Java 结果集封装

1.返回消息及状态码

/**
 * 
Title: ReturnMsg.java<／p>
 * 
Description: 返回結果的状态碼和信息<／p>
 * @author shy
 * @Version 1.0
 * @Date 2018年7月3日上午10:35:05
 */
public enum ReturnMsg {

	SUCCESS("0", "成功"),
	EXCEPTION1("10001", "1*******异常"),
	EXCEPTION2("10002", "2*******异常"),
	EXCEPTION3("10003", "3*******异常"),
	EXCEPTION4("10004", "4*******异常"),
	EXCEPTION5("10005", "5*******异常"),
	ERROR("-1", "失败");
	
	private String code;
	private String msg;
	
	private ReturnMsg (String code, String msg) {
		this.code = code;
		this.msg = msg;
	}
	
	public String getCode() {
		return code;
	}
	public void setCode(String code) {
		this.code = code;
	}
	public String getMsg() {
		return msg;
	}
	public void setMsg(String msg) {
		this.msg = msg;
	}
}

2.封装结果集

/**
 * 
Title: ReturnResult.java<／p>
 * 
Description: 返回封裝結果集<／p>
 * @author shy
 * @Version 1.0
 * @Date 2018年7月3日上午10:36:40
 */
public class ReturnResult {

	private long total;
	private Object data;
	private String code;
	private String msg;

	private ReturnResult(long total, Object data, String code, String msg) {
		this.total = total;
		this.data = data;
		this.code = code;
		this.msg = msg;
	}

	private ReturnResult(Object data) {
		this.data = data;
		this.code = ReturnMsg.SUCCESS.getCode();
		this.msg = ReturnMsg.SUCCESS.getMsg();
	}

	private ReturnResult(long total, Object data) {
		this.total = total;
		this.data = data;
		this.code = ReturnMsg.SUCCESS.getCode();
		this.msg = ReturnMsg.SUCCESS.getMsg();
	}

	private ReturnResult(String code, String msg) {
		this.code = code;
		this.msg = msg;
	}

	private ReturnResult() {
		this.code = ReturnMsg.ERROR.getCode();
		this.msg = ReturnMsg.ERROR.getMsg();
	}

	/***
	 * 输入参数:
	 * 
	 * @param total
	 * @param data
	 * @param code
	 * @param msg
	 * @return 返回成功，包含total、code、msg、data
	 */
	public static ReturnResult success(long total, Object data, String code, String msg) {
		return new ReturnResult(total, data, code, msg);
	}

	/***
	 * 输入参数
	 * 
	 * @param total
	 * @param data
	 * @return 返回成功，包含total、code、msg、data
	 */
	public static ReturnResult success(long total, Object data) {
		return new ReturnResult(total, data);
	}

	/***
	 * 输入参数：
	 * 
	 * @param data
	 * @return 返回成功，包含code、msg、data
	 */
	public static ReturnResult success(Object data) {
		return new ReturnResult(data);
	}

	/***
	 * 无输入参数 返回成功，包含code、msg
	 * 
	 * @return
	 */
	public static ReturnResult success() {
		return new ReturnResult("");
	}

	/***
	 * 无输入参数 返回失败，包含code、msg
	 * 
	 * @return
	 */
	public static ReturnResult error() {
		return new ReturnResult();
	}

	public static ReturnResult error(String code, String msg) {
		return new ReturnResult(code, msg);
	}

	public long getTotal() {
		return total;
	}

	public void setTotal(long total) {
		this.total = total;
	}

	public Object getData() {
		return data;
	}

	public void setData(Object data) {
		this.data = data;
	}

	public String getCode() {
		return code;
	}

	public void setCode(String code) {
		this.code = code;
	}

	public String getMsg() {
		return msg;
	}

	public void setMsg(String msg) {
		this.msg = msg;
	}
}

3.代码使用

@RequestMapping(value = "/list")
@ResponseBody
public ReturnResult getEmpList() throws IOException {
	String name = "admin_1";
	PageHelper.startPage(2, 2);
	PageHelper.orderBy("age");
	List empList = null;
	long total = -1;
	try {
		empList = empService.queryEmpList(name);
		if (null == empList || empList.isEmpty()) {
			return ReturnResult.error(ReturnMsg.EXCEPTION2.getCode(), ReturnMsg.EXCEPTION2.getMsg());
		}
		PageInfo pageEmp = new PageInfo(empList);
		total = pageEmp.getTotal();
		empList = pageEmp.getList();
		System.out.println(total);
	} catch (Exception e) {
		ReturnResult.error(ReturnMsg.EXCEPTION1.getCode(), ReturnMsg.EXCEPTION1.getMsg());
	}
	return ReturnResult.success(total, empList);
}

4.输出

total	4
data	
    0	
        empno	2
        empname	"admin_1"
        age	33
        sex	2
        indate	1529596800000
        deptno	30
    1	
        empno	4
        empname	"admin_4"
        age	44
        sex	2
        indate	1529856000000
        deptno	10
code	"0"
msg	"成功"