在编写一些Java代码时，我遇到了一个我不认识的异常：java.lang.VerifyError。通过一些谷歌搜索，我发现这通常是jvm/javac的错误，我很好奇我的情况是否也是如此。
我怀疑的行是：
private Pair<Integer/*used size*/,Pair<K,V[]>[]>[] map=(Pair<Integer,Pair<K,V[]>[]>[])Array.newInstance(Pair.class,63);//good start number
并且
map[b]=new Pair<Integer,Pair<K,V[]>[]>(7,(Pair<K,V[]>[])Array.newInstance(Pair.class,7));
但我并不确定。
这是编译器错误还是我的代码有问题。
这些行是为了解决我在某个地方发现的泛型数组创建失败的问题而采取的变通方法。
附上代码。
package osm2spacebook;
import java.util.Iterator;
import java.lang.reflect.Array;
import java.util.NoSuchElementException;
public class MultiMap<K,V> implements Iterable<K>{
private int num_keys;
@SuppressWarnings("unchecked")
private Pair<Integer/*used size*/,Pair<K,V[]>[]>[] map=(Pair<Integer,Pair<K,V[]>[]>[])Array.newInstance(Pair.class,63);//good start number
@SuppressWarnings("unchecked")
private int bucket(K key){//position in bucket
int h=key.hashCode();
int b=h%map.length;
if(map[b]==null)
map[b]=new Pair<Integer,Pair<K,V[]>[]>(7,(Pair<K,V[]>[])Array.newInstance(Pair.class,7));
return b;
}
private int position(K key){//position within bucket
int b=bucket(key);//IMPORTANT this must use the buket function to obtain this otherwise it is a race
for(int i=0;i<map[b].v1;i++)
if(map[b].v2[i].v1==key)
return i;
if(map[b].v1==map[b].v2.length)
map[b].v2=java.util.Arrays.copyOf(map[b].v2,map[b].v1*2);
return map[b].v1++;
}
public V put(K key,V value){
Pair<K,V[]> m=map[bucket(key)].v2[position(key)];
for(int i=0;i<m.v2.length;i++)
if(m.v2[i]==value)
return value;
m.v2=java.util.Arrays.copyOf(m.v2,m.v2.length+1);
return m.v2[m.v2.length-1]=value;
}
public V[] get(K key){
V[] v=map[bucket(key)].v2[position(key)].v2;
return java.util.Arrays.copyOf(v,v.length);
}
public V[] remove(K key){
throw new UnsupportedOperationException("Not implemented"); //TODO
}
public V remove(K key,V value){
throw new UnsupportedOperationException("Not implemented"); //TODO
}
public boolean contains(K key){
return position(key)<map[bucket(key)].v1;
}
public int numKeys(){
return num_keys;
}
public Iterator<K> iterator(){
return new Iterator<K>(){
int bucket=0;
int position=0;
public boolean hasNext(){
while(bucket<map.length){
if(map[bucket]!=null)
if(position<map[bucket].v1)
return true;
else
position=0;
bucket++;
}
return false;
}
public K next(){
if(hasNext())//positions cursor on next element if any
return map[bucket].v2[position++].v1;//updates position after read
else
throw new NoSuchElementException();
}
public void remove(){
throw new UnsupportedOperationException("Remove not supported in multimap iterator du to ambiguity");
}
};
}
}
以及依赖于此的Pair类
package osm2spacebook;
public class Pair<T1,T2>{
public T1 v1;
public T2 v2;
public Pair(T1 t1,T2 t2){
v1=t1;
v2=t2;
}
}
完整的错误信息
Exception in thread "main" java.lang.VerifyError: (class: osm2spacebook/MultiMap, method: position signature: (Ljava/lang/Object;)I) Incompatible object argument for function call
at osm2spacebook.SqlOutput.<init>(SqlOutput.java:64)
at osm2spacebook.OsmImport.<init>(OsmImport.java:142)
at osm2spacebook.OsmImport.main(OsmImport.java:280)
SqlOutput的第64行如下：
private MultiMap<Integer,Integer> edge_index=new MultiMap<Integer,Integer>();