How to parse huge JSON file in Android?
When I parse such file I see on something like this on logs:
04-05 15:55:46.490: DEBUG/dalvikvm(3847): GC freed 12159 objects / 557744 bytes in 142ms
04-05 15:55:46.490: INFO/global(3847): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required.
04-05 15:55:46.650: DEBUG/dalvikvm(3847): GC freed 56 objects / 100176 bytes in 115ms
04-05 15:55:46.660: INFO/dalvikvm-heap(3847): Grow heap (frag case) to 4.207MB for 110626-byte allocation
04-05 15:55:46.760: DEBUG/dalvikvm(3847): GC freed 0 objects / 0 bytes in 104ms
04-05 15:55:46.890: DEBUG/dalvikvm(3847): GC freed 3 objects / 73856 bytes in 115ms
04-05 15:55:47.050: DEBUG/dalvikvm(3847): GC freed 7 objects / 110872 bytes in 113ms
04-05 15:55:47.050: INFO/dalvikvm-heap(3847): Grow heap (frag case) to 4.426MB for 248896-byte allocation
04-05 15:55:47.150: DEBUG/dalvikvm(3847): GC freed 0 objects / 0 bytes in 104ms
04-05 15:55:47.310: DEBUG/dalvikvm(3847): GC freed 8 objects / 166232 bytes in 106ms
04-05 15:55:47.310: INFO/dalvikvm-heap(3847): Grow heap (frag case) to 4.624MB for 373340-byte allocation
04-05 15:55:47.420: DEBUG/dalvikvm(3847): GC freed 0 objects / 0 bytes in 106ms
04-05 15:55:47.580: DEBUG/dalvikvm(3847): GC freed 10 objects / 249288 bytes in 111ms
04-05 15:55:47.590: INFO/dalvikvm-heap(3847): Grow heap (frag case) to 4.920MB for 560006-byte allocation
04-05 15:55:47.690: DEBUG/dalvikvm(3847): GC freed 0 objects / 0 bytes in 98ms
04-05 15:55:47.810: DEBUG/dalvikvm(3847): GC freed 12 objects / 373792 bytes in 88ms
04-05 15:55:47.910: DEBUG/dalvikvm(3847): GC freed 4 objects / 560088 bytes in 87ms
04-05 15:55:48.010: DEBUG/dalvikvm(3847): GC freed 5 objects / 128 bytes in 88ms
04-05 15:55:48.010: INFO/dalvikvm-heap(3847): Grow heap (frag case) to 5.350MB for 461302-byte allocation
04-05 15:55:48.130: DEBUG/dalvikvm(3847): GC freed 0 objects / 0 bytes in 120ms
04-05 15:55:48.990: DEBUG/dalvikvm(3847): GC freed 10419 objects / 1383992 bytes in 109ms
04-05 15:55:49.720: DEBUG/dalvikvm(3847): GC freed 8769 objects / 384360 bytes in 115ms
04-05 15:55:50.550: DEBUG/dalvikvm(3847): GC freed 10472 objects / 454880 bytes in 129ms
04-05 15:55:51.590: DEBUG/dalvikvm(3847): GC freed 12663 objects / 554440 bytes in 147ms
Is there a pull parser for Json files? How to deal with such thing?
Take a look at the Jackson JSON parser, it's faster than the one in Android, and faster than GSON, and supports streaming.
I do however reiterate the point made by others that your JSON is HUGE and that does suggest a non-optimal design. e.g. if the connection is wonky and it fails a few times you could cause your user to incur additional data costs on a mobile data plan. Always better to break it down where possible so failure doesn't involve requesting the whole lot again.
You might look into JsonStreamParser in gson if you are looking for an interface that streams json objects instead of parsing everything immediately.
来源：https://stackoverflow.com/questions/5553101/parsing-huge-json-object-in-android