Java - StringIndexOutOfBoundsException

Question

首先,这是我的代码中有问题的部分; 这些都是非常基础的课程

public Passenger(String Name, String adress, String number, String password){
    count++;
    accId+=count;

    this.Name=Name;

    this.adress=adress;
    this.number=number;

    if(checkPw(password)==true){
        this.password=password;
    }

}

private boolean checkPw(String password){
    int length;
    length = password.length();

    if(length != 6){
        return false;
    }
    else if(password.charAt(0)==0){
        return false;
    }
    else {
        for (int i = 0; i < password.length();i++){
            if((password.charAt(i))==(password.charAt(i+1))){
                return false;
            }
        }
    }
    return true;        
}

识别TestClass:

public static void main(String[] args){
    Passenger gokhan=new Passenger("Gokhan","Istanbul","xxx","254651");

    System.out.println(gokhan.password);
}

所以,我认为问题出在Passenger类.这是我第一次在课堂上上课(我的意思是if(checkPw(密码)== true)部分).在测试类中,它看起来非常清晰,我从未想过会出现此错误.我该如何避免这条消息？

完整错误:

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 6
    at java.lang.String.charAt(String.java:658)
    at project1.Passenger.checkPw(Passenger.java:45)
    at project1.Passenger.<init>(Passenger.java:27)
    at project1.testClass.main(testClass.java:11)

Java结果:1

Answer 1

问题出在这里:

for (int i = 0; i < password.length();i++){
    if((password.charAt(i))==(password.charAt(i+1))){
        return false;
    }
 }

当您处于最后一次迭代时,您正试图访问char位于不存在string的位置i+1.

    text
       ^
       |
when i = 3 charAt(i) will return t and charAt(i+1) will throw the exception