InputMismatchException时
-
22-07-2019 - |
题
我想从.txt文件读到MMORPG字符的数据,然后在经验(最小经验)滤波器。但我发现了此异常,这是我知道的意思,但我真的不明白我在做什么错了。
我在java的不好,实际上,我是初学者。有人可以解释这样对我?也许我在做一件很愚蠢的。
这是我的代码:
<强> Karakter(字符):强>
import java.util.Scanner;
public class Karakter {
private String name;
private int experience;
private int maxHealthPoints;
private int healthPoints;
private int maxGreed;
private int greed;
public Karakter(String nm, int exp, int mHP, int hp, int mG, int g)
{
name = nm;
experience = exp;
maxHealthPoints = mHP;
healthPoints = hp;
maxGreed = mG;
greed = g;
}
public String toString()
{
String s = "";
s += getName();
s += getExperience();
s += getMaxHealthPoints();
s += getHealthPoints();
s += getMaxGreed();
s += getGreed();
return s;
}
public static Karakter read(Scanner sc)
{
String name = sc.next();
int experience = sc.nextInt();
int maxHealthPoints = sc.nextInt();
int healthPoints = sc.nextInt();
int maxGreed = sc.nextInt();
int greed = sc.nextInt();
return new Karakter(name, experience, maxHealthPoints, healthPoints, maxGreed, greed);
}
public boolean hasExperience(int min)
{
return experience >= min;
}
// returns true if Krakters have the same name
public boolean equals(Object other)
{
if(!(other instanceof Karakter))
{
return false;
}
else
{
Karakter that = (Karakter) other;
return that.name == this.name;
}
}
public String getName()
{
return name;
}
public int getExperience()
{
return experience;
}
public int getMaxHealthPoints()
{
return maxHealthPoints;
}
public int getHealthPoints()
{
return healthPoints;
}
public int getMaxGreed()
{
return maxGreed;
}
public int getGreed()
{
return greed;
}
}
<强> Karakters(字符):强>
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;
public class Karakters {
private ArrayList<Karakter> kars = new ArrayList<Karakter>();
public void voegToe(Karakter kar)
{
if(!kars.contains(kar))
{
kars.add(kar);
}
}
// returns an arraylist of characters with exp >= minexp
public ArrayList<Karakter> karaktersVanaf(int minExperience)
{
Karakter kar = null;
for(int i = 0; i < kars.size(); i++)
{
if(kar.hasExperience(minExperience))
kars.add(kar);
}
return kars;
}
public static Karakters read(String infile)
{
Karakters k = new Karakters();
try
{
FileReader fr = new FileReader(infile);
Scanner sc = new Scanner(fr);
int aantal = sc.nextInt();
for(int i = 0; i < aantal ; i++)
{
Karakter kar = Karakter.read(sc);
k.kars.add(kar);
}
fr.close();
}
catch(IOException iox)
{
System.out.println(iox);
return null;
}
return k;
}
}
<强> KarakterZoeker(主法):强>
import java.util.ArrayList;
import java.util.Scanner;
public class KarakterZoeker {
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
Karakters kars = Karakters.read("infile.txt");
System.out.println("Welke experience wilt u minimaal?");
int minExp = sc.nextInt();
ArrayList<Karakter> s = kars.karaktersVanaf(minExp);
System.out.println(s.toString());
}
}
并是这种错误:强>
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Unknown Source)
at java.util.Scanner.next(Unknown Source)
at java.util.Scanner.nextInt(Unknown Source)
at java.util.Scanner.nextInt(Unknown Source)
at Karakter.read(Karakter.java:38)
at Karakters.read(Karakters.java:41)
at KarakterZoeker.main(KarakterZoeker.java:14)
<强>这些行:强>
Karakter kar = Karakter.read(sc); (in Karakters)
int experience = sc.nextInt(); (in Karakter)
Karakters kars = Karakters.read("infile.txt"); (in KarakterZoeker)
<强>这是txt文件:强>
2
name = Dursley
experience = 15
maxHealthPoints = 20
healthPoints = 10
maxGreed = 3
greed = 1
name = Aragorn
experience = 45
maxHealthPoints = 40
healthPoints = 30
maxGreed = 20
greed = 10
解决方案
的问题是,在这条线:
int experience = sc.nextInt();
您正在尝试读取“诠释”,但什么扫描器读取是一个字符串"experience"
这是此行中的.txt文件:
experience = 15
因此,你必须读两个字符串(1 ST 是 “经验” 和2 第二是 “=”),然后,你将能够读取的int( 15)等。
第一个没有失败,因为name
被分配一个字符串,但如果你登录你所读的,你有“名”,而不是真实姓名。
另一种方法是让ResourceBundle
类做供您阅读。甚至Properties
类。
使用资源包,你会做这样的事情:
ResourceBundle bundle = ResourceBundle.getBundle("Karakters");
String exp = bundle.getString("experience");
int experience = Integer.parseInt( exp );
和你将不得不名称为:Karakters.properties
修改强>
我已经加入上我将如何做到这一点使用ResouceBundle
样品
其他提示
InputMismatchException
是< EM>由Scanner抛出,指示检索与期望类型不匹配图案中的令牌或令牌超出范围的预期的类型。
所以,我的猜测是,你在呼唤nextInt
时,下一个标记是不实际的Integer
。
修改强>
读取文件时,你必须要小心,因为你有算令牌标签。举例来说,当你有:
maxHealthPoints = 20 ,
您有三个令牌: “maxHealthPoints”, “=”,和 “20”。问题是,您忽略的两个标签(前“=”)和等号。我的建议?按行读取文件行,然后使用Scanner
来分析每一行。另外,去掉标签,然后从文件上了等号,只留下要提取的值。
调用next()
两次固定的问题。从那以后,我在我的Karakters NullPointerException
得到了karaktersVanaf(minExp)
。为了解决这个问题,我添加这些行到我的代码:
public ArrayList<Karakter> karaktersVanaf(int minExperience) throws FileNotFoundException
{
Scanner sc = new Scanner(new FileReader("infile.txt")); // --------line 1
Karakter kar = Karakter.read(sc); // ------------ line 2
for(int i = 0; i < kars.size(); i++)
{
if(kar.hasExperience(minExperience))
kars.add(kar);
}
return kars;
}
但现在我再次看到InputMissMatschException
!我不知道我做错了!我可能会做一些完全错误的,所以要准备笑。
这是个办法,我没有经验的15分呢,这就是为什么我不能为你投票刚才。我只要我能做到这样做。
每个读者做了nextInt()或nextString()时,它不读取下一行,它读出由空白(空格或换行)分离出的下一个字符。解决您的问题,最简单的方法是删除“NAME =”,“经验=”,而只是把每行的唯一数据。
所以,你的文件看起来像:
2
Dursley
15
20
10
3
1
Aragorn
45
40
30
20
10
然后你的代码将工作是。
我已编码的方式使用的ResourceBundle阅读。
我离开这里,我希望你觉得它有用:
import java.util.*;
public class Ktr {
public static void main( String [] args ) {
ResourceBundle b = ResourceBundle.getBundle("k");
String names = b.getString("names");
List<K> l = new ArrayList<K>();
for( String name : names.split(",")){
l.add( K.read( name, b ));
}
System.out.println( l );
}
}
class K {
private String name;
private int maxHealthPoints;
private int maxGreed;
// etc..
public static K read( String name, ResourceBundle b ) {
K k = new K();
k.name = name;
k.maxHealthPoints =
Integer.parseInt(b.getString( name + ".maxHealthPoints") );
k.maxGreed =
Integer.parseInt(b.getString( name + ".maxGreed") );
// you get the idea
return k;
}
public String toString() {
return String.format("%s{maxHealthPoints=%d, maxGreed=%d}",
name, maxHealthPoints, maxGreed);
}
}
k.properties
names=Dursley,Aragorn
Dursley.maxHealthPoints=20
Dursley.maxGreed=3
Aragorn.maxHealthPoints=40
Aragorn.maxGreed=20
输出:
java Ktr
[Dursley{maxHealthPoints=20, maxGreed=3}, Aragorn{maxHealthPoints=40, maxGreed=20}]