原文:http://blog.csdn.net/jenny8080/article/details/52100312
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;public class App { public static void main(String[] args) {
try {
List<String> list = new ArrayList<String>();
for (int i = 0; i < 1000; i++) {
list.add(i + ",");
} System.out.println(list2Str(list, 5));
} catch (Exception e) {
e.printStackTrace();
}
}
public static String list2Str(List<String> list, final int nThreads)
throws Exception {
if (list == null || list.isEmpty()) {
return null;
}
StringBuffer ret = new StringBuffer(); int size = list.size();
ExecutorService executorService = Executors.newFixedThreadPool(nThreads);
List<Future<String>> futures = new ArrayList<Future<String>>(nThreads);
for (int i = 0; i < nThreads; i++) {
final List<String> subList = list.subList(size / nThreads * i, size/ nThreads * (i + 1));
Callable<String> task = new Callable<String>() {
public String call() throws Exception {
StringBuffer sb = new StringBuffer();
for (String str : subList) {
sb.append(str);
}
return sb.toString();
}
};
futures.add(executorService.submit(task));
} for (Future<String> future : futures) {
ret.append(future.get());
}
executorService.shutdown(); return ret.toString();
}}