将这句List<Food> list = new ArrayList<Food>()
改成这个却没有问题..?
List list = new ArrayList ()
为什么会这样?
---------- Java Compiler ----------
t1.java:25: cannot find symbol
symbol : method binarySearch(java.util.List<Food>,Food)
location: class java.util.Collections
int result = Collections.binarySearch(list, f[0]);
^
Note: t1.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error
Output completed (0 sec consumed)
- Java code
import java.util.*;class t1{ public static void main(String[] args) { List<Food> list = new ArrayList<Food>(); Vector<String> list2 = new Vector<String>(); Food[] f = new Food[8]; String []name ={"Q", "F", "B", "K", "J", "A", "G", "H"}; for(int i=0; i<f.length; i++){ f[i] = new Food(name[i]); list.add(f[i]); list2.add(name[i]); } Collections.sort(list); int result = Collections.binarySearch(list, f[0]); System.out.println("Found:" + result); }}class Food implements Comparable{ String name; public Food(String name){ this.name = name; } public String getName(){ return name; } public int compareTo(Object o) { if(this.name.compareToIgnoreCase(((Food)o).getName()) > 0) return 1; else if(this.name.compareToIgnoreCase(((Food)o).getName()) < 0) return -1; else return 0; }}------解决方案--------------------
是用的jdk5.0或以上吗