五花八门的内存溢出

// -Xms20m -Xmx20m
private static void heapOutOfMemory() {
    List list = new ArrayList();
    while (true) {
        list.add(new Object());
    }
}

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
	at java.util.Arrays.copyOf(Arrays.java:3210)
	at java.util.Arrays.copyOf(Arrays.java:3181)
	at java.util.ArrayList.grow(ArrayList.java:265)
	at java.util.ArrayList.ensureExplicitCapacity(ArrayList.java:239)
	at java.util.ArrayList.ensureCapacityInternal(ArrayList.java:231)
	at java.util.ArrayList.add(ArrayList.java:462)
	at outofmemory.OutOfMemoryDemo.heapOutOfMemory(OutOfMemoryDemo.java:27)
	at outofmemory.OutOfMemoryDemo.main(OutOfMemoryDemo.java:15)

private static void stackOverflowError() {
    stackOverflowError();
}

Exception in thread "main" java.lang.StackOverflowError
	at outofmemory.OutOfMemoryDemo.stackOverflowError(OutOfMemoryDemo.java:39)
	at outofmemory.OutOfMemoryDemo.stackOverflowError(OutOfMemoryDemo.java:39)
	at outofmemory.OutOfMemoryDemo.stackOverflowError(OutOfMemoryDemo.java:39)

/**
 * 操作系统给java进程的内存是有限的,-堆占用的空间-方法去占用的空间-减去直接内存和虚拟机本身占用的就是虚拟机栈和本地方法栈的
 * 程序计数器占用的很小可以忽略不计
 * Xss为每个线程占用的,当Xss越大就越容易耗光栈的总空间,造成无法创建线程
 * 注意:据说这段代码有可能造成机器假死,跑之前要保存当前工作(Windows系统java线程是映射到操作系统内核线程上的)
 * -Xss20m
 */
private static void stackOverflowError2() {
    while (true) {
        new Thread(() -> {
            while (true) {
            }
        }).start();
    }
}

java.lang.OutOfMemoryError: unable to create new native thread

/**
 * 常量池溢出
 * -Xms6m -Xmx6m
 * 这个能证明是运行时常量池OOM吗???
 */
private static void runtimeConstantPoolOOM() {
	Set<String> set = new HashSet<>();
	int i = 0;
	while (true) {
		i++;
		set.add(String.valueOf(i).intern());
	}
}

-XX:MetaspaceSize=12M -XX:MaxMetaspaceSize=12M 

Exception in thread "background-preinit" java.lang.OutOfMemoryError: Metaspace
Exception in thread "main" java.lang.OutOfMemoryError: Metaspace