一、目标
增加filterchain功能
二、代码
1.Filter.java
public interface Filter {
public String doFilter(String str);
}2.FilterChain.java
import java.util.ArrayList;
import java.util.List; public class FilterChain implements Filter { private List<Filter> filters = new ArrayList<Filter>(); public String doFilter(String str) {
for(Filter f : filters){
str = f.doFilter(str);
}
return str;
} //把函数的返回值设为FilterChain，返回this,就能方便链式编写代码
public FilterChain addFilter(Filter filter) {
filters.add(filter);
return this;
} }
3.HTMLFilter.java
public class HTMLFilter implements Filter {
@Override
public String doFilter(String str) {
return str.replace('<', '[').replace(">", "]");
}
}4.SensitiveFilter.java
public class SensitiveFilter implements Filter {
@Override
public String doFilter(String str) {
return str.replace("敏感", "幸福");
}
}5.MsgProcessor.java
public class MsgProcessor {
//private List<Filter> filters = new ArrayList<Filter>();
FilterChain filterChain;
private String msg;
public FilterChain getFilterChain() {
return filterChain;
}
public void setFilterChain(FilterChain filterChain) {
this.filterChain = filterChain;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
public String process() {
return filterChain.doFilter(msg);
}
}6.Test.java
public class Test {
@org.junit.Test
public void testFilter(){
MsgProcessor processor = new MsgProcessor();
String msg = "<html>敏感字眼</html>";
processor.setMsg(msg);
FilterChain fc1 = new FilterChain();
fc1.addFilter(new HTMLFilter());
FilterChain fc2 = new FilterChain();
fc2.addFilter(new SensitiveFilter());
//由于FilterChain实现了Filter接口，所以FilterChain同时也是Filter,所以可以调用addFilter增加fc2
fc1.addFilter(fc2);
processor.setFilterChain(fc1);
String result = processor.process();
System.out.println(result);
}
}三、运行结果