{"id":389,"date":"2023-02-25T08:44:45","date_gmt":"2023-02-25T00:44:45","guid":{"rendered":"https:\/\/www.appblog.cn\/?p=389"},"modified":"2023-04-30T14:38:04","modified_gmt":"2023-04-30T06:38:04","slug":"rxjava2-learning-1-observer-mode","status":"publish","type":"post","link":"https:\/\/www.appblog.cn\/index.php\/2023\/02\/25\/rxjava2-learning-1-observer-mode\/","title":{"rendered":"RxJava2\u5b66\u4e60\u4e4b\u4e00\uff1a\u89c2\u5bdf\u8005\u6a21\u5f0f"},"content":{"rendered":"<h2>\u4ec0\u4e48\u662f\u89c2\u5bdf\u8005\u6a21\u5f0f<\/h2>\n<p>\u89c2\u5bdf\u8005\uff08Observer\uff09\u6a21\u5f0f\uff1a\u662f\u5bf9\u8c61\u7684\u884c\u4e3a\u6a21\u5f0f\uff0c\u53c8\u53eb\u505a\u53d1\u5e03-\u8ba2\u9605\uff08Publish\/Subscribe\uff09\u6a21\u5f0f\u3001\u6a21\u578b-\u89c6\u56fe\uff08Model\/View\uff09\u6a21\u5f0f\u3001\u6e90-\u76d1\u542c\uff08Source\/Listener\uff09\u6a21\u5f0f\u6216\u8005\u4ece\u5c5e\uff08Dependents\uff09\u6a21\u5f0f\u3002<\/p>\n<p><!-- more --><\/p>\n<p>\u89c2\u5bdf\u8005\u6a21\u5f0f\u5b9a\u4e49\u4e86\u4e00\u79cd\u4e00\u5bf9\u591a\u7684\u4f9d\u8d56\u5173\u7cfb\uff0c\u8ba9\u591a\u4e2a\u89c2\u5bdf\u8005\u5bf9\u8c61\u540c\u65f6\u76d1\u542c\u67d0\u4e00\u4e2a\u4e3b\u9898\u5bf9\u8c61\uff0c\u8fd9\u4e2a\u4e3b\u9898\u5bf9\u8c61\u5728\u72b6\u6001\u4e0a\u53d1\u751f\u53d8\u5316\u65f6\uff0c\u4f1a\u901a\u77e5\u6240\u6709\u89c2\u5bdf\u8005\u5bf9\u8c61\uff0c\u4f7f\u5b83\u4eec\u80fd\u591f\u81ea\u52a8\u66f4\u65b0\u81ea\u5df1\u3002<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/www.yezhou.me\/AppBlog\/images\/Android\/\u89c2\u5bdf\u8005\u6a21\u5f0f.png\" alt=\"\u89c2\u5bdf\u8005\u6a21\u5f0f\" \/><\/p>\n<ul>\n<li>\u62bd\u8c61\u4e3b\u9898(Subject)\u89d2\u8272<\/li>\n<\/ul>\n<p>\u62bd\u8c61\u4e3b\u9898\u89d2\u8272\u628a\u6240\u6709\u5bf9\u89c2\u5bdf\u8005\u5bf9\u8c61\u7684\u5f15\u7528\u4fdd\u5b58\u5728\u4e00\u4e2a\u805a\u96c6\uff08\u6bd4\u5982ArrayList\u5bf9\u8c61\uff09\u91cc\uff0c\u6bcf\u4e2a\u4e3b\u9898\u90fd\u53ef\u4ee5\u6709\u4efb\u4f55\u6570\u91cf\u7684\u89c2\u5bdf\u8005\u3002\u62bd\u8c61\u4e3b\u9898\u63d0\u4f9b\u4e00\u4e2a\u63a5\u53e3\uff0c\u53ef\u4ee5\u589e\u52a0\u548c\u5220\u9664\u89c2\u5bdf\u8005\u5bf9\u8c61\uff0c\u62bd\u8c61\u4e3b\u9898\u89d2\u8272\u53c8\u53eb\u505a\u62bd\u8c61\u88ab\u89c2\u5bdf\u8005(Observable)\u89d2\u8272\u3002<\/p>\n<ul>\n<li>\u5177\u4f53\u4e3b\u9898(ConcreteSubject)\u89d2\u8272<\/li>\n<\/ul>\n<p>\u5c06\u6709\u5173\u72b6\u6001\u5b58\u5165\u5177\u4f53\u89c2\u5bdf\u8005\u5bf9\u8c61\uff1b\u5728\u5177\u4f53\u4e3b\u9898\u7684\u5185\u90e8\u72b6\u6001\u6539\u53d8\u65f6\uff0c\u7ed9\u6240\u6709\u767b\u8bb0\u8fc7\u7684\u89c2\u5bdf\u8005\u53d1\u51fa\u901a\u77e5\u3002\u5177\u4f53\u4e3b\u9898\u89d2\u8272\u53c8\u53eb\u505a\u5177\u4f53\u88ab\u89c2\u5bdf\u8005(Concrete Observable)\u89d2\u8272\u3002<\/p>\n<ul>\n<li>\u62bd\u8c61\u89c2\u5bdf\u8005(Observer)\u89d2\u8272<\/li>\n<\/ul>\n<p>\u4e3a\u6240\u6709\u7684\u5177\u4f53\u89c2\u5bdf\u8005\u5b9a\u4e49\u4e00\u4e2a\u63a5\u53e3\uff0c\u5728\u5f97\u5230\u4e3b\u9898\u7684\u901a\u77e5\u65f6\u66f4\u65b0\u81ea\u5df1\uff0c\u8fd9\u4e2a\u63a5\u53e3\u53eb\u505a\u66f4\u65b0\u63a5\u53e3\u3002<\/p>\n<ul>\n<li>\u5177\u4f53\u89c2\u5bdf\u8005(ConcreteObserver)\u89d2\u8272<\/li>\n<\/ul>\n<p>\u5b58\u50a8\u4e0e\u4e3b\u9898\u7684\u72b6\u6001\u81ea\u6070\u7684\u72b6\u6001\u3002\u5177\u4f53\u89c2\u5bdf\u8005\u89d2\u8272\u5b9e\u73b0\u62bd\u8c61\u89c2\u5bdf\u8005\u89d2\u8272\u6240\u8981\u6c42\u7684\u66f4\u65b0\u63a5\u53e3\uff0c\u4ee5\u4fbf\u4f7f\u672c\u8eab\u7684\u72b6\u6001\u4e0e\u4e3b\u9898\u7684\u72b6\u6001 \u50cf\u534f\u8c03\u3002\u5982\u679c\u9700\u8981\uff0c\u5177\u4f53\u89c2\u5bdf\u8005\u89d2\u8272\u53ef\u4ee5\u4fdd\u6301\u4e00\u4e2a\u6307\u5411\u5177\u4f53\u4e3b\u9898\u5bf9\u8c61\u7684\u5f15\u7528\u3002<\/p>\n<h2>\u89c2\u5bdf\u8005\u6a21\u5f0f\u5b9e\u8df5<\/h2>\n<ol>\n<li>Observable\uff1a\u88ab\u89c2\u5bdf\u8005\uff08\u4e3b\u9898Subject\uff09<\/li>\n<li>Observer\/Subscriber\uff1a\u89c2\u5bdf\u8005<\/li>\n<li>Subscribe\uff1a\u8ba2\u9605<\/li>\n<\/ol>\n<p>Observable \u548c Observer \u901a\u8fc7 subscribe() \u65b9\u6cd5\u5b9e\u73b0\u8ba2\u9605\u5173\u7cfb<\/p>\n<ul>\n<li>\u5b9a\u4e49\u89c2\u5bdf\u8005\u63a5\u53e3<\/li>\n<\/ul>\n<pre><code class=\"language-java\">public interface Observer {\n    String getName();\n    void update(String state);\n}<\/code><\/pre>\n<ul>\n<li>\u5b9a\u4e49\u76d1\u542c\u4e3b\u9898\u62bd\u8c61\u7c7b<\/li>\n<\/ul>\n<pre><code class=\"language-java\">public abstract class Subject {\n\n    \/\/\u4fdd\u5b58\u89c2\u5bdf\u8005\u96c6\u5408\n    private List&lt;Observer&gt; observers = new ArrayList&lt;Observer&gt;();\n\n    \/**\n     * \u6dfb\u52a0\u89c2\u5bdf\u8005\n     * @param observer\n     *\/\n    public void attach(Observer observer) {\n        observers.add(observer);\n        System.out.println(&quot;\u6dfb\u52a0\u89c2\u5bdf\u8005\uff1a&quot; + observer.getName());\n    }\n\n    public void dettch(Observer observer) {\n        observers.remove(observer);\n        System.out.println(&quot;\u79fb\u9664\u89c2\u5bdf\u8005\uff1a&quot; + observer.getName());\n    }\n\n    \/**\n     * \u901a\u77e5\u6240\u6709\u89c2\u5bdf\u8005\u66f4\u65b0\u72b6\u6001\n     * @param state\n     *\/\n    public void notifyObservers(String state) {\n        for (Observer observer : observers) {\n            observer.update(state);\n        }\n    }\n\n}<\/code><\/pre>\n<ul>\n<li>\u89c2\u5bdf\u8005\u6a21\u5f0f\u7684\u4e00\u4e2a\u5b9e\u73b0\uff1a\u5973\u670b\u53cb\u89c2\u5bdf\u8005<\/li>\n<\/ul>\n<pre><code class=\"language-java\">public class GFObserver implements Observer {\n\n    private String name;\n\n    public GFObserver(String name) {\n        this.name = name;\n    }\n\n    @Override\n    public String getName() {\n        return name;\n    }\n\n    @Override\n    public void update(String state) {\n        System.out.println(this.name + &quot; \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a&quot; + state);\n    }\n\n}<\/code><\/pre>\n<ul>\n<li>\u8ba2\u9605\u4e3b\u9898\u7684\u4e00\u4e2a\u5b9e\u73b0<\/li>\n<\/ul>\n<pre><code class=\"language-java\">public class MySubject extends Subject {\n\n    public void change(String state) {\n        notifyObservers(state);\n    }\n\n}<\/code><\/pre>\n<ul>\n<li>\u4e3b\u51fd\u6570\u6d4b\u8bd5<\/li>\n<\/ul>\n<pre><code class=\"language-java\">public class MainClient {\n\n    public static void main(String[] args) {\n        Observer observer1 = new GFObserver(&quot;\u5f20\u542b\u97f5&quot;);\n        Observer observer2 = new GFObserver(&quot;\u8303\u51b0\u51b0&quot;);\n        Observer observer3 = new GFObserver(&quot;\u6768\u9896&quot;);\n\n        MySubject subject = new MySubject();\n\n        subject.attach(observer1);\n        subject.attach(observer2);\n        subject.attach(observer3);\n\n        subject.change(&quot;\u6211\u5728\u5de5\u4f5c&quot;);\n        subject.change(&quot;\u6211\u5728\u5f00\u4f1a&quot;);\n\n        subject.dettch(observer3);\n        subject.change(&quot;\u6211\u5728\u5927\u4fdd\u5065&quot;);\n    }\n\n}<\/code><\/pre>\n<p>\u8fd0\u884c\u7ed3\u679c<\/p>\n<pre><code>\u6dfb\u52a0\u89c2\u5bdf\u8005\uff1a\u5f20\u542b\u97f5\n\u6dfb\u52a0\u89c2\u5bdf\u8005\uff1a\u8303\u51b0\u51b0\n\u6dfb\u52a0\u89c2\u5bdf\u8005\uff1a\u6768\u9896\n\u5f20\u542b\u97f5 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5de5\u4f5c\n\u8303\u51b0\u51b0 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5de5\u4f5c\n\u6768\u9896 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5de5\u4f5c\n\u5f20\u542b\u97f5 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5f00\u4f1a\n\u8303\u51b0\u51b0 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5f00\u4f1a\n\u6768\u9896 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5f00\u4f1a\n\u79fb\u9664\u89c2\u5bdf\u8005\uff1a\u6768\u9896\n\u5f20\u542b\u97f5 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5927\u4fdd\u5065\n\u8303\u51b0\u51b0 \u63a5\u6536\u5230\u65b0\u6d88\u606f\uff0c\u6700\u65b0\u72b6\u6001\uff1a\u6211\u5728\u5927\u4fdd\u5065<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u4ec0\u4e48\u662f\u89c2\u5bdf\u8005\u6a21\u5f0f \u89c2\u5bdf\u8005\uff08Observer\uff09\u6a21\u5f0f\uff1a\u662f\u5bf9\u8c61\u7684\u884c\u4e3a\u6a21\u5f0f\uff0c\u53c8\u53eb\u505a\u53d1\u5e03-\u8ba2\u9605\uff08Publish\/Subs [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[131],"tags":[132],"class_list":["post-389","post","type-post","status-publish","format-standard","hentry","category-rxjava","tag-rxjava"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/389","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/comments?post=389"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/389\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=389"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=389"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=389"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}