Java Can';t正确存储sqlite
我想设置if语句来控制sqlite中的数据存储。但是,如果if语句不能阻止不正确的数据,则数据将全部或全部存储。请给我一些提示。谢谢Java Can';t正确存储sqlite,java,android,sqlite,Java,Android,Sqlite,我想设置if语句来控制sqlite中的数据存储。但是,如果if语句不能阻止不正确的数据,则数据将全部或全部存储。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 != " " ){ d
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"));
}
}
Java中的字符串与方法“equals”比较,而不是与运算符比较 也就是说,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"));
}
谢谢它起作用了。但是,我想问一下string.compareTo()和!string.equal()?因为我在前面的编码中使用了比较器?非常感谢。compareTo正在比较两个对象,并返回结果(0=对象相等,小于0=第一个对象比第二个对象小(按词典编纂),大于0=第一个对象比第二个对象大(按词典编纂)。如果对象相等,则返回布尔值(在此上下文中为字符串对象)