Disclaimer: I realize I can generate this at runtime in Java, this was needed for a very special case while performance testing some code. I've found a different approach, so now this is just more of a curiosity than anything practical.
I've tried the following as a static field, as an instance field, and initialized directly within the constructor. Every time eclipse is informing me that either "The code of constructor TestData() is exceeding the 65535 bytes limit" or "The code for the static initializer is exceeding the 65535 bytes limit".
There are 10,000 integers. If each int is 4 bytes (32bits), then would that not be 40,000 bytes? Is there really more that 25,0000 bytes of overhead in addition to the data just merely constructing the array?
The data is generated with this small bit of python:
#!/usr/bin/python
import random;
print "public final int[] RANDOM_INTEGERS = new int[] {";
for i in range(1,10000):
print str(int(random.uniform(0,0x7fffffff))) + ",";
print "};";
Here's a small sample:
public final int[] RANDOM_INTEGERS = new int[] {
963056418, 460816633, 1426956928, 1836901854, 334443802, 721185237, 488810483,
1734703787, 1858674527, 112552804, 1467830977, 1533524842, 1140643114, 1452361499,
716999590, 652029167, 1448309605, 1111915190, 1032718128, 1194366355, 112834025,
419247979, 944166634, 205228045, 1920916263, 1102820742, 1504720637, 757008315,
67604636, 1686232265, 597601176, 1090143513, 205960256, 1611222388, 1997832237,
1429883982, 1693885243, 1987916675, 159802771, 1092244159, 1224816153, 1675311441,
1873372604, 1787757434, 1347615328, 1868311855, 1401477617, 508641277, 1352501377,
1442984254, 1468392589, 1059757519, 1898445041, 1368044543, 513517087, 99625132,
1291863875, 654253390, 169170318, 2117466849, 1711924068, 564675178, 208741732,
1095240821, 1993892374, 87422510, 1651783681, 1536657700, 1039420228, 674134447,
1083424612, 2137469237, 1294104182, 964677542, 1506442822, 1521039575, 64073383,
929517073, 206993014, 466196357, 1139633501, 1692533218, 1934476545, 2066226407,
550646675, 624977767, 1494512072, 1230119126, 1956454185, 1321128794, 2099617717,
//.... to 10,0000 instances
Here is the bytecode for initializing an array with {1000001, 1000002, 1000003}:
5 iconst_3
6 newarray int [10]
8 dup
9 iconst_0
10 ldc <Integer 1000001> [12]
12 iastore
13 dup
14 iconst_1
15 ldc <Integer 1000002> [13]
17 iastore
18 dup
19 iconst_2
20 ldc <Integer 1000003> [14]
22 iastore
23 putfield net.jstuber.test.TestArrayInitializingConstructor.data : int[] [15]
So for this small array each element requires 5 bytes of Java bytecode. For your bigger array both the array index and the index into the constant pool will use 3 bytes for most elements, which leads to 8 bytes per array element. So for 10000 elements you'd have to expect about 80kB of byte code.
The code for initializing big arrays with 16 bit indices looks like this:
2016 dup
2017 sipush 298
2020 ldc_w <Integer 100298> [310]
2023 iastore
2024 dup
2025 sipush 299
2028 ldc_w <Integer 100299> [311]