学习笔记--责任链

类似过滤器，可以自由增加过滤器个数，顺序

 

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模拟代码

Filter.java        接口让自定义的过滤器继承它

package filter; public interface Filter { String doFilter(String str); }  

 

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FaceFilter.java         继承Filter 实现功能

package filter; public class FaceFilter implements Filter { @Override public String doFilter(String str) { return str.replace(":)", "^V^"); } }  

 

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HTMLFilter.java 继承Filter 实现功能

package filter; public class HTMLFilter implements Filter { @Override public String doFilter(String str) { //process the html tag <> String r = str.replace('<', '[') .replace('>', ']'); return r; } }  

 

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SesitiveFilter.java 继承Filter 实现功能

package filter; public class SesitiveFilter implements Filter { @Override public String doFilter(String str) { //process the sensitive words String r = str.replace("被就业", "就业") .replace("敏感", ""); return r; } }  

 

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MsgProcessor.java process()方法实现过滤器链条的方法。返回类型是String

package filter; public class MsgProcessor { private String msg; //Filter[] filters = {new HTMLFilter(), new SesitiveFilter(), new FaceFilter()}; FilterChain fc; public FilterChain getFc() { return fc; } public void setFc(FilterChain fc) { this.fc = fc; } public String getMsg() { return msg; } public void setMsg(String msg) { this.msg = msg; } public String process() { return fc.doFilter(msg); } }  。

 

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FilterChain.java addFilter（）方法增加过滤器，返回类型是FilterChain 自身类型以便不断增加（小技巧，不这么用也可以在测试类Main中可以看到原因和效果）

package filter; import java.util.ArrayList; import java.util.List; public class FilterChain implements Filter { List<Filter> filters = new ArrayList<Filter>(); public FilterChain addFilter(Filter f) { this.filters.add(f); return this; } public String doFilter(String str) { String r = str; for(Filter f: filters) { r = f.doFilter(r); } return r; } }  

 

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main.java fc.addFilter(new HTMLFilter()) .addFilter(new SesitiveFilter())；（这就是小技巧）

package filter; public class Main { /** * @param args */ public static void main(String[] args) { String msg = "大家好:)，<script>，敏感，被就业，网络授课没感觉，因为看不见大家伙儿"; MsgProcessor mp = new MsgProcessor(); mp.setMsg(msg); FilterChain fc = new FilterChain(); fc.addFilter(new HTMLFilter()) .addFilter(new SesitiveFilter()) ; FilterChain fc2 = new FilterChain(); fc2.addFilter(new FaceFilter()); fc.addFilter(fc2); mp.setFc(fc); String result = mp.process(); System.out.println(result); } }  

 

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测试结果显示：大家好^V^，[script]，，就业，网络授课没感觉，因为看不见大家伙儿