三叶草 发表于 2021-9-18 13:24:02

浅谈Java(SpringBoot)基于zookeeper的分布式锁实现

这篇文章主要介绍了Java(SpringBoot)基于zookeeper的分布式锁实现,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们下面随着小编来一起学习学习吧
通过zookeeper实现分布式锁
1、创建zookeeper的client
首先通过curatorframeworkfactory创建一个连接zookeeper的连接curatorframework client


public class curatorfactorybean implements factorybean<curatorframework>, initializingbean, disposablebean {
private static final logger logger = loggerfactory.getlogger(contractfileinfocontroller.class);

private string connectionstring;
private int sessiontimeoutms;
private int connectiontimeoutms;
private retrypolicy retrypolicy;
private curatorframework client;

public curatorfactorybean(string connectionstring) {
this(connectionstring, 500, 500);
}

public curatorfactorybean(string connectionstring, int sessiontimeoutms, int connectiontimeoutms) {
this.connectionstring = connectionstring;
this.sessiontimeoutms = sessiontimeoutms;
this.connectiontimeoutms = connectiontimeoutms;
}

@override
public void destroy() throws exception {
logger.info("closing curator framework...");
this.client.close();
logger.info("closed curator framework.");
}

@override
public curatorframework getobject() throws exception {
return this.client;
}

@override
public class<?> getobjecttype() {
   return this.client != null ? this.client.getclass() : curatorframework.class;
}

@override
public boolean issingleton() {
return true;
}

@override
public void afterpropertiesset() throws exception {
if (stringutils.isempty(this.connectionstring)) {
   throw new illegalstateexception("connectionstring can not be empty.");
} else {
   if (this.retrypolicy == null) {
    this.retrypolicy = new exponentialbackoffretry(1000, 2147483647, 180000);
   }

   this.client = curatorframeworkfactory.newclient(this.connectionstring, this.sessiontimeoutms, this.connectiontimeoutms, this.retrypolicy);
   this.client.start();
   this.client.blockuntilconnected(30, timeunit.milliseconds);
}
}
public void setconnectionstring(string connectionstring) {
this.connectionstring = connectionstring;
}

public void setsessiontimeoutms(int sessiontimeoutms) {
this.sessiontimeoutms = sessiontimeoutms;
}

public void setconnectiontimeoutms(int connectiontimeoutms) {
this.connectiontimeoutms = connectiontimeoutms;
}

public void setretrypolicy(retrypolicy retrypolicy) {
this.retrypolicy = retrypolicy;
}

public void setclient(curatorframework client) {
this.client = client;
}
}
2、封装分布式锁
根据curatorframework创建interprocessmutex(分布式可重入排它锁)对一行数据进行上锁


public interprocessmutex(curatorframework client, string path) {
this(client, path, new standardlockinternalsdriver());
}
使用 acquire方法
1、acquire() :入参为空,调用该方法后,会一直堵塞,直到抢夺到锁资源,或者zookeeper连接中断后,上抛异常。
2、acquire(long time, timeunit unit):入参传入超时时间、单位,抢夺时,如果出现堵塞,会在超过该时间后,返回false。


public void acquire() throws exception {
if (!this.internallock(-1l, (timeunit)null)) {
throw new ioexception("lost connection while trying to acquire lock: " + this.basepath);
}
}

public boolean acquire(long time, timeunit unit) throws exception {
return this.internallock(time, unit);
}
释放锁 mutex.release();


public void release() throws exception {
thread currentthread = thread.currentthread();
interprocessmutex.lockdata lockdata = (interprocessmutex.lockdata)this.threaddata.get(currentthread);
if (lockdata == null) {
   throw new illegalmonitorstateexception("you do not own the lock: " + this.basepath);
} else {
   int newlockcount = lockdata.lockcount.decrementandget();
   if (newlockcount <= 0) {
    if (newlockcount < 0) {
   throw new illegalmonitorstateexception("lock count has gone negative for lock: " + this.basepath);
    } else {
   try {
      this.internals.releaselock(lockdata.lockpath);
   } finally {
      this.threaddata.remove(currentthread);
   }

    }
   }
}
}
封装后的dlock代码
1、调用interprocessmutex processmutex = dlock.mutex(path);
2、手动释放锁processmutex.release();
3、需要手动删除路径dlock.del(path);
推荐 使用:
都是 函数式编程
在业务代码执行完毕后 会释放锁和删除path
1、这个有返回结果
public t mutex(string path, zklockcallback zklockcallback, long time, timeunit timeunit)
2、这个无返回结果
public void mutex(string path, zkvoidcallback zklockcallback, long time, timeunit timeunit)


public class dlock {
private final logger logger;
private static final long timeout_d = 100l;
private static final string root_path_d = "/dlock";
private string lockrootpath;
private curatorframework client;

public dlock(curatorframework client) {
this("/dlock", client);
}

public dlock(string lockrootpath, curatorframework client) {
this.logger = loggerfactory.getlogger(dlock.class);
this.lockrootpath = lockrootpath;
this.client = client;
}
public interprocessmutex mutex(string path) {
if (!stringutils.startswith(path, "/")) {
   path = constant.keybuilder(new object[]{"/", path});
}

return new interprocessmutex(this.client, constant.keybuilder(new object[]{this.lockrootpath, "", path}));
}

public <t> t mutex(string path, zklockcallback<t> zklockcallback) throws zklockexception {
return this.mutex(path, zklockcallback, 100l, timeunit.milliseconds);
}

public <t> t mutex(string path, zklockcallback<t> zklockcallback, long time, timeunit timeunit) throws zklockexception {
string finalpath = this.getlockpath(path);
interprocessmutex mutex = new interprocessmutex(this.client, finalpath);

try {
   if (!mutex.acquire(time, timeunit)) {
    throw new zklockexception("acquire zk lock return false");
   }
} catch (exception var13) {
   throw new zklockexception("acquire zk lock failed.", var13);
}

t var8;
try {
   var8 = zklockcallback.doinlock();
} finally {
   this.releaselock(finalpath, mutex);
}

return var8;
}

private void releaselock(string finalpath, interprocessmutex mutex) {
try {
   mutex.release();
   this.logger.info("delete zk node path:{}", finalpath);
   this.deleteinternal(finalpath);
} catch (exception var4) {
   this.logger.error("dlock", "release lock failed, path:{}", finalpath, var4);
//   logutil.error(this.logger, "dlock", "release lock failed, path:{}", new object[]{finalpath, var4});
}

}

public void mutex(string path, zkvoidcallback zklockcallback, long time, timeunit timeunit) throws zklockexception {
string finalpath = this.getlockpath(path);
interprocessmutex mutex = new interprocessmutex(this.client, finalpath);

try {
   if (!mutex.acquire(time, timeunit)) {
    throw new zklockexception("acquire zk lock return false");
   }
} catch (exception var13) {
   throw new zklockexception("acquire zk lock failed.", var13);
}

try {
   zklockcallback.response();
} finally {
   this.releaselock(finalpath, mutex);
}

}

public string getlockpath(string custompath) {
if (!stringutils.startswith(custompath, "/")) {
   custompath = constant.keybuilder(new object[]{"/", custompath});
}

string finalpath = constant.keybuilder(new object[]{this.lockrootpath, "", custompath});
return finalpath;
}

private void deleteinternal(string finalpath) {
try {
   ((errorlistenerpathable)this.client.delete().inbackground()).forpath(finalpath);
} catch (exception var3) {
   this.logger.info("delete zk node path:{} failed", finalpath);
}

}

public void del(string custompath) {
string lockpath = "";

try {
   lockpath = this.getlockpath(custompath);
   ((errorlistenerpathable)this.client.delete().inbackground()).forpath(lockpath);
} catch (exception var4) {
   this.logger.info("delete zk node path:{} failed", lockpath);
}

}
}


@functionalinterface
public interface zklockcallback<t> {
t doinlock();
}

@functionalinterface
public interface zkvoidcallback {
void response();
}

public class zklockexception extends exception {
public zklockexception() {
}

public zklockexception(string message) {
super(message);
}

public zklockexception(string message, throwable cause) {
super(message, cause);
}
}
配置curatorconfig


@configuration
public class curatorconfig {
@value("${zk.connectionstring}")
private string connectionstring;

@value("${zk.sessiontimeoutms:500}")
private int sessiontimeoutms;

@value("${zk.connectiontimeoutms:500}")
private int connectiontimeoutms;

@value("${zk.dlockroot:/dlock}")
private string dlockroot;

@bean
public curatorfactorybean curatorfactorybean() {
return new curatorfactorybean(connectionstring, sessiontimeoutms, connectiontimeoutms);
}

@bean
@autowired
public dlock dlock(curatorframework client) {
return new dlock(dlockroot, client);
}
}
测试代码


@restcontroller
@requestmapping("/dlock")
public class lockcontroller {

@autowired
private dlock dlock;

@requestmapping("/lock")
public map testdlock(string no){
final string path = constant.keybuilder("/test/no/", no);
long mutex=0l;
try {
   system.out.println("在拿锁:"+path+system.currenttimemillis());
    mutex = dlock.mutex(path, () -> {
    try {
   system.out.println("拿到锁了" + system.currenttimemillis());
   thread.sleep(10000);
   system.out.println("操作完成了" + system.currenttimemillis());
    } finally {
   return system.currenttimemillis();
    }
   }, 1000, timeunit.milliseconds);
} catch (zklockexception e) {
   system.out.println("拿不到锁呀"+system.currenttimemillis());
}
return collections.singletonmap("ret",mutex);
}

@requestmapping("/dlock")
public map testdlock1(string no){
final string path = constant.keybuilder("/test/no/", no);
long mutex=0l;
try {
   system.out.println("在拿锁:"+path+system.currenttimemillis());
   interprocessmutex processmutex = dlock.mutex(path);
   processmutex.acquire();
   system.out.println("拿到锁了" + system.currenttimemillis());
   thread.sleep(10000);
   processmutex.release();
   system.out.println("操作完成了" + system.currenttimemillis());
} catch (zklockexception e) {
   system.out.println("拿不到锁呀"+system.currenttimemillis());
   e.printstacktrace();
}catch (exception e){
   e.printstacktrace();
}
return collections.singletonmap("ret",mutex);
}
@requestmapping("/del")
public map deldlock(string no){
final string path = constant.keybuilder("/test/no/", no);
dlock.del(path);
return collections.singletonmap("ret",1);
}
}
以上所述是小编给大家介绍的java(springboot)基于zookeeper的分布式锁实现详解整合,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对CodeAE代码之家网站的支持!
原文链接:https://blog.csdn.net/LJY_SUPER/article/details/87807091

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