Question

怎么获取数组里对象的某一项属性值

通过查询数据库返回一个ResultSet对象，为了不出异常我把结果放在一个ArrayList对象里面返回这个ArrayList，现在我要用到结果集里的一个数据的某一项值，该如何调用？代码如下：
public List userList(){
List reportList = new ArrayList();
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mvc", "root", "root");
String sql = "select * from reportForms ";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);

while(rs.next()){
UserVO vo = new UserVO();
vo.setId(rs.getString("id"));
vo.setTime(rs.getString("time"));
vo.setInfo(rs.getString("info"));
vo.setCount(rs.getString("count"));
vo.setName(rs.getString("name"));
reportList.add(vo);
}
} catch (Exception ex) {
ex.printStackTrace();
}
return reportList;
}
UserVO 代码：
public class UserVO {
private String id;
private String time;
private String info;
private String count;
private String name;
public String getCount() {
return count;
}
public void setCount(String count) {
this.count = count;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getTime() {
return time;
}
public void setTime(String time) {
this.time = time;
}

}
然后我调用上面那个userlist 方法，返回的是个List，我现在想使用VO 里的那个id，该怎么做？

Answer 1

userlist.indexOF(XX)就可以的里面的对象
然后在获取里面的属性
userlist.indexOF(XX).对象的public属性和方法；

Answer 2

Iterator<UserVO> userVOit = reportList.iterator();
UserVO userVO = null;
String str;
while(userVOit.hasNext()) {
userVO = userVOit.next();
//此处就可以得到userVO对象的任何属性值了,比如:
str = userVO.getName();
}

Answer 3

例如：let a=[{x:5}]
想要取出对象里的属性x的值 ：直接a[0].x
0是下标

Answer 4

((UserVO)(list.get(0))).getId();//list是userList的返回list

Answer 5

List list = userList();
for (int i = 0; i < reportList.size(); i++)
{
UserVO vo = (UserVO) reportList.get(i);
String id= vo.getId();
}