04 2020 档案
摘要：@Override public void run(String... args) throws Exception { ConcurrentHashMap<String, String> concurrentHashMap = new ConcurrentHashMap<>(); concurre
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摘要：解释执行：即逐条将字节码翻译成机器码并执行，无需等待编译，非热点代码（80%） 即时执行：将一个方法中包含的所有字节码编译成机器码后再执行，实际运行速度更快，热点代码采用这个方法（20%）。
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摘要：max-http-header-size设置 server.max-http-header-size=999999999 //953m JVM参数配置 -Xms800m -Xmx800m 写一个rest api @RestController("action") public class HttpH
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摘要：一、Sublist导致OOM 代码 @Slf4j public class SubListDemo { public static void subListOOM() { List<List<Integer>> data = new ArrayList<>(); for (int i = 0; i
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摘要：坑1，用Array.asList转换基础类型数组 代码 @Slf4j public class ArrayAsListDemo { public static void intArrayToList() { int[] arr = {1, 2, 3}; List list = Arrays.asLi
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摘要：实体类 class Point { private int x; private int y; public int getX() { return x; } public void setX(int x) { this.x = x; } public int getY() { return y;
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摘要：代码 @Slf4j public class StringCompareDemo { public static void compare() { String a = "1"; String b = "1"; log.info("\nString a = \"1\";\n" + "String b
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摘要：实例级别的锁 实例代码 @Slf4j public class AddCompareDemo { private int a, b; public void add() { for (int i = 0; i < 10000; i++) { a++; b++; } } public void com
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摘要：ThreadLocal ThreadLocal 适用于变量在线程间隔离，而在方法或类间共享的场景。 代码 1 @RestController 2 public class ThreadLocalController { 3 private static final ThreadLocal<Strin
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摘要：newFixedThreadPool @Slf4j public class TheadPoolDemo { private static ThreadPoolExecutor threadPool = (ThreadPoolExecutor) Executors.newFixedThreadPoo
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摘要：代码 1 @Slf4j 2 public class IntegerCompare { 3 public static void doCompare() { 4 5 Integer a = 127; //Integer.valueOf(127) 6 Integer b = 127; //Intege
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