Feeds system Result List based cursor theory

gistfile1.java

/** 
 * Result List based cursor theory 
 *  
 * @author vongosling 
 * @param <T> 
 */  
public class ResultCursorList<T> extends BaseDo {  
  
    private static final long serialVersionUID = -6593448580923210640L;  
    /** 
     * Result list 
     */  
    private List<T>           values;  
    /** 
     * Total result 
     */  
    private Long              totalCount;  
    /** 
     * For forwarding query,it can be timestamp or offset,when 
     * timestamp,previousCursor must be less than or equals nextCursor 
     */  
    private Long              previousCursor;  
    /** 
     * For backwarding query 
     */  
    private Long              nextCursor;  
  
    /** 
     * Init case 
     *  
     * @param clasz 
     * @return 
     */  
    public static <T> ResultCursorList<T> build(Class<T> clazz) {  
        return new ResultCursorList<T>().setValues(new ArrayList<T>()).setTotalCount(0l)  
                .setPreviousCursor(0l).setNextCursor(0l);  
    }  
  
    /** 
     * Common case 
     *  
     * @param clasz 
     * @param values 
     * @param totalCount 
     * @param previousCursor 
     * @param nextCursor 
     * @return 
     */  
    public static <T> ResultCursorList<T> build(Class<T> clazz, List<T> values, Long totalCount,  
                                                Long previousCursor, Long nextCursor) {  
        if (values == null || values.isEmpty()) {  
            return build(clazz);  
        }  
        return new ResultCursorList<T>().setValues(values).setTotalCount(totalCount)  
                .setPreviousCursor(previousCursor).setNextCursor(nextCursor);  
    }  
  
    public List<T> getValues() {  
        return values;  
    }  
  
    public ResultCursorList<T> setValues(List<T> values) {  
        this.values = values;  
        return this;  
    }  
  
    public Long getTotalCount() {  
        return totalCount;  
    }  
  
    public ResultCursorList<T> setTotalCount(Long totalCount) {  
        this.totalCount = totalCount;  
        return this;  
    }  
  
    public Long getPreviousCursor() {  
        return previousCursor;  
    }  
  
    public ResultCursorList<T> setPreviousCursor(Long previousCursor) {  
        this.previousCursor = previousCursor;  
        return this;  
    }  
  
    public Long getNextCursor() {  
        return nextCursor;  
    }  
  
    public ResultCursorList<T> setNextCursor(Long nextCursor) {  
        this.nextCursor = nextCursor;  
        return this;  
    }  
}