Java 将方法作为参数传递

1、前言

在通过WebSocket向浏览器发送数据时，需要发送3种数据到页面上，写3个方法感觉太冗余，故想到了JDK1.8的lambda表达式和Function<T, R>实现Java把方法作为参数传递

2、上代码

package com.ruoyi.project.front.comService;
 
import com.ruoyi.project.manage.param_set.mapper.ParamSetMapper;
import com.ruoyi.project.socket.webSocket.BeamWebSocket;
import com.ruoyi.project.socket.webSocket.LighterWebSocket;
import com.ruoyi.project.socket.webSocket.RollerWebSocket;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
 
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.function.Function;
 
@Component
public class SendToWebHelper {
    @Autowired
    private ParamSetMapper paramSetMapper;
    private static int index = 0;
    private static Integer hz = 5;
 
    public void sendToWeb() {
        sendToWeb("lighter", (s) -> LighterWebSocket.sendMessageToAllClient(s));
        sendToWeb("roller", (s) -> RollerWebSocket.sendMessageToAllClient(s));
        sendToWeb("beam", (s) -> BeamWebSocket.sendMessageToAllClient(s));
    }
 
    private void sendToWeb(String dir, Function<String, String> function) {
        String imgFileDir = paramSetMapper.getParamByCode("imgFileDir").getParamValue();
        String nginxServer = paramSetMapper.getParamByCode("nginxServer").getParamValue();
        File file = new File(imgFileDir + "/" + dir);
        if (!file.exists() || file.listFiles() == null || file.listFiles().length <= 0) {
            System.out.println(dir + " dir empty");
            return;
        }
        List<String> list = new ArrayList<>();
        for (File f1 : file.listFiles()) {
            list.add(f1.getName());
        }
 
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                try {
                    String webPath = nginxServer + "/" + dir + "/" + list.get(index) + "";
                    if (index++ >= list.size() - 1) {
                        index = 0;
                    }
                    function.apply(webPath);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }, 0, 1000 / hz);
    }
}