java - 合并两个ArrayList

Question

我有两个ArrayList

1. ArrayList<Integer> data = new ArrayList<Integer>();
2. ArrayList<Integer> temp = new ArrayList<Integer>();

在第一个数组中，我有 1-60 之间的条目(某些数字丢失)。第二个数组中是那些缺失的数字。

我想打印所有条目，例如......

存在的内容将显示为 1 --- Y

那些缺失的会出现如 12 --- N

这是我的代码:

writer=new PrintWriter(new FileWriter(file,true));
                    for(int i=1;i<60;i++){
                        for(int missing:temp){
                        if(missing==i){
                            writer.println(i+"   +++++++++++++++++   N");
                        }
                        else{
                            writer.println(i+"   ---   Y");
                        }
                    }
                }

但我的输出是这样的:

1 --- Y

1 --- Y

2 --- Y

2 --- Yand so on.....

Answer 1

你的问题似乎有点令人困惑......但你可能想要这个:

for (int actual = 1; actual <= 60; actual ++) {
    // number present in DATA list
    if (data.contains(actual)) {
        writer.println(actual + "   ---   Y");
    // number present in TEMP list
    } else if (temp.contains(actual)) {
        writer.println(actual + "   ---   N");
    // number not present in ANY list
    } else {
        writer.println(actual + "   -------");
    }
}

<小时/>

输出:

1   ---   Y
2   ---   Y
3   ---   N
4   ---   Y
5   ---   Y
6   ---   Y
7   ---   N
8   ---   N
9   -------
10   -------
11   -------

等等...

<小时/>

添加:

记住关闭编写器:

writer.close();

在使用FileWritter的方式中，内容将附加在文件末尾，在构造函数中使用false:

PrintWriter writer = new PrintWriter(new FileWriter(file, false));

<小时/>

测试一下!

public class Q37024973 {
    public static void main(String[] args) throws Exception {
        ArrayList<Integer> data = new ArrayList<Integer>();
        data.add(1);
        data.add(2);
        data.add(4);
        data.add(5);
        data.add(6);
        ArrayList<Integer> temp = new ArrayList<Integer>();
        temp.add(3);
        temp.add(7);
        temp.add(8);

        File file = new File("C:\\tmp\\Q37024973.txt");

        PrintWriter writer = new PrintWriter(new FileWriter(file, true));

        for (int actual = 1; actual <= 60; actual ++) {
            if (data.contains(actual)) {
                writer.println(actual + "   ---   Y");
            } else if (temp.contains(actual)) {
                writer.println(actual + "   ---   N");
            } else {
                writer.println(actual + "   -------");
            }
        }

        writer.close();
    }
}