Question

我不得不将以下法典模式移至 Java。我很想知道,在 Java与任何图书馆或没有:

async def call_external_service(user):  
    async with session.get(url, headers=headers) as response:  
    response = await response.json()  
    # extract some field from the response  
    country = response.json()[ country ]  
    print(country)

async def get_countries(users):  
    tasks = [asyncio.ensure_future(call_external_service(user)) for user in users]  
    await asyncio.gather(*tasks, return_exceptions=True)

users = list()  
with open("users.txt", "r") as f:  
    for line in f.readlines():  
    users.append(line.strip( 
 ))

asyncio.run(get_countries(users))

增编

Answer 1

在 Java21年及以后,virtual threads,几乎不需要复杂的合成/反应式方案规划。你们可以有数百万条虚拟的线索,可以直截了当。

Java有HTTP客户类别。

Java有方便的有资源自动关闭资源,如<代码> Executorservice。

Collection < User > users = … ; // Fetch. 
try
(
    ExecutorService es = Executors.newVirtualThreadPerTaskExecutor() ;
)
{
    for ( User : user ) 
    { 
        es.submit( … some task object — `Runnable` or `Callable` … ) ;
    }
}
// Flow-of-control stops here (blocks) until all submitted tasks complete/fail.

如果你愿意,上述所有法典都可以放在<条码>可兰经<>条码>内,作为在另一条执行器服务中另一条镜子的任务。

更多学习。这些专题已在Stack Overflow上广泛论述。

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