1.launch.js代码：

// launch: update files

var __failCount = 0;
var AssetsManager = cc.Scene.extend({
    _am: null,
    _progress: null,
    _percent: 0,
    _percentByFile: 0,
    run: function () {

        // windows may not need update
        var not_update;
        if (cc.sys.os == sys.OS_WINDOWS) {
            not_update = 1;
        }

        if (not_update || !cc.sys.isNative) {
            this.loadGame();
            return;
        }

        var layer = new cc.Layer();
        this.addChild(layer);
        this._progress = new cc.LabelTTF.create("下载进度：0%", "Arial", 12);
        this._progress.x = cc.winSize.width / 2;
        this._progress.y = cc.winSize.height / 2 + 50;
        layer.addChild(this._progress);

        // android: /data/data/com.huanle.magic/files/  
        var storagePath = (jsb.fileUtils ? jsb.fileUtils.getWritablePath() : "./");// storagePath表示本地的存储目录，更新的文件将下载到此目录下，程序加载脚本和资源时，也将优先从此目录查询  
        this._am = new jsb.AssetsManager("res/project.manifest", storagePath);
        this._am.retain();

        if (!this._am.getLocalManifest().isLoaded()) {
            cc.log("Fail to update assets, step skipped.");
            this.loadGame();
        } else {
            var that = this;
            var listener = new jsb.EventListenerAssetsManager(this._am, function (event) {
                switch (event.getEventCode()) {
                    case jsb.EventAssetsManager.ERROR_NO_LOCAL_MANIFEST:
                        cc.log("No local manifest file found, skip assets update.");
                        that.loadGame();
                        break;
                    case jsb.EventAssetsManager.UPDATE_PROGRESSION:
                        that._percent = event.getPercent();
                        that._percentByFile = event.getPercentByFile();
                        cc.log(that._percent + "%");

                        var msg = event.getMessage();
                        if (msg) {
                            cc.log(msg);
                        }
                        break;
                    case jsb.EventAssetsManager.ERROR_DOWNLOAD_MANIFEST:
                    case jsb.EventAssetsManager.ERROR_PARSE_MANIFEST:
                        cc.log("Fail to download manifest file, update skipped.");
                        that.loadGame();
                        break;
                    case jsb.EventAssetsManager.ALREADY_UP_TO_DATE:
                    case jsb.EventAssetsManager.UPDATE_FINISHED:
                        cc.log("Update finished.");
                        that.loadGame();
                        break;
                    case jsb.EventAssetsManager.UPDATE_FAILED:
                        cc.log("Update failed. " + event.getMessage());

                        __failCount++;
                        if (__failCount < 5) {
                            that._am.downloadFailedAssets();
                        } else {
                            cc.log("Reach maximum fail count, exit update process");
                            __failCount = 0;
                            that.loadGame();
                        }
                        break;
                    case jsb.EventAssetsManager.ERROR_UPDATING:
                        cc.log("Asset update error: " + event.getAssetId() + ", " + event.getMessage());
                        that.loadGame();
                        break;
                    case jsb.EventAssetsManager.ERROR_DECOMPRESS:
                        cc.log(event.getMessage());
                        that.loadGame();
                        break;
                    default:
                        break;
                }
            });

            cc.eventManager.addListener(listener, 1);
            this._am.update();
            cc.director.runScene(this);
        }

        this.schedule(this.updateProgress, 0.5);
    },
    loadGame: function () {
        cc.loader.loadJs(["src/game.js"], function (err) {
            if (err) {
                cc.log("error:" + err);
            } else {
                // run game logic
                game.run();
            }
        });
    },
    updateProgress: function (dt) {
        this._progress.string = "下载进度：" + this._percent + "%";
    },
    onExit: function () {
        this._am.release();
        this._super();
    }
});

2.配置文件

在客户端的res目录下添加project.manifest：

{  
    "packageUrl" : "http://192.168.1.103/bw",
    "remoteManifestUrl" : "http://192.168.1.103/bw/project.manifest",
    "remoteVersionUrl" : "http://192.168.1.103/bw/version.manifest",
    "version" : "1.0.0",
    "groupVersions" : {
        "1" : "1.0.0"  
    }  
} 

project.manifest：

{  
    "packageUrl" : "http://192.168.1.103/bw",  
    "remoteManifestUrl" : "http://192.168.1.103/bw/project.manifest",  
    "remoteVersionUrl" : "http://192.168.1.103/bw/version.manifest", 
    "version" : "1.0.5",  
    "groupVersions" : {  
        "1" : "1.0.5"  
    },
    "engineVersion" : "3.0 rc0",  
    "assets" : {  
        "src/app.zip" : {
			"md5" : "6809C100A369FD8A79A97208B0278A2B",
            "compressed" : true,
            "group" : "1"  
        }  
    },  
    "searchPaths" : [  
        "src/"
	]  
} 

{
	"packageUrl" : "http://192.168.1.103/bw",
	"remoteManifestUrl" : "http://192.168.1.103/bw/project.manifest",
	"remoteVersionUrl" : "http://192.168.1.103/bw/version.manifest",
	"version" : "1.0.5",
	"groupVersions": {
		"1" : "1.0.5"
	},
	"engineVersion" : "3.0 rc0"
}

cocos3——4.js热更新