导出内存映象文件

内存映象文件导出的2种方式

• 内存溢出自动导出
  • -XX:+HeapDumpOnOutOfMemoryError
  • -XX:HeapDumpPath=./
• 使用jmap命令手动导出

内存映象文件导出示例

自动导出

@RestController
public class DemoController {

    List<User> userList = new ArrayList<>();
    List<Class<?>> classList = new ArrayList<>();

    /**
     * -Xmx32M -Xms32M
     * -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=./
     * @return
     */
    @GetMapping("/heap")
    public String heap() {
        int i = 0;
        while (true) {
            userList.add(new User(i++, UUID.randomUUID().toString()));
        }
    }

}

输出：

java.lang.OutOfMemoryError: Java heap space
Dumping heap to ./\java_pid17776.hprof ...
Heap dump file created [44356196 bytes in 0.272 secs]
Exception in thread "http-nio-8088-exec-1" java.lang.OutOfMemoryError: Java heap space

jmap手动导出

PS C:\Users\LiXinlei\Desktop> jmap -dump:format=b,file=heap.hprof 17452
Dumping heap to C:\Users\LiXinlei\Desktop\heap.hprof ...
Heap dump file created