我正在debian 5上使用Java
java版本为"1.6.0_20"
Java(TM) SE Runtime Environment(构建1.6.0_20-b02)
Java HotSpot(TM) Client VM(构建16.3-b01,混合模式,共享)
以下两种情况有何不同?
情况1:
import java.util.*;
情况2:
import java.util.*;
import java.util.Arrays;
import java.util.List;
为什么第一个情况不能覆盖第二个情况?
只有在显式导入Arrays和List时,代码才会编译。
代码:
import java.util.*;
import java.util.Arrays;
import java.util.List;
public class Test {
public static void main (String[] args) {
List<Integer> i = new ArrayList(Arrays.asList(1,2,3,4,5,6,7,8,9,10));
List<Integer> j = new ArrayList();
ListIterator<Integer> n = i.listIterator(i.size());
while(n.hasPrevious()) {
j.add(n.previous());
}
println(j);
}
static void println(Object o) {
System.out.println(o);
}
static void print(Object o) {
System.out.print(o);
}
}
当我注释掉第二个和第三个导入语句时,我得到的错误是:
nattyp@debian:~/dev/java$ javac Test.java
Test.java:7: cannot find symbol
symbol : method asList(int,int,int,int,int,int,int,int,int,int)
location: class Arrays
List<Integer> i = new ArrayList(Arrays.asList(1,2,3,4,5,6,7,8,9,10));
^
Note: Test.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error
nattyp@debian:~/dev/java$