大量 if...else 模式
使用极光推送的时候会有后台透传下来的消息，然后定义一个Type，安卓端根据这个Type去处理逻辑，所以在JPushReceiver里面的代码就存在大量的if...else...判断。除开阅读难度不讲，每一次定义一个新的Type带来的工作量也是很大的，而且还有风险，其他的处理逻辑会不会受到影响。
if("toast".equals(type)){
//弹出toast
}else if("popup".equals(type)){
//弹出popup
}
使用责任链模式改造
1. 定义一个接口
public interface JPushInterceptor {
boolean intercept(String type, String extra);
}
2. 责任链
public class RealJPushInterceptor {
private List<JPushInterceptor> interceptors;
private int index;
public RealJPushInterceptor(List<JPushInterceptor> interceptors, int index){
this.interceptors = interceptors;
this.index = index;
}
public boolean intercept(String type, String extra){
if(index >= interceptors.size()){
return true;
}
JPushInterceptor jPushInterceptor = interceptors.get(index);
boolean hasProcess = jPushInterceptor.intercept(type, extra);
if(hasProcess){
return true;
}else{
RealJPushInterceptor realJPushInterceptor = new RealJPushInterceptor(interceptors, index + 1);
return realJPushInterceptor.intercept(type, extra);
}
}
}
3. 拦截器容器
public class JPushContainer {
private List<JPushInterceptor> interceptors = new ArrayList<>();
private JPushContainer(){}
private static JPushContainer instance = null;
public static JPushContainer getInstance(){
if(instance == null){
synchronized(JPushContainer.class){
if(instance == null){
instance = new JPushContainer();
}
}
}
return instance;
}
public void addInterceptor(JPushInterceptor interceptor){
getInterceptors().add(interceptor);
}
public List<JPushInterceptor> getInterceptors() {
return interceptors;
}
}
4. 实际开发需要的拦截器实例
public class ToastInterceptor implements JPushInterceptor {
@Override
public boolean intercept(String type, String extra) {
if("toast".equals(type)){
//处理toast
return true;
}
return false;
}
}
public class PopupInterceptor implements JPushInterceptor {
@Override
public boolean intercept(String type, String extra) {
if("popup".equals(type)){
//处理popup
return true;
}
return false;
}
}
5. 进入 Application 的时候注册
public void onCreate() {
super.onCreate();
JPushContainer.getInstance().addInterceptor(new ToastInterceptor());
JPushContainer.getInstance().addInterceptor(new PopupInterceptor());
}
