Java 创建csv会导致崩溃_Java_Android

Java 创建csv会导致崩溃

java android

Java 创建csv会导致崩溃,java,android,Java,Android,因此，我试图让我的android应用程序创建一个CSV文件，但它似乎不起作用，并且崩溃了。我已经测试了我的其余代码，它工作正常，但这似乎太容易导致崩溃：/csv文件在我手机的根目录上是空的更新了我的日志我的代码： FileWriter writefile; File root = Environment.getExternalStorageDirectory(); File MesurementFile= new File(root, "Data.csv"); Calendar c = Ca

因此，我试图让我的android应用程序创建一个CSV文件，但它似乎不起作用，并且崩溃了。我已经测试了我的其余代码，它工作正常，但这似乎太容易导致崩溃：/csv文件在我手机的根目录上是空的

更新了我的日志我的代码：

FileWriter writefile;
File root = Environment.getExternalStorageDirectory();
File MesurementFile= new File(root, "Data.csv");
Calendar c = Calendar.getInstance();
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String formattedDate = df.format(c.getTime());
String date = "Current date";
String a= "a size : ";
String b="b Size : ";

public void writeCsvHeader() throws IOException {
    String line = String.format("%s,%s,%s\n",date,a,b);
    writer = new FileWriter(csvfile);
    writer.write(line);
}

public void writeCsvData(long a, long b)throws IOException {
    String line = String.format("%f,%f,%f,%f\n", formattedDate ,a,b);
    writer.write(line);
    try {

        writer = new FileWriter(MesurementFile);
        writeCsvData(a,b);

    } catch (IOException e) {
        e.printStackTrace();
    }
}}

堆栈跟踪：

07-25 14:07:54.874: E/AndroidRuntime(9482): FATAL EXCEPTION: main
07-25 14:07:54.874: E/AndroidRuntime(9482): Process: com.extras, PID: 9482
07-25 14:07:54.874: E/AndroidRuntime(9482): java.lang.RuntimeException: Unable to start service com.extras.MyService@41e9c500 with Intent { cmp=com.extras/.MyService (has extras) }: java.util.IllegalFormatConversionException: %f can't format java.lang.String arguments
07-25 14:07:54.874: E/AndroidRuntime(9482):     at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2737)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at android.app.ActivityThread.access$2100(ActivityThread.java:144)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1302)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at android.os.Handler.dispatchMessage(Handler.java:102)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at android.os.Looper.loop(Looper.java:136)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at android.app.ActivityThread.main(ActivityThread.java:5140)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.lang.reflect.Method.invokeNative(Native Method)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.lang.reflect.Method.invoke(Method.java:515)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:611)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at dalvik.system.NativeStart.main(Native Method)
07-25 14:07:54.874: E/AndroidRuntime(9482): Caused by: java.util.IllegalFormatConversionException: %f can't format java.lang.String arguments
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.util.Formatter.badArgumentType(Formatter.java:1489)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.util.Formatter.transformFromFloat(Formatter.java:2038)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.util.Formatter.transform(Formatter.java:1465)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.util.Formatter.doFormat(Formatter.java:1081)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.util.Formatter.format(Formatter.java:1042)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.util.Formatter.format(Formatter.java:1011)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.lang.String.format(String.java:1999)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at java.lang.String.format(String.java:1973)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at com.extras.MyService.writeCsvData(MyService.java:83)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at com.extras.MyService.onStartCommand(MyService.java:46)
07-25 14:07:54.874: E/AndroidRuntime(9482):     at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2720)
07-25 14:07:54.874: E/AndroidRuntime(9482):     ... 10 more





 07-25 14:24:25.994: E/AndroidRuntime(13219): FATAL EXCEPTION: main
    07-25 14:24:25.994: E/AndroidRuntime(13219): Process: com.extras, PID: 13219
    07-25 14:24:25.994: E/AndroidRuntime(13219): java.lang.StackOverflowError
    07-25 14:24:25.994: E/AndroidRuntime(13219):    at     java.lang.Thread.currentThread(Thread.java:470)
    07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.lang.ThreadLocal.get(ThreadLocal.java:53)
    07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.util.Formatter.getDecimalFormat(Formatter.java:594)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at     java.util.Formatter.transformF(Formatter.java:2215)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.util.Formatter.transformFromFloat(Formatter.java:2055)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.util.Formatter.transform(Formatter.java:1465)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.util.Formatter.doFormat(Formatter.java:1081)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.util.Formatter.format(Formatter.java:1042)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.util.Formatter.format(Formatter.java:1011)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.lang.String.format(String.java:1999)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at java.lang.String.format(String.java:1973)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:83)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writeCsvData(MyService.java:88)
07-25 14:24:25.994: E/AndroidRuntime(13219):    at com.extras.MyService.writ

您正在使用%f格式化字符串，因此它正在抱怨。还有四个%f，您正在传递三个值（formattedDate、a、b）

%f无法格式化java.lang.String参数

这基本上说明了你需要的一切。您试图写入一个字符串，但占位符只接受

%f

，即

float

（如果我没有记错的话）

因此，只需检查此处的参数类型，并将

%f

更改为

%s

或更改参数类型即可

// at least one %f is wrong here...
String line = String.format("%f,%f,%f,%f\n", formattedDate ,a,b);

更新：

您现在看到一个

StackOverflowException

，因为您在同一个方法中调用了自己的方法。这是一个无限循环，通常称为“递归”。递归需要有一些定义良好、防弹的结束条件。堆栈大小是递归可以执行的循环的限制，您正在超过该限制

public void writeCsvData(long a, long b)throws IOException {
    String line = String.format("%f,%f,%f,%f\n", formattedDate ,a,b);
    writer.write(line);
    try {

        writer = new FileWriter(MesurementFile);
        writeCsvData(a,b); // THIS cause the loop

    } catch (IOException e) {
        e.printStackTrace();
    }
}

您需要找到一种只写一行并在循环中重复调用的方法。如何做到这一点取决于您：）

原因：

java.util.IllegalFormatConversionException:%f

无法格式化

java.lang.String

参数

我在这里看到三个问题：

您正在使用

%f

（浮点格式），同时传递

long

值（无浮点）

您的格式需要四个参数，您只传递三个参数

formattedDate

是一个

字符串

，它不是用于浮点数的

%f的可格式化字符串


请包括堆栈跟踪。无论如何，考虑使用CSV库编写CSVSI已经考虑使用OpenCsv或SuffCSV，但我宁愿尝试从零开始代码更改自己的文件（“%s，%f，%f”）没有帮助：/同样的问题，更新我的栈
public void writeCsvData(long a, long b)throws IOException {
    String line = String.format("%f,%f,%f,%f\n", formattedDate ,a,b);
    writer.write(line);
    try {

        writer = new FileWriter(MesurementFile);
        writeCsvData(a,b); // THIS cause the loop

    } catch (IOException e) {
        e.printStackTrace();
    }
}

String line = String.format("%f,%f,%f,%f\n", formattedDate ,a,b);