常用于多线程场景,待多线程都结束后方可继续主线程逻辑处理
CodeConstant 常量类
import java.util.HashMap;
import java.util.Map;
public class CodeConstant {
public static final Map<String, Map<String, String>> CODE = new HashMap<>();
static {
//资产1
CODE.put(AssetTypeEnum.ZICHAN_1.getCode(),
new HashMap<String, String>() {{
put("JS", "JS1");
put("CHECK", "CHECK1");
put("PUBLISH", "PUBLISH1");
}});
//资产2
CODE.put(AssetTypeEnum.ZICHAN_2.getCode(),
new HashMap<String, String>() {{
put("JS", "JS1");
put("CHECK", "CHECK2");
put("PUBLISH", "PUBLISH2");
}});
}
}
CountDownLatchController
import com.example.demo.constant.CodeConstant;
import com.example.demo.service.TestCountDownLatchService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
@RestController
@RequestMapping("/countDownLatch")
public class CountDownLatchController {
private static final Logger logger = LoggerFactory.getLogger(CountDownLatchController.class);
@Autowired
private TestCountDownLatchService downLatchService;
@PostMapping("/test")
public void testCountDownLatch() {
logger.info("测试多线程开始...");
try {
List<String> list = Arrays.asList("zichan1", "zichan2", "zichan3");
CountDownLatch countDownLatch = new CountDownLatch(2);
Map<String, Map<String, String>> map = CodeConstant.CODE;
for (String type : list) {
downLatchService.test(type, map, countDownLatch);
}
countDownLatch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
logger.info("测试多线程结束...");
}
}
TestCountDownLatchService 类
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
@Service
public class TestCountDownLatchService {
private static final Logger logger = LoggerFactory.getLogger(TestCountDownLatchService.class);
@Async
public void test(String type, Map<String, Map<String, String>> map, CountDownLatch countDownLatch) {
Map<String, String> typeMap = map.get(type);
if (typeMap == null) {
countDownLatch.countDown();
return;
}
try {
logger.info("类型{}的信息{}", type, typeMap);
for (int i = 0; i < 1000; i++) {
for (int j = 0; j < 1000; j++) {
logger.debug("i*j={}", i * j);
}
}
} catch (Exception e) {
logger.error("类型{}异常:", type, e);
} finally {
countDownLatch.countDown();
}
}
}
启动类上补充注解 @EnableAsync
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableAsync;
@EnableAsync
@SpringBootApplication
@MapperScan(basePackages = { "com.example.demo" })
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
测试结果
可以看出,主线程执行"测试多线程开始"后,开启了两个子线程,等待子线程全部完成后,主线程继续执行"测试多线程结束";