java - 无法正确存储 sqlite

Question

我想设置if语句来控制sqlite中的数据存储。但是，数据将被全部存储或全部不存储，因此if语句不能阻止不正确的数据。请给我一些提示。谢谢。

public void luggageCheck (String ncode, String luggage1, String luggage2, String luggage3){

    DatabaseHandler db = new DatabaseHandler(this);

    if (luggage1 !=  " " ){
        db.addContact(new Luggage(ncode, luggage1, "luggage")); 
    }
    if (luggage2 !=  " "){
        db.addContact(new Luggage(ncode, luggage2, "luggage"));
    }
    if (luggage3 !=  " "){
        db.addContact(new Luggage(ncode, luggage3, "luggage"));
    }

}

Answer 1

Java中的字符串是通过“equals”方法进行比较的，而不是通过运算符进行比较的

这意味着您的代码应该是:

if (!luggage1.equals(" ")){
    db.addContact(new Luggage(ncode, luggage1, "luggage")); 
}
if (!luggage2.equals(" ")){
    db.addContact(new Luggage(ncode, luggage2, "luggage"));
}
if (!luggage3.equals(" ")){
    db.addContact(new Luggage(ncode, luggage3, "luggage"));
}