链式设计模式

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

public class FaceFilter implements Filter {

    @Override
    public String doFilter(String str) {
        String r = str.replace(":)", "^V^");
        return r;
    }

}

public class HTMLFilter implements Filter {

    public String doFilter(String str) {
        String  r = str.replace('<', '[')
                       .replace('>', ']');
        return r;
    }
}

public class SesitiveFilter implements Filter {

    @Override
    public String doFilter(String str) {

        String r = str.replace("被就业", "就业")
                      .replace("敏感", "mingan");
        return r;
    }

}

import java.util.ArrayList;
import java.util.List;

public class FilterChain implements Filter{

    List<Filter> filters = new ArrayList<Filter>();
    
    public FilterChain addFilter(Filter filter){
        this.filters.add(filter);
        return this;
    }
    
    public String doFilter(String str){
        String r = str;
        for(Filter f : filters){
            r = f.doFilter(r);
            System.out.println(f);
        }
        return r;
    }
}
 
public class MsgProcessor {
    private String msg;
    FilterChain fc;

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public FilterChain getFc() {
        return fc;
    }

    public void setFc(FilterChain fc) {
        this.fc = fc;
    }
    
    public String process(){
        return fc.doFilter(msg);
    }
} 

public class Main {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String msg = "大家好:)，<script>,敏感，被就业，网络授课没有感觉,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);
        
    }
}