理解栈溢出与堆溢出之二：Java堆内存空间不足引发的OutOfMemoryError

堆中主要存放的是对象。

堆溢出：不断的new对象会导致堆中空间溢出。如果虚拟机的栈内存允许动态扩展，当扩展栈容量无法申请到足够的内存时。

【示例】：

public class HeapError {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();

        try {
            while (true) {
                list.add("Floweryu");
            }
        } catch (Throwable e) {
            System.out.println(list.size());
            e.printStackTrace();
        }
    }
}

【输出】：

解决方法：调整堆的大小：Xmx

-Xmx size

Specifies the maximum size (in bytes) of the memory allocation pool in bytes. This value must be a multiple of 1024 and greater than 2 MB. Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, and g or G to indicate gigabytes. The default value is chosen at runtime based on system configuration. For server deployments, -Xms and -Xmx are often set to the same value. The following examples show how to set the maximum allowed size of allocated memory to 80 MB by using various units:

-Xmx83886080
-Xmx81920k
-Xmx80m

The -Xmx option is equivalent to -XX:MaxHeapSize.

设置-Xmx256M后，输入如下，比之前小：