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Java 解决MongoDB错误_Java_Mongodb - Fatal编程技术网

Java 解决MongoDB错误

Java 解决MongoDB错误,java,mongodb,Java,Mongodb,有人能帮我吗?您正在尝试将DBObject分配给BasicDBObject。基本上是将泛型类型分配给特定类型。这是不允许的。将您的列表更改为list或obj为BasicDBObject如果有用,请接受我的回答:) public List<DBObject> findByDateDescending(int limit) { List<BasicDBObject> posts = null; // XXX HW 3.2, Work Here //

有人能帮我吗?

您正在尝试将
DBObject
分配给
BasicDBObject
。基本上是将泛型类型分配给特定类型。这是不允许的。将您的列表更改为
list
obj
BasicDBObject

如果有用,请接受我的回答:)
public List<DBObject> findByDateDescending(int limit) {

    List<BasicDBObject> posts = null;
    // XXX HW 3.2,  Work Here
    // Return a list of DBObjects, each one a post from the posts collection
    BasicDBObject query = new BasicDBObject();

    BasicDBObject sortPredicate = new BasicDBObject();
    sortPredicate.put("date", -1);

    DBCursor cur = postsCollection.find(query).sort(sortPredicate);

    int i = 0;
    while( cur.hasNext() && i < limit ) {
        if ( posts == null)
            posts = new ArrayList<BasicDBObject>();

        DBObject obj = cur.next();
        posts.add(obj);
        System.out.println("findByDateDescending(" + limit + " blog entry " + obj);
        i++;
    }

    return posts;
}
add(com.mongodb.BasicDBObject)List cannot be applied to com.mongodb.DBObject.