最近项目中协助做了个小的测试程序，需要拷贝文件。代码如下：
// fixed for raw data test.
private static final String RAW_DATA_TEST = "***123***";
private static final String EXTERNAL_STORAGE = "/mnt/sdcard2";
private static final String INTERNAL_STORAGE = "/mnt/sdcard";
private static final String RAW_DATA_CFG_FILE_NAME = "config.xml";
// fixed for raw data test.
static public boolean handleRawDataTest(Context context, String input) {
if (RAW_DATA_TEST.equals(input)) {
Log.d(TAG, "handleRawDataTest");
if (!copyRawDataCfgFile()) {
Log.d(TAG, "handleRawDataTest, get Raw Data Cfg file failed!");
Toast.makeText(context,
context.getString(R.string.raw_data_cfg_file_not_exist),
Toast.LENGTH_SHORT).show();
return false;
}
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.goodix.rawdata",
"com.goodix.rawdata.RawDataTest"));
context.startActivity(intent);
return true;
}
return false;
}
public static boolean copyRawDataCfgFile() {
String state = Environment.getExternalStorageState();
if (!Environment.MEDIA_MOUNTED.equals(state)) {
return false;
}
String srcFileName = EXTERNAL_STORAGE + File.separator + RAW_DATA_CFG_FILE_NAME;
String destFileName = INTERNAL_STORAGE + File.separator + RAW_DATA_CFG_FILE_NAME;
Log.d(TAG, "copyRawDataCfgFile, srcFileName = " + srcFileName + ", destFileName = " + destFileName);
try {
if (copyFile(srcFileName, destFileName, true)) {
Log.d(TAG, "copyRawDataCfgFile, successfull!");
return true;
}
} catch (Exception e) {
e.printStackTrace();
}
Log.d(TAG, "copyRawDataCfgFile, fail!");
return false;
}
public static boolean copyFile(String srcFileName, String destFileName, boolean reWrite)
throws IOException {
Log.d(TAG, "copyFile, begin");
File srcFile = new File(srcFileName);
File destFile = new File(destFileName);
if(!srcFile.exists()) {
Log.d(TAG, "copyFile, source file not exist.");
return false;
}
if(!srcFile.isFile()) {
Log.d(TAG, "copyFile, source file not a file.");
return false;
}
if(!srcFile.canRead()) {
Log.d(TAG, "copyFile, source file can't read.");
return false;
}
if(destFile.exists() && reWrite){
Log.d(TAG, "copyFile, before copy File, delete first.");
destFile.delete();
}
try {
InputStream inStream = new FileInputStream(srcFile);
FileOutputStream outStream = new FileOutputStream(destFile);
byte[] buf = new byte[1024];
int byteRead = 0;
while ((byteRead = inStream.read(buf)) != -1) {
outStream.write(buf, 0, byteRead);
}
outStream.flush();
outStream.close();
inStream.close();
} catch (IOException e) {
throw e;
} catch (Exception e) {
e.printStackTrace();
}
Log.d(TAG, "copyFile, success");
return true;
} 代码比较简单，但是中间报了个很奇怪的异常，纠结了很长时间，幸好在临下班前找到问题根结所在。记下这次事件，以此勉之。
异常如下：
01-01 00:14:31.070: E/StrictMode(3297): A resource was acquired at attached stack trace but never released. See java.io.Closeable for information on avoiding resource leaks. 01-01 00:14:31.070: E/StrictMode(3297): java.lang.Throwable: Explicit termination method 'close' not called 01-01 00:14:31.070: E/StrictMode(3297): at dalvik.system.CloseGuard.open(CloseGuard.java:184) 01-01 00:14:31.070: E/StrictMode(3297): at java.io.FileInputStream.<init>(FileInputStream.java:80) 01-01 00:14:31.070: E/StrictMode(3297): at com.android.dialer.SpecialCharSequenceMgr.copyFile(SpecialCharSequenceMgrProxy.java:768) 01-01 00:14:31.070: E/StrictMode(3297): at com.android.dialer.SpecialCharSequenceMgr.copyRawDataCfgFile(SpecialCharSequenceMgrProxy.java:702) 01-01 00:14:31.070: E/StrictMode(3297): at com.android.dialer.SpecialCharSequenceMgr.handleRawDataTest(SpecialCharSequenceMgrProxy.java:674) 01-01 00:14:31.070: E/StrictMode(3297): at com.android.dialer.SpecialCharSequenceMgr.handleCharsForTest(SpecialCharSequenceMgrProxy.java:618) 01-01 00:14:31.070: E/StrictMode(3297): at com.android.dialer.SpecialCharSequenceMgr.handleChars(SpecialCharSequenceMgrProxy.java:88) 01-01 00:14:31.070: E/StrictMode(3297): at com.android.dialer.dialpad.DialpadFragment.afterTextChanged(DialpadFragment.java:451) 01-01 00:14:31.070: E/StrictMode(3297): at android.widget.TextView.sendAfterTextChanged(TextView.java:7626) 01-01 00:14:31.070: E/StrictMode(3297): at android.widget.TextView$ChangeWatcher.afterTextChanged(TextView.java:9424)在网上也搜过“java.io.Closeable for information on avoiding resource leaks”和“java.lang.Throwable: Explicit termination method ‘close‘ not called”，都没找到和我这个问题类似的情况，一般都是cursor导致的内存泄漏的问题。最终，在反复查看代码才发现，原来问题的根结在我拷贝文件的目标目录未指定正确。出现问题的时候，我指定了INTERNAL_STORAGE为“/mnt/sdcard0”，在调用到new FileOutputStream(destFile)时会抛出异常，原因是并没有这个目录。手机内部存储根目录是“/mnt/sdcard”，这个路径实际指向了“/storage/sdcard0”。