if else 语句中的多个布尔值在 Java 中始终为 false

Question

我坚持使用这个方法，因为 if else 条件说

Condition usersInSales && usersInPayments is always false
Condition usersInSales && usersInLoans is always false
Condition usersInPayments && usersInLoans is always false

我尝试了不同的条件组合并添加了假值来尝试解决它，但没有帮助。请问我能帮忙吗？提前致谢

private List<UserResource> usersFilteredByDepartment(List<UserResource> users, boolean usersInSales, boolean usersInPayments, boolean usersInLoans) {

        if (usersInSales) {
            return getUsersInSales(users);
        } else if (usersInPayments) {
            return getUsersInPayments(users);
        } else if (usersInLoans) {
            return getUsersInLoans(users);
        } else if (usersInSales && usersInPayments) {
            return Stream.concat(getUsersInSales(users).stream(), getUsersInPayments(users).stream()).distinct().collect(Collectors.toList());
        } else if (usersInSales && usersInLoans) {
            return Stream.concat(getUsersInSales(users).stream(), getUsersInLoans(users).stream()).distinct().collect(Collectors.toList());
        } else if (usersInPayments && usersInLoans) {
            return Stream.concat(getUsersInPayments(users).stream(), getUsersInLoans(users).stream()).distinct().collect(Collectors.toList());
        } else return users;
    }

Answer 1

考虑一下您的逻辑：您首先检查 usersInSales，然后检查 return 是否为真。然后检查 usersInPayments 和 return 是否为真。因此，当您随后检查 usersInSales && usersInPayments 时，两者都将为假，因为您已经处理了其中任何一个为真的情况。

您需要更改您的逻辑，以便处理附加条件而不是专门处理条件。

Answer 2

if (usersInSales) {
        return getUsersInSales(users);
    } else if (usersInPayments) {    ---> You get here when userInSales = false
        return getUsersInPayments(users);
    } else if (usersInLoans) {  --> You get here when usersInSales = false && usersInPayments = false
        return getUsersInLoans(users);
    }  else if () {  --> You get here when usersInSales = false && usersInPayments = false && usersInLoans = false. No use in comparing what you compare here. It will be always false as it reports to
     }

希望你现在能找到出路

您可以尝试先检查最具体的约束，然后再检查更一般的约束。

if (usersInSales && usersInPayments) {
        return Stream.concat(getUsersInSales(users).stream(), getUsersInPayments(users).stream()).distinct().collect(Collectors.toList());
    } else if (usersInSales && usersInLoans) {
        return Stream.concat(getUsersInSales(users).stream(), getUsersInLoans(users).stream()).distinct().collect(Collectors.toList());
    } else if (usersInPayments && usersInLoans) {
        return Stream.concat(getUsersInPayments(users).stream(), getUsersInLoans(users).stream()).distinct().collect(Collectors.toList());
    } else if (usersInSales) {
        return getUsersInSales(users);
    } else if (usersInPayments) {
        return getUsersInPayments(users);
    } else if (usersInLoans) {
        return getUsersInLoans(users);
    } else return users;

检查您的工作流程，但是在我看来，如果没有所有这些 if, else 检查，您的方法会更有意义。 这个就够了

 private List<UserResource> usersFilteredByDepartment(List<UserResource> users, boolean usersInSales, boolean usersInPayments, boolean usersInLoans) {
    
     return Stream.concat(
usersInPayments? getUsersInPayments(users).stream(): Stream.empty(),
usersInLoans? getUsersInLoans(users).stream(): Stream.empty(), 
usersInSales? getUsersInSales(users).stream(): Stream.empty()
).distinct().collect(Collectors.toList());
    
}

Answer 3

你的最后 3 个条件永远不会运行。因为您的前 3 个条件之一已经为真。要解决此问题，您需要颠倒条件的顺序，试试这个：

if (usersInSales && usersInPayments) {
    } else if (usersInSales && usersInLoans) {
    } else if (usersInPayments && usersInLoans) {
    } else if (usersInSales ) {
    } else if ( usersInLoans) {
    } else if (usersInLoans) {
    } else return users;

Answer 4

您有两个解。

重新排序您的条件，如其他人所示。在您的代码中，当您点击 && 语句时，您已经处理了一半为真的情况。 &&（两个子句）比单个子句更具限制性。

或者，将双子句放在前面的 ifs 中。

 if (usersInSales) {
     return getUsersInSales(users);
 } else if (usersInPayments) {
     return getUsersInPayments(users);
 } else if (usersInLoans) {
     return getUsersInLoans(users);
 } else if (usersInSales && usersInPayments) {
     return Stream.concat(getUsersInSales(users).stream(), getUsersInPayments(users).stream()).distinct().collect(Collectors.toList());
 } else if (usersInSales && usersInLoans) {...

变成

    if (usersInSales) {
        if (usersInPayments) { // Nested if is like && operator.
            return Stream.concat(getUsersInSales(users).stream(), getUsersInPayments(users).stream()).distinct().collect(Collectors.toList());
        } else {
            return getUsersInSales(users);
        }
    } else if (usersInPayments) { ...

这样效率更高一些，我认为通常更可取。

if else 语句中的多个布尔值在 Java 中始终为 false

Multiple boolean values in if else statement is always false in Java

java

spring

boolean-logic