可以啊。
见下面:1.Me.javapublic class Me{ String me; public Me( String me ){ this.me = me; } public String getMe(){
return me;
}
}2. You.java
public class You {
public static void main(String[] args) {
ArrayList arrays = new ArrayList();
Me aa = new Me("java");
Me bb = new Me("oracle");
arrays.add(aa);
arrays.add(bb); for (int i = 0; i < arrays.size(); i++) {
System.out.println(((Me)arrays.get(i)).getMe());
}
}
}
见下面:1.Me.javapublic class Me{ String me; public Me( String me ){ this.me = me; } public String getMe(){
return me;
}
}2. You.java
public class You {
public static void main(String[] args) {
ArrayList arrays = new ArrayList();
Me aa = new Me("java");
Me bb = new Me("oracle");
arrays.add(aa);
arrays.add(bb); for (int i = 0; i < arrays.size(); i++) {
System.out.println(((Me)arrays.get(i)).getMe());
}
}
}
ArrayList array = new ArrayList( );Me aa = new Me("java");array.add(aa);Me ss = new Me("oracle");array.add(ss);是在类的构造方法里面写的,而你测试时没有new一个这个类.
1 Me.java
class Me{ String me; public Me( String me ){ this.me = me; } public String getMe(){
return me;
}
}2 You.java
import java.util.ArrayList;public class You {
public static void main(String[] args) {
ArrayList arrays = new ArrayList();
Me aa = new Me("java");
Me bb = new Me("oracle");
arrays.add(aa);
arrays.add(bb); for (int i = 0; i < arrays.size(); i++) {
System.out.println( ((Me)arrays.get(i)).getMe() );
}
}
}注意这两个文件要放在有关目录下,你是不是少了一句:“import java.util.ArrayList;”,加上就可以了
((Me)arrays.get(i)).getMe()我没把(Me)array.get(i)给夸起来,导致把arrays.get(i)).getMe()这个值转成Me类型再一个问题,,如果ArrayList为空怎么办呢?是自己的代码抛出这异常,并定义一变量为ArrayList的size()大小?刚把数据库里的资料给清除才发现这问题。
try {
......
arrays.get(i);
} catch(Exception e) {
System.err.println(e.getMessage());//处理异常
}
//do what you want to do!
}