十次方微服务项目实战02--父工程及公共模块搭建

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一、搭建父工程

1.1 选择菜单file-new project ,弹出窗口中左侧菜单选择Maven ，点击next按钮

1.2 填写GroupId和ArtifacetId ,点击next按钮

1.3 点击Finish 完成

1.4 删除src文件夹

1.5 修改pom.xml 添加以下配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.tensquare</groupId><artifactId>tensquare_parent</artifactId><version>1.0-SNAPSHOT</version><packaging>pom</packaging><name>tensquare_parent</name><description>十次方项目-小洋人最happy</description><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.0.1.RELEASE</version><relativePath/></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies><repositories><repository><id>spring-snapshots</id><name>Spring Snapshots</name><url>https://repo.spring.io/snapshot</url><snapshots><enabled>true</enabled></snapshots></repository><repository><id>spring-milestones</id><name>Spring Milestones</name><url>https://repo.spring.io/milestone</url><snapshots><enabled>false</enabled></snapshots></repository></repositories><pluginRepositories><pluginRepository><id>spring-snapshots</id><name>Spring Snapshots</name><url>https://repo.spring.io/snapshot</url><snapshots><enabled>true</enabled></snapshots></pluginRepository><pluginRepository><id>spring-milestones</id><name>Spring Milestones</name><url>https://repo.spring.io/milestone</url><snapshots><enabled>false</enabled></snapshots></pluginRepository></pluginRepositories></project>

1.6 当IDEA右下角弹出提示 ,点击Enable Auto-Import 自动导入依赖

至此，父工程搭建完成。

二、搭建公共子模块tensquare_common

2.1 右键点击工程，弹出菜单选择New-Module 弹出窗口选择Maven ,点击next按钮

2.2 点击finish

2.3 创建返回结果实体类

2.3.1 新建entity包，包下创建类Result

该类用于控制器类返回结果。

代码如下：

package entity;/*** Created by me on 2019/6/25.*/
public class Result<T> {private boolean flag;private Integer code;private String message;private Object data;public Result(boolean flag, Integer code, String message, Object data) {this.flag = flag;this.code = code;this.message = message;this.data = data;}public Result(boolean flag, Integer code, String message) {this.flag = flag;this.code = code;this.message = message;}public Result() {}public boolean isFlag() {return flag;}public void setFlag(boolean flag) {this.flag = flag;}public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}public String getMessage() {return message;}public void setMessage(String message) {this.message = message;}public Object getData() {return data;}public void setData(Object data) {this.data = data;}
}

2.4 创建类PageResult

该类用于返回分页结果。

代码如下：

package entity;import java.util.List;/*** Created by me on 2019/6/25.*/
public class PageResult<T> {private long total;private List<T> rows;public PageResult(long total, List<T> rows) {this.total = total;this.rows = rows;}public long getTotal() {return total;}public void setTotal(long total) {this.total = total;}public List<T> getRows() {return rows;}public void setRows(List<T> rows) {this.rows = rows;}
}

2.5 创建返回码定义类

将错误码统一归类管理。

代码如下：

package entity;/*** Created by me on 2019/6/25.*/
public class StatusCode {public static final int OK = 20000;// 成功public static final int ERROR = 20001;// 失败public static final int LOGIN_ERROR = 20002;// 用户名或密码错误public static final int ACCESS_ERROR = 20003;// 权限不在不public static final int REMOTE_ERROR = 20004;// 远程调用失败public static final int REP_ERROR = 20005;// 重复操作
}

2.6 分布式ID生成器

由于我们的数据库在生产环境中要分片部署(MyCat),所以我们不能使用数据库本身的自增功能来产生主键值，只能由程序来生成唯一的主键值。

我们采用的是开源的 twitter的 snowflake (雪花)算法。

默认情况下41bit的时间戳可以支持该算法使用到2082年，10bit的工作机器id可以 支持1024台机器，序列号支持1毫秒产生4096个自增序列id .

SnowFlake的优点是，整体上按照时间自增排序，并且整个分布式系统内不会产生ID碰撞(由数据中心ID和机器ID 作区分)，并且效率较高。

经测试，SnowFlake每秒能够产生26万ID左右

在tensquare_common工程中创建util包，新建IdWorker.java文件(分布式ID生成器)，将如下代码拷入即可。

package util;import java.lang.management.ManagementFactory;
import java.net.InetAddress;
import java.net.NetworkInterface;/*** <p>名称：IdWorker.java</p>* <p>描述：分布式自增长ID</p>* <pre>*     Twitter的 Snowflake　JAVA实现方案* </pre>* 核心代码为其IdWorker这个类实现，其原理结构如下，我分别用一个0表示一位，用—分割开部分的作用：* 1||0---0000000000 0000000000 0000000000 0000000000 0 --- 00000 ---00000 ---000000000000* 在上面的字符串中，第一位为未使用（实际上也可作为long的符号位），接下来的41位为毫秒级时间，* 然后5位datacenter标识位，5位机器ID（并不算标识符，实际是为线程标识），* 然后12位该毫秒内的当前毫秒内的计数，加起来刚好64位，为一个Long型。* 这样的好处是，整体上按照时间自增排序，并且整个分布式系统内不会产生ID碰撞（由datacenter和机器ID作区分），* 并且效率较高，经测试，snowflake每秒能够产生26万ID左右，完全满足需要。* <p>* 64位ID (42(毫秒)+5(机器ID)+5(业务编码)+12(重复累加))** @author Polim*/
public class IdWorker {// 时间起始标记点，作为基准，一般取系统的最近时间（一旦确定不能变动）private final static long twepoch = 1288834974657L;// 机器标识位数private final static long workerIdBits = 5L;// 数据中心标识位数private final static long datacenterIdBits = 5L;// 机器ID最大值private final static long maxWorkerId = -1L ^ (-1L << workerIdBits);// 数据中心ID最大值private final static long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);// 毫秒内自增位private final static long sequenceBits = 12L;// 机器ID偏左移12位private final static long workerIdShift = sequenceBits;// 数据中心ID左移17位private final static long datacenterIdShift = sequenceBits + workerIdBits;// 时间毫秒左移22位private final static long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;private final static long sequenceMask = -1L ^ (-1L << sequenceBits);/* 上次生产id时间戳 */private static long lastTimestamp = -1L;// 0，并发控制private long sequence = 0L;private final long workerId;// 数据标识id部分private final long datacenterId;public IdWorker(){this.datacenterId = getDatacenterId(maxDatacenterId);this.workerId = getMaxWorkerId(datacenterId, maxWorkerId);}/*** @param workerId*            工作机器ID* @param datacenterId*            序列号*/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;}/*** 获取下一个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) {// 当前毫秒内，则+1sequence = (sequence + 1) & sequenceMask;if (sequence == 0) {// 当前毫秒内计数满了，则等待下一秒timestamp = tilNextMillis(lastTimestamp);}} else {sequence = 0L;}lastTimestamp = timestamp;// ID偏移组合生成最终的ID，并返回IDlong 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>* 获取 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 获取16个低位*/return (mpid.toString().hashCode() & 0xffff) % (maxWorkerId + 1);}/*** <p>* 数据标识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;}}

至此，公共模块common搭建完毕。

三、小结

通过该篇文章，主要学会了：

• 搭建父工程
• 搭建公共模块，创建通用返回类
• 分布式ID生成器(snowflake算法)

这篇关于十次方微服务项目实战02--父工程及公共模块搭建的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

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