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                                  一、栈溢出StackOverflowError
	栈是线程私有的,生命周期与线程相同,每个方法在执行的时候都会创建一个栈帧,用来存储局部变量表,操作数栈,动态链接,方法出口等信息。 
	栈溢出:方法执行时创建的栈帧个数超过了栈的深度。 
	原因举例:方法递归 
	【示例】: 
	
		
			
				
					
						
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public class StackError {
    private int i = 0;
    public void fn() {
        System.out.println(i++);
        fn();
    }
    public static void main(String[] args) {
        StackError stackError = new StackError();
        stackError.fn();
    }
} |  
	【输出】: 
	 
	解决方法:调整JVM栈的大小:-Xss 
	
		-Xss size 
		Sets the thread stack size (in bytes). Append the letter k or K to indicate KB, m or M to indicate MB, and g or G to indicate GB. The default value depends on the platform:Linux/x64 (64-bit): 1024 KBmacOS (64-bit): 1024 KBOracle Solaris/x64 (64-bit): 1024 KBWindows: The default value depends on virtual memory 
		The following examples set the thread stack size to 1024 KB in different units: 
		-Xss1m-Xss1024k
 -Xss1048576
 
		This option is similar to -XX:ThreadStackSize. 
	在IDEA中点击Run菜单的Edit Configuration如下图: 
	 
	设置后,再次运行,会发现i的值变小,这是因为设置的-Xss值比原来的小: 
	 
	二、堆溢出OutOfMemoryError:Java heap space
 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】: 
	
		
			
				
					
						
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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: 
	 
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