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Spring-core 5.0.8

asm

• ASM is an all purpose Java bytecode manipulation and analysis framework.

• ASM是一个万能的java字节码操纵和分析框架

• asm官网

• ASM和访问者模式

• ASM库的介绍和使用

cglib

• Byte Code Generation Library is high level API to generate and transform JAVA byte code

• 高层级的生成和转换Java字节码的字节码生成库

• cglib github地址

objenesis

• Objenesis is a small Java library that serves one purpose:To instantiate a new object of a particular class.

• Objenesis是一个只为特殊类初始化对象小型Java库

• objenesis官网

lang

• 定义八个注解

  • NonNull.class

  • NonNullApi.class

  • NonNullFields.class

  • Nullable.class

  • UsesJava7.class

  • UsesJava8.class

  • UsesSunHttpServer.class

  • UsesSunMisc.class

util

backoff

重试算法

• 定义退避算法

  • BackOff.class

  • BackOffExecution.class

  • ExponentialBackOff.class 指数重试间隔实现

  • FixedBackOff.class 固定重试间隔实现

• 用于封装重试逻辑

使用说明

 BackOffExecution exec = backOff.start();
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 // In the operation recovery/retry loop:
 long waitInterval = exec.nextBackOff();
 if (waitInterval == BackOffExecution.STOP) {
     // do not retry operation
 }
 else {
     // sleep, e.g. Thread.sleep(waitInterval)
     // retry operation
 }
 }

测试代码

package com.zby.util.backoff;
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import java.util.Date;
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import org.springframework.util.backoff.BackOff;
import org.springframework.util.backoff.BackOffExecution;
import org.springframework.util.backoff.ExponentialBackOff;
import org.springframework.util.backoff.FixedBackOff;
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public class BackoffDemo {
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  public static void main(String[] args) throws Exception {
    //BackOff backOff = new FixedBackOff(1000, 10);
    BackOff backOff = new ExponentialBackOff(500, 2);
    BackOffExecution backOffExecution = backOff.start();
    int successTime=7;
    for(int i=0;;i++) {
      System.out.println("重试："+backOffExecution);
      long waitInterval = backOffExecution.nextBackOff();
      if (waitInterval == BackOffExecution.STOP) {
        System.out.println("执行失败：" + backOffExecution);
        break;
      } else {
        Thread.sleep(waitInterval);
        System.out.println("准备执行操作，当前时间："+new Date());
        boolean success = operation(successTime==i);
        if(success) {
          break;
        }
      }
    }
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  }
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  public static boolean operation(boolean success) {
    System.out.println("执行结果："+success);
    return success;
  }
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}
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• 可以封装一下把公共代码封装起来，提供重试机制，如：

package com.zby.util.backoff;
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import java.util.Date;
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import org.springframework.util.backoff.BackOff;
import org.springframework.util.backoff.BackOffExecution;
import org.springframework.util.backoff.FixedBackOff;
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public abstract class FixedBackOffRunnable implements Runnable{
  
  private BackOffExecution backOffExecution;
  
  public FixedBackOffRunnable(long interval, long maxAttempts) {
    BackOff backOff = new FixedBackOff(interval, maxAttempts);
    backOffExecution = backOff.start();
    
  }
  
  public void run() {
    while (true) {
      System.out.println("重试：" + backOffExecution);
      long waitInterval = backOffExecution.nextBackOff();
      if (waitInterval == BackOffExecution.STOP) {
        System.out.println("执行失败：" + backOffExecution);
        break;
      } else {
        try {
          Thread.sleep(waitInterval);
        } catch (InterruptedException e1) {
          e1.printStackTrace();
        }
        System.out.println("准备执行操作，当前时间：" + new Date());
        boolean retry=false;
        try {
          doRun();
        } catch (RetryableExeception e) {
          retry=true;
        }
        if(!retry) {