Question

我在使用stackoverflow atm进行编程时非常糟糕，对我很轻松，我正在努力学习。从阅读此代码，用于避免NumberFormatExpection的正确语法是什么？ `

package in.parapengu.spork.rotation;

import com.google.common.base.Charsets;
import in.parapengu.commons.utils.file.TextFile;
import in.parapengu.spork.Spork;
import in.parapengu.spork.exception.rotation.RotationLoadException;
import in.parapengu.spork.map.MapLoader;
import in.parapengu.spork.util.Log;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;

public class Rotation {

    private static int MAX_SIZE = 30;
    private static boolean OVERFLOW = true;

    private File file;
    private int index;
    private List<MapLoader> loaders;
    private List<RotationSlot> slots;

    public Rotation(File file, List<MapLoader> loaders, int index) {
        this.file = file;
        this.index = index;
        this.loaders = loaders;
        this.slots = new ArrayList<>();

        if(loaders.size() > MAX_SIZE && OVERFLOW) {
            for(MapLoader loader : loaders) {
                            try {


                slots.add(new RotationSlot(loader));
                            } catch(Exception ex) {
                    ex.printStackTrace();
                }    
            }
        } else {
                    try {
            while(slots.size() < MAX_SIZE) {
                for(int i = 0; i < loaders.size() && slots.size() < MAX_SIZE; i++) {
                    slots.add(new RotationSlot(loaders.get(i)));
                }

                if(slots.size() == 0) {
                    Log.warning("No slots were loaded");
                    break;
                } 
            }
        } catch(Exception ex) {
                    ex.printStackTrace();
                }    
                }
    }

    public Rotation(File file, List<MapLoader> loaders) {
        this(file, loaders, 0);
    }

    public File getFile() {
        return file;
    }

    public int getIndex() {
        return index;
    }

    public List<RotationSlot> getSlots() {
        return slots;
    }

    public boolean save() {
        TextFile file;
        try {
            file = new TextFile(this.file);
        } catch(IOException ex) {
                        ex.printStackTrace();
            Log.exception(ex);
            return false;
        }

        file.line(index + "");
        for(MapLoader loader : loaders) {
            file.line(loader.getName());
        }

        file.save();
        return true;
    }

    public static Rotation parse(File file) throws RotationLoadException {
        if(!file.exists()) {
            throw new RotationLoadException(file, file.getName() + " does not exist");
        }

        if(file.isDirectory()) {
            throw new RotationLoadException(file, file.getName() + " was a directory");
        }

        List<String> lines;
        try {
            lines = Files.readAllLines(file.toPath(), Charsets.UTF_8);
        } catch(IOException ex) {
                        ex.printStackTrace();
            throw new RotationLoadException(file, ex);
        } 

        String first = lines.get(0);
        int index;
        try {
            index = Integer.parseInt(first);
        } catch(NumberFormatException ex) {
                        ex.printStackTrace();
            throw new RotationLoadException(file, "The rotation index was not a valid number");

        } 

        lines.remove(0);
        List<MapLoader> maps = new ArrayList<>();
        for(String line : lines) {
            MapLoader loader = Spork.getMaps().getMap(line);
            if(loader == null) {
                throw new RotationLoadException(file, "Could not find a map matching \"" + line + "\"");
            }

            maps.add(loader);
        }

        return new Rotation(file, maps, index);
    }

}

`

这是我在控制台中遇到的错误： `

[06:27:59 WARN]: java.lang.NumberFormatException: For input string: "1Test"
[06:27:59 WARN]:        at java.lang.NumberFormatException.forInputString(Unknow
n Source)
[06:27:59 WARN]:        at java.lang.Integer.parseInt(Unknown Source)
[06:27:59 WARN]:        at java.lang.Integer.parseInt(Unknown Source)
[06:27:59 WARN]:        at in.parapengu.spork.rotation.Rotation.parse(Rotation.j
ava:115)

`

Answer 1

NumberFormatException的原因是因为，您正在尝试转换alpha数字字符串＆＃34; 1Test＆＃34;数字。

尝试删除字符串中的所有字符，如：

String name ="1Test";//why are you reading string?
Integer number = Integer.parseInt(name.replaceAll("[^0-9]", ""));
System.out.println(number);

您正在正确捕获异常并重新抛出RotationLoadException。

用于此NumberFormatException的正确语法是什么？

1 个答案: