Java8中的并行流使用
```java
public class StreamTest {
public List<Person> constructPersons() {
List<Person> persons = new ArrayList<Person>();
for (int i = 0; i < 5; i++) {
Person p = new Person(i, "name" + i, "sex" + i, i);
persons.add(p);
}
return persons;
}
/**
* for
*
* @param persons
*/
public void doFor(List<Person> persons) {
long start = System.currentTimeMillis();
for (Person p : persons) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
System.out.println(p.name);
}
long end = System.currentTimeMillis();
System.out.println("doFor cost:" + (end - start));
}
/**
* 顺序流
*
* @param persons
*/
public void doStream(List<Person> persons) {
long start = System.currentTimeMillis();
persons.stream().forEach(x -> {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
System.out.println(x.name);
});
long end = System.currentTimeMillis();
System.out.println("doStream cost:" + (end - start));
}
/**
* 并行流
*
* @param persons
*/
public void doParallelStream(List<Person> persons) {
long start = System.currentTimeMillis();
persons.parallelStream().forEach(x -> {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
System.out.println(x.name);
});
long end = System.currentTimeMillis();
System.out.println("doParallelStream cost:" + (end - start));
}
public static void main(String[] args) {
StreamTest streamTest = new StreamTest();
List<Person> personList = streamTest.constructPersons();
streamTest.doFor(personList);
streamTest.doStream(personList);
streamTest.doParallelStream(personList);
}
public static void main1(String[] args) {
Snowflake snowflake = IdUtil.getSnowflake(1, 1);
long id = snowflake.nextId();
List<String> orderNos = Collections.synchronizedList(new ArrayList<String>());
IntStream.range(0,10000000).parallel().forEach(i->{
orderNos.add(snowflake.nextId()+"");
});
System.out.println(orderNos.size());
}
```