试图解决 - 字符串索引超出范围答案

【问题标题】：Trying to solve - String index out of range试图解决 - 字符串索引超出范围
【发布时间】：2020-04-06 23:09:27
【问题描述】：

我收到此错误：

Carregando os mapas: Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String 
index out of range: 4800
        at java.lang.String.substring(Unknown Source)
        at estaticos.Criptografador.descompilarMapaData(Criptografador.java:147)
        at variables.Mapa.<init>(Mapa.java:1306)
        at estaticos.GestorSQL.CARREGAR_MAPAS(GestorSQL.java:696)
        at estaticos.MundoDofus.criarServer(MundoDofus.java:1398)
        at estaticos.VrauEMU.main(VrauEMU.java:130)

我正在尝试解决，但我不能。

我的代码：（原来模拟器是西班牙文，所以之前是celula = celda）

public static Map<Integer, Celula> descompilarMapaData(Mapa mapa, String dData) {
        Map<Integer, Celula> celulas = new TreeMap<Integer, Celula>();
        for (int f = 0; f < dData.length(); f += 10) {
            String CellData = dData.substring(f, f + 10);
            List<Byte> celulaInfo = new ArrayList<Byte>();
            for (int i = 0; i < CellData.length(); i++)
                celulaInfo.add((byte) getNumeroPorValorHash(CellData.charAt(i)));
            int caminhavel = (celulaInfo.get(2) & 56) >> 3;// 0 = nao, 1 = meio, 4 = sim
            boolean linhaDeVisao = (celulaInfo.get(0) & 1) != 0;
            int layerObject2 = ( (celulaInfo.get(0) & 2) << 12) + ( (celulaInfo.get(7) & 1) << 12) + (celulaInfo.get(8) << 6)
                    + celulaInfo.get(9);
            boolean layerObjeto2Interac = ( (celulaInfo.get(7) & 2) >> 1) != 0;
            int objeto = (layerObjeto2Interac ? layerObject2 : -1);

            celulas.put(f / 10, new Celula(mapa, f / 10, caminhavel != 0, linhaDeVisao, objeto));
        }
        return celulas;

【问题讨论】：

标签： java string exception range substring

【解决方案1】：

问题在于迭代边界：

 for (int f = 0; f < dData.length(); f += 10) {
            String CellData = dData.substring(f, f + 10);

除非dData.length() 恰好能被 10 整除，否则这将迭代超出范围。为了说明，下面的 sn-p 将尝试读取 0-10 和 10-20，即使虚构的数组边界仅为 0-15。

for (let i = 0; i < 25; i += 10)
  console.log(i, i + 10);

也许简单地将上限限制为substring.length() 就足够了：

 for (int f = 0; f < dData.length(); f += 10) {
            int upperBound = min(f + 10, dData.length());
            String CellData = dData.substring(f, upperBound));

【讨论】：

【解决方案2】：

public static Map<Integer, Celula> descompilarMapaData(Mapa mapa, String dData) {
        Map<Integer, Celula> celulas = new TreeMap<Integer, Celula>();
        //changes are here
          for (int f = 0; f <= dData.length() - 10; f += 10) {
            String CellData = dData.substring(f, f + 10);
            List<Byte> celulaInfo = new ArrayList<Byte>();
            for (int i = 0; i < CellData.length(); i++)
                celulaInfo.add((byte) getNumeroPorValorHash(CellData.charAt(i)));
            int caminhavel = (celulaInfo.get(2) & 56) >> 3;// 0 = nao, 1 = meio, 4 = sim
            boolean linhaDeVisao = (celulaInfo.get(0) & 1) != 0;
            int layerObject2 = ((celulaInfo.get(0) & 2) << 12) + ((celulaInfo.get(7) & 1) << 12) + (celulaInfo.get(8) << 6)
                    + celulaInfo.get(9);
            boolean layerObjeto2Interac = ((celulaInfo.get(7) & 2) >> 1) != 0;
            int objeto = (layerObjeto2Interac ? layerObject2 : -1);

            celulas.put(f / 10, new Celula(mapa, f / 10, caminhavel != 0, linhaDeVisao, objeto));
        }
        return celulas;
    }

试试这个，我认为它对你有用。

【讨论】：

【解决方案3】：

谢谢你的回答:)

我放代码：

 for (int f = 0; f < dData.length(); f += 10) {
            int upperBound = min(f + 10, dData.length());
            String CellData = dData.substring(f, upperBound));

我现在得到了这个：

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 2, Size: 0
        at java.util.ArrayList.rangeCheck(Unknown Source)
        at java.util.ArrayList.get(Unknown Source)
        at estaticos.Criptografador.descompilarMapaData(Criptografador.java:152)
        at variables.Mapa.<init>(Mapa.java:1306)
        at estaticos.GestorSQL.CARREGAR_MAPAS(GestorSQL.java:696)
        at estaticos.MundoDofus.criarServer(MundoDofus.java:1398)
        at estaticos.VrauEMU.main(VrauEMU.java:130)

我觉得差不多了

【讨论】：