java.lang.OutOfMemory错误: Java heap space in jasper report

Question

当我以 doc 格式导出内容时，出现 java 堆空间错误，

java.lang.OutOfMemoryError: Java heap space
    at java.util.Arrays.copyOf(Unknown Source)
    at java.io.ByteArrayOutputStream.write(Unknown Source)
    at sun.nio.cs.StreamEncoder.writeBytes(Unknown Source)
    at sun.nio.cs.StreamEncoder.implWrite(Unknown Source)
    at sun.nio.cs.StreamEncoder.write(Unknown Source)
    at sun.nio.cs.StreamEncoder.write(Unknown Source)
    at java.io.OutputStreamWriter.write(Unknown Source)
    at java.io.Writer.write(Unknown Source)

Answer 1

最好加一个

-XX:+HeapDumpOnOutOfMemoryError

每当发生 OutOfMemoryError 时创建堆转储，然后分析堆转储，例如: Eclipse Memory Analyzer它会显示对象的数量，并且通常会清楚地识别导致 OutOfMemory 错误的对象。