在 Java 中将长值转换为数组

Question

我
• 有两个长数组列表，我正在比较两个数组 id这是相同的，然后我想将其转换为 int 的数组[]，但是我做不到。这是我的代码，请帮助我

最喜欢的学校

   public ArrayList<Long> favSchool() {
        school_id.clear();
        Cursor mCursor = db.selectQuery("SELECT * FROM  fav_school");
        if (mCursor.moveToFirst()) {
            {
                do {
                    school_id.add(mCursor.getLong(mCursor
                            .getColumnIndex("school_id")));
                } while (mCursor.moveToNext());
            }
            mCursor.close();
        }
        return school_id;
    }
    // All Schools
    public ArrayList<Long> allSchool() {
        school_id.clear();
        Cursor mCursor = db.selectQuery("SELECT * FROM  all_school");
        if (mCursor.moveToFirst()) {
            {
                do {
                    school_id.add(mCursor.getLong(mCursor
                            .getColumnIndex("school_id")));
                } while (mCursor.moveToNext());
            }
            mCursor.close();
        }
        return school_id;
    }

   the code where I am comparing both arraylists
        if (favSchool() != null) {
    for (int j = 0; j < favSchool().size(); j++) {
        System.out.println("Equals..: " + allSchool().get(j));
            }
        } 
   I want to save the result in this int[] savedStatus.

Answer 1

尝试这样的事情

ArrayList<Long> favschool = favSchool();
    ArrayList<Long> allschool = allSchool();
    ArrayList<Long> comonschool = new ArrayList<Long>();
    if (favSchool() != null) {
        for (int j = 0; j < favschool.size(); j++) {
            for (int i = 0; i < allschool.size(); i++) {
                if (favschool.get(j) == allschool.get(i)) {
                    comonschool.add(favschool.get(j));
                }
            }
        }
    }
    Long[] commonSchool1 = new Long[comonschool.size()]; 
    for (int i = 0; i < comonschool.size(); i++) {
        commonSchool1[i] = comonschool.get(i);
    }