public interface Callback<T, E> {
// in: 回傳的資料
public void back(T in);
// 錯誤時要做的事
// err 錯誤訊息
public void error(E err);
}
//----------------------------------------
public class Server_1 {
public Thread asyncGetData(Callback callback) {
out.println("server start");
Thread th_1 = new Thread(() -> {
int time = (int) (Math.random() * 5000);
out.printf("server thread start(%s)\n", time);
try {
Thread.sleep(time);
// 回傳資料
callback.back(time);
out.printf("server thread end(%s)\n", time);
} catch (InterruptedException ex) {
callback.error(ex);
}
});
th_1.start();
return th_1;
}
}
//----------------------------------------
public class Client_1 {
// 資料交換用
int switchData_int;
public void getData(){
out.println("client.getData()");
Server_1 server_1 = new Server_1();
int gg;
Thread th_1 = server_1.asyncGetData(new Callback<Integer, Error>() {
@Override
public void back(Integer in) {
out.println("callback.back");
// 閉包只適用於套嵌的 class
Client_1.this.switchData_int = in;
}
@Override
public void error(Error err) {
}
});
try {
th_1.join();
} catch (InterruptedException ex) {
out.println(ex);
}
out.printf("result(%s)\n------------\n", this.switchData_int);
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
Client_1 cl = new Client_1();
cl.getData();
cl.getData();
}
}
