我正在尝试读取两个文件，加入其内容然后GZIP，以便将其发送到服务器。
当文件分别为几MB时，一切都很好，但当其中一个文件的重量约为30MB（生产预期大小）时，尝试读取它时会出现Out of memory on a 43628012-byte allocation错误。我不知道我做错了什么，因为它适用于较小的文件。
接下来是我用来读取文本文件的代码：
private String getTextFromFile(File fileName) {
StringBuilder logsHolder = new StringBuilder();
BufferedReader input;
try {
input = new BufferedReader(new FileReader(fileName));
String line = null;
String lineSeparator = System.getProperty("line.separator");
while ((line = input.readLine()) != null){
logsHolder.append(line);
logsHolder.append(lineSeparator);
}
input.close();
} catch (IOException e) {
e.printStackTrace();
}
return logsHolder.toString();
}
在读取数千行后，错误将在logsHolder.append(line);行上启动。接下来是LogCat输出：
01-04 09:54:25.852: D/dalvikvm(888): GC_FOR_ALLOC freed 1223K, 29% free 6002K/8364K, paused 21ms, total 21ms
01-04 09:54:25.892: D/dalvikvm(888): GC_FOR_ALLOC freed 1022K, 30% free 6235K/8860K, paused 16ms, total 17ms
01-04 09:54:25.932: D/dalvikvm(888): GC_FOR_ALLOC freed 884K, 27% free 6481K/8860K, paused 18ms, total 19ms
01-04 09:54:25.932: I/dalvikvm-heap(888): Grow heap (frag case) to 8.521MB for 1134874-byte allocation
01-04 09:54:25.952: D/dalvikvm(888): GC_FOR_ALLOC freed 738K, 32% free 6851K/9972K, paused 18ms, total 18ms
01-04 09:54:26.012: D/dalvikvm(888): GC_FOR_ALLOC freed 586K, 32% free 6851K/9972K, paused 18ms, total 18ms
01-04 09:54:26.012: I/dalvikvm-heap(888): Grow heap (frag case) to 9.422MB for 1702306-byte allocation
01-04 09:54:26.042: D/dalvikvm(888): GC_FOR_ALLOC freed 1108K, 37% free 7405K/11636K, paused 20ms, total 20ms
01-04 09:54:26.122: D/dalvikvm(888): GC_FOR_ALLOC freed 878K, 37% free 7405K/11636K, paused 21ms, total 21ms
01-04 09:54:26.122: I/dalvikvm-heap(888): Grow heap (frag case) to 10.776MB for 2553454-byte allocation
01-04 09:54:26.152: D/dalvikvm(888): GC_CONCURRENT freed 0K, 30% free 9899K/14132K, paused 10ms+2ms, total 27ms
01-04 09:54:26.152: D/dalvikvm(888): WAIT_FOR_CONCURRENT_GC blocked 17ms
01-04 09:54:26.242: D/dalvikvm(888): GC_FOR_ALLOC freed 2980K, 42% free 8236K/14132K, paused 16ms, total 16ms
01-04 09:54:26.252: I/dalvikvm-heap(888): Grow heap (frag case) to 12.805MB for 3830176-byte allocation
01-04 09:54:26.282: D/dalvikvm(888): GC_CONCURRENT freed 0K, 33% free 11977K/17876K, paused 10ms+3ms, total 27ms
01-04 09:54:26.282: D/dalvikvm(888): WAIT_FOR_CONCURRENT_GC blocked 8ms
01-04 09:54:26.432: D/dalvikvm(888): GC_FOR_ALLOC freed 4470K, 47% free 9483K/17876K, paused 17ms, total 17ms
01-04 09:54:26.442: I/dalvikvm-heap(888): Grow heap (frag case) to 15.849MB for 5745260-byte allocation
01-04 09:54:26.472: D/dalvikvm(888): GC_CONCURRENT freed 0K, 36% free 15094K/23488K, paused 17ms+2ms, total 33ms
01-04 09:54:26.472: D/dalvikvm(888): WAIT_FOR_CONCURRENT_GC blocked 15ms
01-04 09:54:26.663: D/dalvikvm(888): GC_FOR_ALLOC freed 6704K, 52% free 11353K/23488K, paused 20ms, total 20ms
01-04 09:54:26.683: I/dalvikvm-heap(888): Grow heap (frag case) to 20.415MB for 8617886-byte allocation
01-04 09:54:26.713: D/dalvikvm(888): GC_CONCURRENT freed 0K, 39% free 19769K/31904K, paused 17ms+2ms, total 32ms
01-04 09:54:26.713: D/dalvikvm(888): WAIT_FOR_CONCURRENT_GC blocked 14ms
01-04 09:54:27.033: D/dalvikvm(888): GC_FOR_ALLOC freed 10057K, 56% free 14158K/31904K, paused 31ms, total 31ms
01-04 09:54:27.053: I/dalvikvm-heap(888): Grow heap (frag case) to 27.264MB for 12926824-byte allocation
01-04 09:54:27.093: D/dalvikvm(888): GC_CONCURRENT freed 8415K, 59% free 18366K/44528K, paused 17ms+2ms, total 32ms
01-04 09:54:27.093: D/dalvikvm(888): WAIT_FOR_CONCURRENT_GC blocked 15ms
01-04 09:54:27.333: D/dalvikvm(888): GC_CONCURRENT freed 4324K, 59% free 18367K/44528K, paused 1ms+3ms, total 29ms
01-04 09:54:27.333: D/dalvikvm(888): WAIT_FOR_CONCURRENT_GC blocked 22ms
01-04 09:54:27.493: D/dalvikvm(888): GC_FOR_ALLOC freed 2345K, 59% free 18366K/44528K, paused 19ms, total 19ms
01-04 09:54:27.513: I/dalvikvm-heap(888): Grow heap (frag case) to 37.537MB for 19390232-byte allocation
01-04 09:54:27.563: D/dalvikvm(888): GC_CONCURRENT freed 0K, 42% free 37302K/63464K, paused 34ms+4ms, total 51ms
01-04 09:54:27.563: D/dalvikvm(888): WAIT_FOR_CONCURRENT_GC blocked 15ms
01-04 09:54:28.094: D/dalvikvm(888): GC_FOR_ALLOC freed 20815K, 62% free 24678K/63464K, paused 40ms, total 40ms
01-04 09:54:28.234: D/dalvikvm(888): GC_FOR_ALLOC freed 1814K, 62% free 24678K/63464K, paused 22ms, total 23ms
01-04 09:54:28.284: I/dalvikvm-heap(888): Grow heap (frag case) to 52.947MB for 29085344-byte allocation
01-04 09:54:28.344: D/dalvikvm(888): GC_FOR_ALLOC freed 18935K, 63% free 34146K/91868K, paused 21ms, total 21ms
01-04 09:54:29.245: D/dalvikvm(888): GC_FOR_ALLOC freed 8191K, 63% free 34146K/91868K, paused 50ms, total 51ms
01-04 09:54:29.846: D/dalvikvm(888): GC_FOR_ALLOC freed 6821K, 63% free 34138K/91868K, paused 33ms, total 33ms
01-04 09:54:29.846: I/dalvikvm-heap(888): Forcing collection of SoftReferences for 43628012-byte allocation
01-04 09:54:29.866: D/dalvikvm(888): GC_BEFORE_OOM freed 76K, 63% free 34061K/91868K, paused 27ms, total 27ms
01-04 09:54:29.866: E/dalvikvm-heap(888): Out of memory on a 43628012-byte allocation.
我不知道压缩部分是否可以在如此大的缓冲区上工作，但目前我唯一的问题是阅读巨大的文本文件。
我希望你能帮助我找到为什么会失败，我应该改变什么才能使它发挥作用。
修改
接下来，如果我用来压缩两个文件的连接内容的代码：
File previousLog = SystemEventsReceiver.getPreviousLog();
if (previousLog.exists()) {
logsHolder.append(getTextFromFile(previousLog));
}
File currentLog = SystemEventsReceiver.getCurrentLog();
if (currentLog.exists()) {
logsHolder.append(getTextFromFile(currentLog));
}
Log.v("MyApp", "uncompressed logs: " + logsHolder.toString().getBytes().length);
// Compress logs.
byte[] compressedLogs = null;
try {
ByteArrayOutputStream os = new ByteArrayOutputStream(logsHolder.length());
GZIPOutputStream gos = new GZIPOutputStream(os);
gos.write(logsHolder.toString().getBytes());
gos.close();
compressedLogs = os.toByteArray();
os.close();
} catch (IOException e) {
e.printStackTrace();
}
Log.v("MyApp", "compressed logs: " + compressedLogs.length);
答案 0 :(得分：0)
感谢@ PhilW的评论，我提出了以下解决方案：
Log.v("MyApp", "reading logs");
// Get logs.
File previousLog = SystemEventsReceiver.getPreviousLog();
File currentLog = SystemEventsReceiver.getCurrentLog();
int completeLogSize = (int) (currentLog.length() + previousLog.length());
Log.v("MyApp", "uncompressed logs: " + completeLogSize);
// Compress logs.
byte[] compressedLogs = null;
try {
ByteArrayOutputStream os = new ByteArrayOutputStream(completeLogSize);
GZIPOutputStream gzipOS = new GZIPOutputStream(os);
if (previousLog.exists()) {
addLogToGZIP(previousLog, gzipOS);
}
if (currentLog.exists()) {
addLogToGZIP(currentLog, gzipOS);
}
gzipOS.close();
compressedLogs = os.toByteArray();
os.close();
} catch (IOException e) {
e.printStackTrace();
}
Log.v("MyApp", "compressed logs: " + compressedLogs.length);
private void addLogToGZIP(File logFile, GZIPOutputStream gzipOS) {
byte[] bytes = new byte[1024];
try {
BufferedInputStream buffer = new BufferedInputStream(new FileInputStream(logFile));
while (buffer.read(bytes, 0, bytes.length) != -1) {
gzipOS.write(bytes);
}
buffer.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
我从每个日志文件中读取字节并将其直接添加到GZIPOutputStream。
它适用于55MB文件（约1.100.000行）甚至100MB（~2.200.000行）的文件。