【java.lang.OutOfMemoryError】OutOfMemoryError often occurs when serializing large objects

[baiyapeng]

Gson version

2.10

Java / Android version

Java version: 1.8.0_60 JVM: Java HotSpot(TM) 64-Bit Server VM (25.60-b23, mixed mode)

Used tools

• [ ] SpringBoot

Description

When serializing some objects, such as XmlWebApplicationContext (and I don't know why it is serialized), it often happens that

Expected behavior

normal execution

Actual behavior

java.lang.OutOfMemoryError occurs

Reproduction steps

Exception stack trace

The following is taken from the hprof file：

at java.lang.OutOfMemoryError.<init>(OutOfMemoryError.java:48)
    at java.util.Arrays.copyOf(Arrays.java:3332)
       Local Variable: char[]#146777
    at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:137)
    at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:121)
    at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:421)
    at java.lang.StringBuffer.append(StringBuffer.java:272)
       Local Variable: java.lang.StringBuffer#12
    at java.io.StringWriter.write(StringWriter.java:101)

[baiyapeng]

Dear Gson Team, I checked and found that there should be more char[] objects, but I don’t know why they are not recycled. Is it a jvm problem or a Gson problem, or other suggestions, thank you very much

[eamonnmcmanus]

It might be better to ask this question on StackOverflow, with the gson tag.

[baiyapeng]

In fact, the reason has been located, it is the problem that happened here(when stringbuffer increases capacity)：

private int newCapacity(int minCapacity) {
        // overflow-conscious code
        int newCapacity = (value.length << 1) + 2;
        if (newCapacity - minCapacity < 0) {
            newCapacity = minCapacity;
        }
        return (newCapacity <= 0 || MAX_ARRAY_SIZE - newCapacity < 0)
            ? hugeCapacity(minCapacity)
            : newCapacity;
    }

private int hugeCapacity(int minCapacity) {
    if (Integer.MAX_VALUE - minCapacity < 0) { // overflow
        throw new OutOfMemoryError();
    }
    return (minCapacity > MAX_ARRAY_SIZE)
        ? minCapacity : MAX_ARRAY_SIZE;
}

@eamonnmcmanus You can close this issue, thank you very much for your support