java.lang.OutOfMemoryError即使很多

我正在尝试将2.5GB的txt文件读入我的应用程序.我正在运行Win7 x64并且有43GB的内存可用(64GB).我尝试使用-Xmx -XX：MaxParmSize -XX：ParmSize等.这些都不会影响错误.我还能尝试什么？这个错误看起来很奇怪,因为我当然有足够的堆空间可用.

Exception in thread "main" java.lang.OutOfMemoryError: Requested array size exceeds VM limit
    at java.util.Arrays.copyOf(Unknown Source)
    at java.lang.AbstractStringBuilder.expandCapacity(Unknown Source)
    at java.lang.AbstractStringBuilder.ensureCapacityInternal(Unknown Source)
    at java.lang.AbstractStringBuilder.append(Unknown Source)
    at java.lang.StringBuilder.append(Unknown Source)
    at j.utilities.IO.loadString(IO.java:187)
    at j.utilities.IO.loadString(IO.java:169)
    at city.PreProcess.main(PreProcess.java:78)

我在跑步

java version "1.7.0_09"
Java(TM) SE Runtime Environment (build 1.7.0_09-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.5-b02,mixed mode)

非常感谢提前.

==============答案==============

好的,我只是测试了它

StringBuilder sb = new StringBuilder();
for ( int i=1; i<Integer.MAX_VALUE; i++ )
    sb.append("x");

得到了

Exception in thread "main" java.lang.OutOfMemoryError: Requested array size exceeds VM limit
at java.util.Arrays.copyOf(Unknown Source)
...

因此,它确实是StringBuilder,它试图构建一个大于Integer.MAX_VALUE的数组.

万一感兴趣

StringBuilder sb = new StringBuilder();
int i=1;
try {
    for ( ; i<Integer.MAX_VALUE; i++ )
        sb.append("x");
} catch ( OutOfMemoryError e ) {
    System.out.println(i); // OUTPUT: 1207959551
    System.out.println(Integer.MAX_VALUE); // OUTPUT: 2147483647
}

使用StringBuilder,您可以累积1,207,959,550个字符 – 远小于Integer.MAX_VALUE.