我正在尝试对两个LinkedHashMap的值进行排序.我可以编译它并运行代码,但是它告诉我在编译期间使用-Xlint选项,因为它是不安全的代码.它与类型转换有关,但是我对如何做到这一点感到非常困惑.我把这节课放在班上：

static class MyComparator implements Comparator {

public int compare(Object obj1, Object obj2){

int result=0;

Map.Entry e1 = (Map.Entry)obj1 ;

Map.Entry e2 = (Map.Entry)obj2 ;//Sort based on values.

Integer value1 = (Integer)e1.getValue();

Integer value2 = (Integer)e2.getValue();

if(value1.compareTo(value2)==0){

String word1=(String)e1.getKey();

String word2=(String)e2.getKey();

//Sort String in an alphabetical order

result=word1.compareToIgnoreCase(word2);

} else {

//Sort values in a descending order

result=value2.compareTo( value1 );

}

return result;

}

}

我尝试使用以下功能之一调用它：

ArrayList myArrayList=new ArrayList(this.map_freq_by_date.entrySet());

Collections.sort(myArrayList, new MyComparator());

Iterator itr=myArrayList.iterator();

注意：this.map_freq_by_date的定义如下：

Map map_freq_by_date = new LinkedHashMap();

我用-Xlint选项得到的错误：

unchecked call to ArrayList(java.util.Collection extends E>) as a member of the raw type java.util.ArrayList

ArrayList myArrayList=new ArrayList(this.map_freq_by_date.entrySet());

unchecked conversion

found LogGrep.MyComparator

required: java.util.Comparator(? super T>

Collections.sort(myArrayList, new MyComparator());

unchecked method invocation: sort(java.util.List,java.util.Comparator super T> in java.util.Collections is applied to (java.util.ArrayList,LogGrep.MyComparator)

Collections.sort(myArrayList, new MyComparator());

帮助如何解决这些问题将不胜感激.我上网查看并尝试了所显示的各种方法,但似乎无法正确完成.

注意：如果我将ArrayList< Object> myArrayList = new ArrayList< Object> …错误更改为：

unchecked method invocation sort(java.util.List,java.util.Comparator<> super T?) in java.util.Collections is applied ot (java.util.ArraList,LogGrep.MyComparator)

Collections.sort(myArrayList, new MyComparator());