Java string.format（）僅工作一半

Question

我正在嘗試使用string.format（）構造一個字符串，但是它在一半時間內停止工作（剛剛結束）。

private String constructMessage(String messageType, int messageCode,Position location) {
    double lat = location.getLat();
    double lon = location.getLon();
    double ele = location.getEle();
    double speed = 0.0;
    double heading = 0.0;

    String msg = "$PNGVEST," + messageType + "," + VEST_ID + ","
            + System.currentTimeMillis() + "," + lat + "," + lon + "," + ele
            + "," + speed + "," + heading + "," + messageCode;

    String test = String.format("$PNGVEST,%s,%d,%d,%f,%f,%f,$f,$f,$d",
            messageType, VEST_ID, System.currentTimeMillis(), lat, lon, ele,
            speed, heading, messageCode);

    System.out.println(msg);
    System.out.println(test);
    return msg;
}

當我運行上面的代碼時，得到以下輸出：

$PNGVEST,LOCATION,1,1439998967553,51.558641765246364,-3.043043462354341,-1.0,0.0,0.0,0
$PNGVEST,LOCATION,1,1439998967553,51.558642,-3.043043,-1.000000,$f,$f,$d
$PNGVEST,LOCATION,1,1439998968553,51.55862560874394,-3.043027770590568,-1.0,0.0,0.0,0
$PNGVEST,LOCATION,1,1439998968553,51.558626,-3.043028,-1.000000,$f,$f,$d

為什么不格式化最后三個變量？

Answer 1

您使用最后3個變量進行了拼寫錯誤。 您注意到$f和$d而不是%f和%d 。

它應該是 ：

String test = String.format("$PNGVEST,%s,%d,%d,%f,%f,%f,%f,%f,%d",
        messageType, VEST_ID, System.currentTimeMillis(), lat, lon, ele,
        speed, heading, messageCode);

代替

String.format("$PNGVEST,%s,%d,%d,%f,%f,%f,$f,$f,$d", ...);

Answer 2

嘗試改變

String test = String.format("$PNGVEST,%s,%d,%d,%f,%f,%f,$f,$f,$d",
        messageType, VEST_ID, System.currentTimeMillis(), lat, lon, ele,
        speed, heading, messageCode);

至

String test = String.format("$PNGVEST,%s,%d,%d,%f,%f,%f,%f,%f,%d",
        messageType, VEST_ID, System.currentTimeMillis(), lat, lon, ele,
        speed, heading, messageCode);