此模塊依然基于以上博客書寫先慷。
封裝統(tǒng)一返回數(shù)據(jù)格式
在 blog_common 模塊中主要放置一些公共使用功能饮笛，創(chuàng)建entity 包，用于存放 統(tǒng)一返回數(shù)據(jù)格式類论熙。
注：此項(xiàng)目使用的lombok 工具福青。
- 新建 Result 類，主要定義返 回字段和統(tǒng)一返回方法,實(shí)現(xiàn)代碼如下：
package com.dongl.entity;
import lombok.Data;
/**
* @Description: 數(shù)據(jù)統(tǒng)一返回格式化
* @author: YaoGuangX
* @date: 2020/3/13 21:24
* @Version: 1.0
*/
@Data
public class Result {
private boolean flag;
private Integer code;
private String message;
private Object data;
public Result() {
}
public Result(boolean flag, Integer code, String message) {
this.flag = flag;
this.code = code;
this.message = message;
}
public Result(boolean flag, Integer code, String message, Object data) {
this.flag = flag;
this.code = code;
this.message = message;
this.data = data;
}
public static Result success() {
return new Result(true, ResultEnum.SUCCESS.getCode(), ResultEnum.SUCCESS.getMsg());
}
public static Result success(String msg) {
return new Result(true, ResultEnum.SUCCESS.getCode(), msg);
}
public static Result success(Object data) {
return new Result(true, ResultEnum.SUCCESS.getCode(),ResultEnum.SUCCESS.getMsg(), data);
}
public static Result success(String msg, Object data) {
return new Result(true, ResultEnum.ERROR.getCode(), msg, data);
}
public static Result error() {
return new Result(true, ResultEnum.ERROR.getCode(), ResultEnum.ERROR.getMsg());
}
public static Result error(String msg) {
return new Result(true, ResultEnum.ERROR.getCode(), msg);
}
public static Result error(Object data) {
return new Result(true, ResultEnum.ERROR.getCode(),ResultEnum.ERROR.getMsg(), data);
}
public static Result error(String msg, Object data) {
return new Result(true, ResultEnum.ERROR.getCode(), msg, data);
}
}
- 在ResultEnum 枚舉類中主要定義 狀態(tài)碼及返回消息脓诡，代碼實(shí)現(xiàn)如下：
package com.dongl.entity;
public enum ResultEnum {
SUCCESS(20000, "成功"),
ERROR(20001, "失敗"),
LOGIN_ERROR(20002, "用戶名密碼錯誤"),
ACCESS_ERROR(20003, "權(quán)限不足"),
REMOTE_ERROR(20004, "遠(yuǎn)程調(diào)用失敗"),
REP_ERROR(20005, "重復(fù)操作");
private Integer code;
private String msg;
ResultEnum(Integer code, String msg) {
this.code = code;
this.msg = msg;
}
public Integer getCode() {
return code;
}
public String getMsg() {
return msg;
}
}
- PageResult 類中主要定義分頁數(shù)據(jù)返回格式无午，實(shí)現(xiàn)代碼如下：
package com.dongl.entity;
import lombok.Data;
import java.util.List;
/**
* @Description: 封裝分頁返回數(shù)據(jù)類型
* @author: YaoGuangX
* @date: 2020/3/13 22:21
* @Version: 1.0
*/
@Data
public class PageResult<T> {
private long total;
private List<T> rows;
public PageResult() {
}
public PageResult(long total, List<T> rows) {
this.total = total;
this.rows = rows;
}
}
- 定義工具類 IdWorker。
通過 雪花算法獲取 分布式自增長 id 祝谚，代碼實(shí)現(xiàn)如下：
package com.dongl.utils;
import java.lang.management.ManagementFactory;
import java.net.InetAddress;
import java.net.NetworkInterface;
/**
* <p>名稱：IdWorker.java</p>
* <p>描述：分布式自增長ID</p>
* <pre>
* Twitter的 Snowflake JAVA實(shí)現(xiàn)方案
* </pre>
* 核心代碼為其IdWorker這個類實(shí)現(xiàn)宪迟，其原理結(jié)構(gòu)如下，我分別用一個0表示一位交惯，用—分割開部分的作用：
* 1||0---0000000000 0000000000 0000000000 0000000000 0 --- 00000 ---00000 ---000000000000
* 在上面的字符串中次泽，第一位為未使用（實(shí)際上也可作為long的符號位），接下來的41位為毫秒級時間席爽，
* 然后5位datacenter標(biāo)識位意荤，5位機(jī)器ID（并不算標(biāo)識符，實(shí)際是為線程標(biāo)識）只锻，
* 然后12位該毫秒內(nèi)的當(dāng)前毫秒內(nèi)的計數(shù)玖像，加起來剛好64位，為一個Long型炬藤。
* 這樣的好處是御铃，整體上按照時間自增排序，并且整個分布式系統(tǒng)內(nèi)不會產(chǎn)生ID碰撞（由datacenter和機(jī)器ID作區(qū)分）沈矿，
* 并且效率較高上真，經(jīng)測試，snowflake每秒能夠產(chǎn)生26萬ID左右羹膳，完全滿足需要睡互。
* <p>
* 64位ID (42(毫秒)+5(機(jī)器ID)+5(業(yè)務(wù)編碼)+12(重復(fù)累加))
*
* @author Polim
*/
public class IdWorker {
// 時間起始標(biāo)記點(diǎn)，作為基準(zhǔn)，一般取系統(tǒng)的最近時間（一旦確定不能變動）
private final static long twepoch = 1288834974657L;
// 機(jī)器標(biāo)識位數(shù)
private final static long workerIdBits = 5L;
// 數(shù)據(jù)中心標(biāo)識位數(shù)
private final static long datacenterIdBits = 5L;
// 機(jī)器ID最大值
private final static long maxWorkerId = -1L ^ (-1L << workerIdBits);
// 數(shù)據(jù)中心ID最大值
private final static long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
// 毫秒內(nèi)自增位
private final static long sequenceBits = 12L;
// 機(jī)器ID偏左移12位
private final static long workerIdShift = sequenceBits;
// 數(shù)據(jù)中心ID左移17位
private final static long datacenterIdShift = sequenceBits + workerIdBits;
// 時間毫秒左移22位
private final static long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
private final static long sequenceMask = -1L ^ (-1L << sequenceBits);
/* 上次生產(chǎn)id時間戳 */
private static long lastTimestamp = -1L;
// 0就珠，并發(fā)控制
private long sequence = 0L;
private final long workerId;
// 數(shù)據(jù)標(biāo)識id部分
private final long datacenterId;
public IdWorker(){
this.datacenterId = getDatacenterId(maxDatacenterId);
this.workerId = getMaxWorkerId(datacenterId, maxWorkerId);
}
/**
* @param workerId
* 工作機(jī)器ID
* @param datacenterId
* 序列號
*/
public IdWorker(long workerId, long datacenterId) {
if (workerId > maxWorkerId || workerId < 0) {
throw new IllegalArgumentException(String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
}
if (datacenterId > maxDatacenterId || datacenterId < 0) {
throw new IllegalArgumentException(String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
}
this.workerId = workerId;
this.datacenterId = datacenterId;
}
/**
* 獲取下一個ID
*
* @return
*/
public synchronized long nextId() {
long timestamp = timeGen();
if (timestamp < lastTimestamp) {
throw new RuntimeException(String.format("Clock moved backwards. Refusing to generate id for %d milliseconds", lastTimestamp - timestamp));
}
if (lastTimestamp == timestamp) {
// 當(dāng)前毫秒內(nèi)寇壳，則+1
sequence = (sequence + 1) & sequenceMask;
if (sequence == 0) {
// 當(dāng)前毫秒內(nèi)計數(shù)滿了，則等待下一秒
timestamp = tilNextMillis(lastTimestamp);
}
} else {
sequence = 0L;
}
lastTimestamp = timestamp;
// ID偏移組合生成最終的ID妻怎，并返回ID
long nextId = ((timestamp - twepoch) << timestampLeftShift)
| (datacenterId << datacenterIdShift)
| (workerId << workerIdShift) | sequence;
return nextId;
}
private long tilNextMillis(final long lastTimestamp) {
long timestamp = this.timeGen();
while (timestamp <= lastTimestamp) {
timestamp = this.timeGen();
}
return timestamp;
}
private long timeGen() {
return System.currentTimeMillis();
}
/**
* <p>
* 獲取 maxWorkerId
* </p>
*/
protected static long getMaxWorkerId(long datacenterId, long maxWorkerId) {
StringBuffer mpid = new StringBuffer();
mpid.append(datacenterId);
String name = ManagementFactory.getRuntimeMXBean().getName();
if (!name.isEmpty()) {
/*
* GET jvmPid
*/
mpid.append(name.split("@")[0]);
}
/*
* MAC + PID 的 hashcode 獲取16個低位
*/
return (mpid.toString().hashCode() & 0xffff) % (maxWorkerId + 1);
}
/**
* <p>
* 數(shù)據(jù)標(biāo)識id部分
* </p>
*/
protected static long getDatacenterId(long maxDatacenterId) {
long id = 0L;
try {
InetAddress ip = InetAddress.getLocalHost();
NetworkInterface network = NetworkInterface.getByInetAddress(ip);
if (network == null) {
id = 1L;
} else {
byte[] mac = network.getHardwareAddress();
id = ((0x000000FF & (long) mac[mac.length - 1])
| (0x0000FF00 & (((long) mac[mac.length - 2]) << 8))) >> 6;
id = id % (maxDatacenterId + 1);
}
} catch (Exception e) {
System.out.println(" getDatacenterId: " + e.getMessage());
}
return id;
}
}
