test.java

import java.util.List;

public class TestClass {
  public void ProcessInfo(List<InfoBase> infoList) {
     StringBuilder result = new StringBuilder();
    
     for (int i = 0; i < infoList.size(); i++) {
        InfoBase info = infoList.get(i);
        if (this.Validate(info)) {
           StringBuilder infoData = this.ExtractData(info);
           result.append(infoData);
        } else {
           infoList.remove(info);
        }
     }
    
     System.out.println(result.toString());
   }
 
   private <T extends InfoBase> boolean Validate(T infoBase) {
     boolean isValid = false;
    
     switch (infoBase.GetInfoType()) {
        case Sport: {
           if (infoBase instanceof InfoSport) {
              if (((InfoSport) infoBase).title.startsWith("Sport news: ")) {
                 isValid = true;
              }
            }
          }
          break;
        case Music: {
            if (infoBase instanceof InfoMusic) {
              if (((InfoMusic) infoBase).title.startsWith("Music charts: ")) {
                 isValid = true;
              }
           }
        }
        break;
     }
    
     return infoBase != null && isValid;
  }
 
  private StringBuilder ExtractData(InfoBase info) {
     StringBuilder result = new StringBuilder();
     String title = info.GetInfoType().getTitle();
    
     result.append(title).append("\r\n");
     result.append(info.getData()).append("\r\n\r\n");
    
     return result;
  }
 
  private abstract class InfoBase {
     protected InfoType infoType;
    
     public InfoType GetInfoType() {
        return this.infoType;
     }
    
     public abstract String getData();
  }
 
  public class InfoMusic extends InfoBase {
     public String title;
     public String author;
    
     public InfoMusic(String title, String author) {
        this.infoType = InfoType.Music;
        this.title = title;
        this.author = author;
     }
    
     public String getData() {
        return String.format("%s\r\nAuthor:%s", this.title, this.author);
     }
   }
 
   public class InfoSport extends InfoBase {
     public String title;
     public String data;
    
     public InfoSport(String title, String data) {
        this.infoType = InfoType.Sport;
        this.title = title;
        this.data = data;
     }
    
     public String getData() {
        return String.format("%s\r\n%s", this.title, this.data);
     }
  }
 
  private enum InfoType {
     Music,
     Sport,
     ;
    
     private String getTitle() {
        switch (this) {
           case Sport:
              return "<b>Breaking sport news!</b>";
           case Music:
              return "<b>New single!</b>";
        }
       
        return "";
     }
  }
}