关于java：如何压缩大型switch语句

How to condense large switch statements

我有一个大开关，如下所示：

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public int procList(int prov, ArrayList<TXValue> txValueList, Context context)
{
switch(prov)
{
case Foo.PROV_ONE:
return proc_one(txValueList, context);

case Foo.PROV_NOE:
return proc_noe(txValueList, context);

case Foo.PROV_BAR:
return proc_bar(txValueList, context);

case Foo.PROV_CABAR:
return proc_cabar(txValueList, context);

case Foo.PROV_FAR:
return proc_far(txValueList, context);

case Foo.PROV_TAR:
return proc_tar(txValueList, context);

case Foo.PROV_LBI:
return 408;

default:
return -1;
}
}

在C++中，我可以使用EDCOX1×0，并以如下方式使用它：

1	map[prov](txValueList, context);

Java中没有指向函数的指针。但是，它使用抽象类，就像它在答案中一样。那么，有没有一种最好的方法来消除Java中的EDCOX1 1条子句呢？

相关讨论

您要查找的是枚举。

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public enum Prov {
PROV_ONE(Foo.PROV_ONE) {
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return proc_one(txValueList, context);
}
},
PROV_NOE(Foo.PROV_NOE) {
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return proc_noe(txValueList, context);
}
},
PROV_BAR(Foo.PROV_BAR) {
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return proc_bar(txValueList, context);
}
},
PROV_CABAR(Foo.PROV_CABAR) {
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return proc_cabar(txValueList, context);
}
},
PROV_FAR(Foo.PROV_FAR) {
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return proc_far(txValueList, context);
}
},
PROV_TAR(Foo.PROV_TAR) {
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return proc_tar(txValueList, context);
}
},
PROV_LBI(Foo.PROV_LBI) {
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return 408;
}
},
UNKNOWN(Integer.MIN_VALUE) { // make sure this is not used in other IDs
//decide if you actually need this
@Override
public int provMethod(List<TXValue> txValueList, Context context) {
return -1;
}
};

private int id;

private Prov(int id) {
this.id = id;
}

public abstract int provMethod(List<TXValue> txValueList, Context context);

public static Prov getById(int id) {
for(Prov prov : Prov.values()) {
if(id == prov.id) {
return prov;
}
}
//return null;
//throw new IllegalArgumentException("Specified id was not found.");
return Prov.UNKNOWN;
}
}

然后你可以做

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public int procList(int prov, ArrayList<TXValue> txValueList, Context context)
{
return Prov.getById(prov).provMethod(txValueList, context);
}