求java 组合查询的思路

我想做个组合查询，界面有好多文本框，输入值后点击“查询”，最好有具体的代码？谢谢各位了？

我用的是JPA。。。。

/**
 * 根据Http服务注册ID和“入参”或“出参”标识，获取Http服务操作(参数)列表
 * @param httpsrvregid
 * @param inOrOut
 * @return List<P_IRE_HttpSrvOpReg>
 */
@Override
public List<P_IRE_HttpSrvOpReg> getHttpSrvOpByHttpSrvRegId(
        String httpsrvregid, String inOrOut, String operationTypeId) {
    if (em == null) {
        init();
    }
    Query query = em
            .createQuery("SELECT x FROM P_IRE_HttpSrvOpReg x WHERE"
                    + " x.httpsrvreg.httpsrvregid = :httpsrvregid and  x.paramcatalog = :paramcatalog and x.operationtype.operationtypeid = :operationtypeid and dr=0 ");
    query.setParameter("httpsrvregid", httpsrvregid);
    query.setParameter("paramcatalog", inOrOut);
    query.setParameter("operationtypeid", operationTypeId);
    @SuppressWarnings("unchecked")
    List<P_IRE_HttpSrvOpReg> listobj = query.getResultList();
    return listobj;
}