10、groovy grails List 集合 排序方法1

class Contract implements Comparable<Contract>{
    int id //合同id
    UserInformation userInfo //用户扩展表
    double bond = 0.0 //保证金
    UserLevel userLevel //用户级别
    Date signDate //签订日期
    Date beginDate //合同开始时间
    Date endDate //合同结束时间
    String openAccount //开户行
    String accountName //开户名
    String accountNumber //开户账号
    String attachment   //合同附件
    int status = 1 //状态 1.执行中 2.已过期 3.未开始
    Date createDate //入库时间

    static constraints = {
        userInfo blank:true,nullable: true;
        bond blank:true,nullable: true;
        userLevel blank:true,nullable: true;
        signDate blank:true,nullable: true;
        openAccount blank:true,nullable: true;
        accountNumber blank:true,nullable: true;
        status blank:true,nullable: true;
        beginDate blank:true,nullable: true;
        endDate blank:true,nullable: true;
        attachment blank: true,nullable: true;
        createDate blank:true,nullable: true;
        accountName blank:true,nullable: true;
    }

    static mapping = {
        version false
    }
    //签订日期排序
    @Override
    int compareTo(Contract contract) {
        if (contract?.signDate==null){
            contract?.signDate = new Date(0)
        }
        if (!this.signDate) {
            this.signDate = new Date(0);
        }
        return contract?.signDate?.compareTo(signDate);
    }
}

class ContractController {

    def index() {
        def contractGroup = Contract.list();
        Collections.sort(contractGroup);
         render(view: "index",mapping:"adminurl",model：[contractGroup:contractGroup]);
    }
}