为什么我的循环只走一次,只导出同一天同一个的第一次查询的记录,应该是导出同一天同一个人的所有记录

private Runnable dodownload() throws IOException {
return new Runnable() {
@Override
public void run() {
String basepath = getResourceBasePath();
List tfeepaids = getTfeepaidByTime();
String timeName = getOneDayForDown();
String KjDownResourcePath = "";
String id = "";
for (Tfeepaid tfeepaid : tfeepaids) {
id = tfeepaid.getFcertid();
KjDownResourcePath = new File(basepath, "down/" + id + "-" + timeName + ".txt").getAbsolutePath();
ensureDirectory(KjDownResourcePath);
StringBuffer sb = new StringBuffer();
sb.append(tfeepaid.getFlastcommit());
sb.append("\t");
sb.append("\r\n");
// TODO 其他数据据字段的设置20190314
try {
BufferedWriter bw = new BufferedWriter(
new OutputStreamWriter(new FileOutputStream(KjDownResourcePath)));
bw.write(sb.toString());
bw.flush();
bw.close();
} catch (IOException e) {
e.printStackTrace();
}

            }

        }
    };
}

从代码得知，取出来的集合

List tfeepaids = getTfeepaidByTime();

是全部用户数据的话，直接遍历，因为KjDownResourcePath的路径相同，所以后面的一定会将前面的内容覆盖掉。
所以可以将同一个用户的数据，放在list集合中，然后使用用户id当key，放于map中。
然后再通过key，遍历map，一次性取出用户的集合数据，输出到文档。

private Runnable dodownload() throws IOException {
        return new Runnable() {
            public void run() {
                String basepath = getResourceBasePath();
                List<Tfeepaid> tfeepaids = getTfeepaidByTime();
                String timeName = getOneDayForDown();
                String KjDownResourcePath = "";

                // 将同一个用户的数据，放在list集合中，然后使用用户id当key，放于map中。
                Map<String, List<Tfeepaid>> tfeepaidMap = new HashMap<String, List<Tfeepaid>>();
                for (Tfeepaid tfeepaid : tfeepaids) {
                    List<Tfeepaid> tfeepaidList = tfeepaidMap.get(tfeepaid.getFcertid());
                    if (tfeepaidList == null) {
                        tfeepaidList = new ArrayList<Tfeepaid>();
                    }
                    tfeepaidList.add(tfeepaid);
                    tfeepaidMap.put(tfeepaid.getFcertid(), tfeepaidList);
                }

                Set<String> keys = tfeepaidMap.keySet();

                // 通过key，遍历map，取出集合数据，输出到文档。
                for (String key : keys) {
                    List<Tfeepaid> tfeepaidList = tfeepaidMap.get(key);

                    KjDownResourcePath = new File(basepath, "down/" + key + "-" + timeName + ".txt").getAbsolutePath();
                    ensureDirectory(KjDownResourcePath);

                    StringBuffer sb = new StringBuffer();
                    // 输出数据为Flastcommit，也可以拼接其他数据。
                    for (Tfeepaid tfeepaid : tfeepaidList) {
                        sb.append(tfeepaid.getFlastcommit());
                        sb.append("\r\n");
                    }

                    try {
                        BufferedWriter bw = new BufferedWriter(
                                new OutputStreamWriter(new FileOutputStream(KjDownResourcePath)));
                        bw.write(sb.toString());
                        bw.flush();
                        bw.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        };
    }