Android的NullPointerException异常而拷贝EXIF标签 [英] Android NullPointerException while copying exif tags

问题描述

我想重新大小的图像，该部分完成。
然后我试图EXIF标签复制到新文件。
我用ExifInterface读取标签。
我知道这是一个接口不是对象。
但是，当我尝试使用它的真正的大尺寸图像时，我得到 NullPointerException异常。
我得到这个错误并不适用于所有的图像。

I am trying to re-size an image, that part completed. Then I'm trying to copy exif tags to new file. I use ExifInterface to read tags. I know it's an interface not an object. But When I try to use it for really big sized image, I get NullPointerException. I get this error not for all the images.

07-25 11:59:23.870: WARN/System.err(1362): java.lang.NullPointerException
07-25 11:59:23.870: WARN/System.err(1362):     at android.media.ExifInterface.saveAttributes(ExifInterface.java:202)

我该如何解决呢？

How do I solve it?

code复制EXIF信息

Code to copy exif information

try {
    // copy paste exif information from original file to new
    // file
    ExifInterface oldexif = new ExifInterface(filePath);
    ExifInterface newexif = new ExifInterface(file.getPath());

    int build = Build.VERSION.SDK_INT;

    // From API 11
    if (build >= 11) {
        newexif.setAttribute("FNumber",
                oldexif.getAttribute("FNumber"));
        newexif.setAttribute("ExposureTime",
                oldexif.getAttribute("ExposureTime"));
        newexif.setAttribute("ISOSpeedRatings",
                oldexif.getAttribute("ISOSpeedRatings"));
    }
    // From API 9
    if (build >= 9) {
        newexif.setAttribute("GPSAltitude",
                oldexif.getAttribute("GPSAltitude"));
        newexif.setAttribute("GPSAltitudeRef",
                oldexif.getAttribute("GPSAltitudeRef"));
    }
    // From API 8
    if (build >= 8) {
        newexif.setAttribute("FocalLength",
                oldexif.getAttribute("FocalLength"));
        newexif.setAttribute("GPSDateStamp",
                oldexif.getAttribute("GPSDateStamp"));
        newexif.setAttribute("GPSProcessingMethod",
                oldexif.getAttribute("GPSProcessingMethod"));
        newexif.setAttribute("GPSTimeStamp",
                oldexif.getAttribute("GPSTimeStamp"));
    }
    newexif.setAttribute("DateTime",
            oldexif.getAttribute("DateTime"));
    newexif.setAttribute("Flash", oldexif.getAttribute("Flash"));
    newexif.setAttribute("GPSLatitude",
            oldexif.getAttribute("GPSLatitude"));
    newexif.setAttribute("GPSLatitudeRef",
            oldexif.getAttribute("GPSLatitudeRef"));
    newexif.setAttribute("GPSLongitude",
            oldexif.getAttribute("GPSLongitude"));
    newexif.setAttribute("GPSLongitudeRef",
            oldexif.getAttribute("GPSLongitudeRef"));

    // You need to update this with your new height width
    newexif.setAttribute("ImageLength",
            oldexif.getAttribute("ImageLength"));
    newexif.setAttribute("ImageWidth",
            oldexif.getAttribute("ImageWidth"));

    newexif.setAttribute("Make", oldexif.getAttribute("Make"));
    newexif.setAttribute("Model", oldexif.getAttribute("Model"));
    newexif.setAttribute("Orientation",
            oldexif.getAttribute("Orientation"));
    newexif.setAttribute("WhiteBalance",
            oldexif.getAttribute("WhiteBalance"));

    newexif.saveAttributes();

    Toast.makeText(getApplicationContext(),
            "Image resized & saved successfully",
            Toast.LENGTH_SHORT).show();
} catch (Exception e) {
    e.printStackTrace();
}

更多信息onFly：

Additional onFly information:

创建新文件时，我试图同时读取该文件：

New file is created when I'm trying to read both the file:

在oldexif调试手表

Debug watch on oldexif

在newexif调试手表

Debug watch on newexif

测试图片

HTTP：//vikaskanani.files.word$p$ pss.com/2011/07/test.jpg

使用Android模拟器的SDK 2.1

Using Android emulator for sdk 2.1

推荐答案

您是在什么地方saveAttributes传递一个空值。

You are passing a null value somewhere in the saveAttributes.

调试NullPointerException异常是很容易的，为您提供有源$ C ​​$ C。

Debugging NullPointerExceptions is very easy, providing you have the sourcecode.

下面你可以找到源头code为ExifInterface为Android 2.1

Below you can find the sourcecode for the ExifInterface for Android 2.1

<一个href=\"http://grep$c$c.com/file/repository.grep$c$c.com/java/ext/com.google.android/android/2.1_r2/android/media/ExifInterface.java#ExifInterface\" rel=\"nofollow\">http://grep$c$c.com/file/repository.grep$c$c.com/java/ext/com.google.android/android/2.1_r2/android/media/ExifInterface.java#ExifInterface

线202包含此：

sb.append(val.length() + " ");

唯一可以为空这里是VAL。 （你在saveAttributes方法传递的一个值）。

Only thing that can be null here is val. (one of the values you're passing in the saveAttributes method).

我会建议您检查一下你传递到该值的价值，并观看了空值。

I would suggest double checking the values you're passing onto that value, and watch out for null values.

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