; i < n; i++) {
if (robberyRate[i] < low) {
low = robberyRate[i];
y = year[i];
}
}
System.out.println("The year has the lowest Robbery rate : " + y);
break;
case 6:
double rateChange = 0;
rateChange = (motorVehicleTheft[19] - motorVehicleTheft[5]);
System.out.println(motorVehicleTheft);
case 7:
break;
case 8:
break;
case 9:
System.out.println("Thank you for using the Crime Database");
System.exit(0);
}
}
}
}
答案 0 :(得分：0)
你的猜测绝对正确。
这会跳过，因为while循环中的第一个条件是读取一行
while((infile = input.readLine()) != null){
但是您没有对读入行做任何事情。
然后下次你打电话
input.readLine();
您阅读了下一行，但实际上您对该行做了一些事情。
如需进一步参考，请尝试查看此主题：