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Exception in thread “main” java.lang.OutOfMemoryError: Java heap space

at java.util.Arrays.copyOfRange(Arrays.java:3209)

at java.lang.String.<init>(String.java:216)

at java.io.BufferedReader.readLine(BufferedReader.java:331)

at java.io.BufferedReader.readLine(BufferedReader.java:362)

at fileCompare.main(fileCompare.java:54)

Java Result: 1

如果程序本身没有问题，如内存溢出等，那解决办法是增加heap size。

Netbean用户：

http://developers.sun.com/docs/javacaps/installing/jcapsinstall.inst_increase_heap_size_t.html

http://wiki.netbeans.org/FaqSettingHeapSize

http://performance.netbeans.org/howto/jvmswitches/index.html

Two JVM options are often used to tune JVM heap size:

-Xmx

for maximum heap size, and

-Xms

for initial heap size. Here are some common mistakes I have seen when using them:

• Missing
  
m, M, g

  or
  
G

  at the end (they are case insensitive). For example,
  

  java -Xmx128 BigApp
  
  java.lang.OutOfMemoryError: Java heap space
  
  
  

  The correct command should be:
  
java -Xmx128m BigApp

  . To be precise,
  
-Xmx128

  is a valid setting for very small apps, like HelloWorld. But in real life, I guess you really mean
  
-Xmx128m


• Extra space in JVM options, or incorrectly use =. For example,
  

  java -Xmx 128m BigApp
  
  Invalid maximum heap size: -Xmx
  
  Could not create the Java virtual machine.
  
  
  
  java -Xmx=512m HelloWorld
  
  Invalid maximum heap size: -Xmx=512m
  
  Could not create the Java virtual machine.
  
  
  

  The correct command should be
  
java -Xmx128m BigApp

  , with no whitespace nor =. -X options are different than -Dkey=value system properties, where = is used.

• Only setting