Guava动态调用方法

前言

大家在Coding的时候，经常会遇到这样一个情况，根据不同的条件去执行对应的代码。我们通常的处理方式是利用if-else判断，或者直接switch-case,特别是jdk1.6之后，swith开始支持判断String类型了。

但是如果有几十种情况上百种情况，用if-else来处理这段逻辑，代码看着特别不舒服。

解决这个麻烦有好几种办法，比如自定义注解、Spring结合策略模式、反射或者枚举。

下面分享一下使用Guava工具类通过反射动态调用方法。

业务描述

插座统计：数据库每添加一个插座实例，都统计一下这个插座属于中国哪个省份（细节不重要）

pom.xml

添加工具依赖

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>20.0</version>
</dependency>

ProvinceEnum.java

前端传过来的是中文，需要获取对应的英文名，然后通过拼接的方式生成方法名。

public enum ProvinceEnum {

    SHANDONG("山东", "Shandong"),

    SHANGHAI("上海", "Shanghai"),

    ZHEJIANG("浙江", "Zhejiang"),

    ANHUI("安徽", "Anhui"),

    FUJIAN("福建", "Fujian"),

    JIANGXI("江西", "Jiangxi"),

    GUANGDONG("广东", "Guangdong"),

    GUANGXI("广西", "Guangxi"),

    HAINAN("海南", "Hainan"),

    HENAN("河南", "Henan"),

    HUNAN("湖南", "Hunan"),

    HUBEI("湖北", "Hubei"),

    BEIJING("北京", "Beijing"),

    TIANJIN("天津", "Tianjin"),

    HEBEI("河北", "Hebei"),

    SHANXI("山西", "Shanxi"),

    INNERMONGOLIA("内蒙古", "Innermongolia"),

    NINGXIA("宁夏", "Ningxia"),

    QINGHAI("青海", "Qinghai"),

    SHAANXI("陕西", "Shaanxi"),

    GANSU("甘肃", "Gansu"),

    SINKIANG("新疆", "Sinkiang"),

    SICHUAN("四川", "Sichuan"),

    GUIZHOU("贵州", "Guizhou"),

    YUNNAN("云南", "Yunnan"),

    CHONGQING("重庆", "Chongqing"),

    TIBET("西藏", "Tibet"),

    LIAONING("辽宁", "Liaoning"),

    JILIN("吉林", "Jilin"),

    HEILONGJIANG("黑龙江", "Heilongjiang"),

    HONGKONG("香港", "Hongkong"),

    MACAO("澳门", "Macao"),

    TAIWAN("台湾", "Taiwan"),

    JIANGSU("江苏", "Jiangsu");

    private String code;

    private String msg;

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

    public String getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }

    public static String getMsgByCode(String code) {
        String msg = null;
        for (ProvinceEnum e : ProvinceEnum.values()) {
            if (e.getCode().equals(code)) {
                msg = e.getMsg();
                break;
            }
        }
        return msg;
    }

}

 

SocketStatistics.java

实体类，统计的对象

public class SocketStatistics {
    /**
     * 主键自增长
     */
    private Long pid;

    private Integer shandong;

    private Integer jiangsu;

    private Integer shanghai;

    private Integer zhejiang;

    private Integer anhui;

    private Integer fujian;

    private Integer jiangxi;

    private Integer guangdong;

    private Integer guangxi;

    private Integer hainan;

    private Integer henan;

    private Integer hunan;

    private Integer hubei;

    private Integer beijing;

    private Integer tianjin;

    private Integer hebei;

    private Integer shanxi;

    /**
     * 内蒙古
     */
    private Integer innermongolia;

    private Integer ningxia;

    private Integer qinghai;

    /**
     * 陕西
     */
    private Integer shaanxi;

    private Integer gansu;

    private Integer sinkiang;

    private Integer sichuan;

    private Integer guizhou;

    private Integer yunnan;

    private Integer chongqing;

    /**
     * 西藏
     */
    private Integer tibet;

    private Integer liaoning;

    private Integer jilin;

    private Integer heilongjiang;

    private Integer hongkong;

    /**
     * 澳门
     */
    private Integer macao;

    private Integer taiwan;

    /**
     * 在线数量
     */
    private Integer online;

    /**
     * 离线数量
     */
    private Integer outline;

    public Long getPid() {
        return pid;
    }

    public void setPid(Long pid) {
        this.pid = pid;
    }

    public Integer getShandong() {
        return shandong;
    }

    public void setShandong(Integer shandong) {
        this.shandong = shandong;
    }

    public Integer getJiangsu() {
        return jiangsu;
    }

    public void setJiangsu(Integer jiangsu) {
        this.jiangsu = jiangsu;
    }

    public Integer getShanghai() {
        return shanghai;
    }

    public void setShanghai(Integer shanghai) {
        this.shanghai = shanghai;
    }

    public Integer getZhejiang() {
        return zhejiang;
    }

    public void setZhejiang(Integer zhejiang) {
        this.zhejiang = zhejiang;
    }

    public Integer getAnhui() {
        return anhui;
    }

    public void setAnhui(Integer anhui) {
        this.anhui = anhui;
    }

    public Integer getFujian() {
        return fujian;
    }

    public void setFujian(Integer fujian) {
        this.fujian = fujian;
    }

    public Integer getJiangxi() {
        return jiangxi;
    }

    public void setJiangxi(Integer jiangxi) {
        this.jiangxi = jiangxi;
    }

    public Integer getGuangdong() {
        return guangdong;
    }

    public void setGuangdong(Integer guangdong) {
        this.guangdong = guangdong;
    }

    public Integer getGuangxi() {
        return guangxi;
    }

    public void setGuangxi(Integer guangxi) {
        this.guangxi = guangxi;
    }

    public Integer getHainan() {
        return hainan;
    }

    public void setHainan(Integer hainan) {
        this.hainan = hainan;
    }

    public Integer getHenan() {
        return henan;
    }

    public void setHenan(Integer henan) {
        this.henan = henan;
    }

    public Integer getHunan() {
        return hunan;
    }

    public void setHunan(Integer hunan) {
        this.hunan = hunan;
    }

    public Integer getHubei() {
        return hubei;
    }

    public void setHubei(Integer hubei) {
        this.hubei = hubei;
    }

    public Integer getBeijing() {
        return beijing;
    }

    public void setBeijing(Integer beijing) {
        this.beijing = beijing;
    }

    public Integer getTianjin() {
        return tianjin;
    }

    public void setTianjin(Integer tianjin) {
        this.tianjin = tianjin;
    }

    public Integer getHebei() {
        return hebei;
    }

    public void setHebei(Integer hebei) {
        this.hebei = hebei;
    }

    public Integer getShanxi() {
        return shanxi;
    }

    public void setShanxi(Integer shanxi) {
        this.shanxi = shanxi;
    }

    public Integer getInnermongolia() {
        return innermongolia;
    }

    public void setInnermongolia(Integer innermongolia) {
        this.innermongolia = innermongolia;
    }

    public Integer getNingxia() {
        return ningxia;
    }

    public void setNingxia(Integer ningxia) {
        this.ningxia = ningxia;
    }

    public Integer getQinghai() {
        return qinghai;
    }

    public void setQinghai(Integer qinghai) {
        this.qinghai = qinghai;
    }

    public Integer getShaanxi() {
        return shaanxi;
    }

    public void setShaanxi(Integer shaanxi) {
        this.shaanxi = shaanxi;
    }

    public Integer getGansu() {
        return gansu;
    }

    public void setGansu(Integer gansu) {
        this.gansu = gansu;
    }

    public Integer getSinkiang() {
        return sinkiang;
    }

    public void setSinkiang(Integer sinkiang) {
        this.sinkiang = sinkiang;
    }

    public Integer getSichuan() {
        return sichuan;
    }

    public void setSichuan(Integer sichuan) {
        this.sichuan = sichuan;
    }

    public Integer getGuizhou() {
        return guizhou;
    }

    public void setGuizhou(Integer guizhou) {
        this.guizhou = guizhou;
    }

    public Integer getYunnan() {
        return yunnan;
    }

    public void setYunnan(Integer yunnan) {
        this.yunnan = yunnan;
    }

    public Integer getChongqing() {
        return chongqing;
    }

    public void setChongqing(Integer chongqing) {
        this.chongqing = chongqing;
    }

    public Integer getTibet() {
        return tibet;
    }

    public void setTibet(Integer tibet) {
        this.tibet = tibet;
    }

    public Integer getLiaoning() {
        return liaoning;
    }

    public void setLiaoning(Integer liaoning) {
        this.liaoning = liaoning;
    }

    public Integer getJilin() {
        return jilin;
    }

    public void setJilin(Integer jilin) {
        this.jilin = jilin;
    }

    public Integer getHeilongjiang() {
        return heilongjiang;
    }

    public void setHeilongjiang(Integer heilongjiang) {
        this.heilongjiang = heilongjiang;
    }

    public Integer getHongkong() {
        return hongkong;
    }

    public void setHongkong(Integer hongkong) {
        this.hongkong = hongkong;
    }

    public Integer getMacao() {
        return macao;
    }

    public void setMacao(Integer macao) {
        this.macao = macao;
    }

    public Integer getTaiwan() {
        return taiwan;
    }

    public void setTaiwan(Integer taiwan) {
        this.taiwan = taiwan;
    }

    public Integer getOnline() {
        return online;
    }

    public void setOnline(Integer online) {
        this.online = online;
    }

    public Integer getOutline() {
        return outline;
    }

    public void setOutline(Integer outline) {
        this.outline = outline;
    }

    public void addTibet() {
        this.tibet = this.tibet + 1;
    }

    /**
     * 山东+1
     * 
     */
    public void addShandong() {
        this.shandong = this.shandong + 1;
    }

    /**
     * 江苏+1
     * 
     */
    public void addJiangsu() {
        this.jiangsu = this.jiangsu + 1;
    }

    /**
     * 上海+1
     * 
     */
    public void addShanghai() {
        this.shanghai = this.shanghai + 1;
    }

    /**
     * 浙江+1
     * 
     */
    public void addZhejiang() {
        this.zhejiang = this.zhejiang + 1;
    }

    /**
     * 安徽+1
     * 
     */
    public void addAnhui() {
        this.anhui = this.anhui + 1;
    }

    /**
     * 福建+1
     * 
     */
    public void addFujian() {
        this.fujian = this.fujian + 1;
    }

    /**
     * 江西+1
     * 
     */
    public void addJiangxi() {
        this.jiangxi = this.jiangxi + 1;
    }

    /**
     * 广东+1
     * 
     */
    public void addGuangdong() {
        this.guangdong = this.guangdong + 1;
    }

    /**
     * 广西+1
     * 
     */
    public void addGuangxi() {
        this.guangxi = this.guangxi + 1;
    }

    /**
     * 海南+1
     * 
     */
    public void addHainan() {
        this.hainan = this.hainan + 1;
    }

    /**
     * 河南+1
     * 
     */
    public void addHenan() {
        this.henan = this.henan + 1;
    }

    /**
     * 湖南+1
     * 
     */
    public void addHunan() {
        this.hunan = this.hunan + 1;
    }

    /**
     * 湖北+1
     * 
     */
    public void addHubei() {
        this.hubei = this.hubei + 1;
    }

    /**
     * 北京+1
     * 
     */
    public void addBeijing() {
        this.beijing = this.beijing + 1;
    }

    /**
     * 天津+1
     * 
     */
    public void addTianjin() {
        this.tianjin = this.tianjin + 1;
    }

    /**
     * 河北+1
     * 
     */
    public void addHebei() {
        this.hebei = this.hebei + 1;
    }

    /**
     * 山西+1
     * 
     */
    public void addShanxi() {
        this.shanxi = this.shanxi + 1;
    }

    /**
     * 陕西+1
     * 
     */
    public void addShaanxi() {
        this.shaanxi = this.shaanxi + 1;
    }

    /**
     * 内蒙古+1
     * 
     */
    public void addInnermongolia() {
        this.innermongolia = this.innermongolia + 1;
    }

    /**
     * 宁夏+1
     * 
     */
    public void addNingxia() {
        this.ningxia = this.ningxia + 1;
    }

    /**
     * 青海+1
     * 
     */
    public void addQinghai() {
        this.qinghai = this.qinghai + 1;
    }

    /**
     * 甘肃+1
     * 
     */
    public void addGansu() {
        this.gansu = this.gansu + 1;
    }

    /**
     * 新疆+1
     * 
     */
    public void addSinkiang() {
        this.sinkiang = this.sinkiang + 1;
    }

    /**
     * 四川+1
     * 
     */
    public void addSichuan() {
        this.sichuan = this.sichuan + 1;
    }

    /**
     * 贵州+1
     * 
     */
    public void addGuizhou() {
        this.guizhou = this.guizhou + 1;
    }

    /**
     * 云南+1
     * 
     */
    public void addYunnan() {
        this.yunnan = this.yunnan + 1;
    }

    /**
     * 重庆+1
     * 
     */
    public void addChongqing() {
        this.chongqing = this.chongqing + 1;
    }

    /**
     * 辽宁+1
     * 
     */
    public void addLiaoning() {
        this.liaoning = this.liaoning + 1;
    }

    /**
     * 吉林+1
     * 
     */
    public void addJilin() {
        this.jilin = this.jilin + 1;
    }

    /**
     * 黑龙江+1
     * 
     */
    public void addHeilongjiang() {
        this.heilongjiang = this.heilongjiang + 1;
    }

    /**
     * 香港+1
     * 
     */
    public void addHongkong() {
        this.hongkong = this.hongkong + 1;
    }

    /**
     * 澳门+1
     * 
     */
    public void addMacao() {
        this.macao = this.macao + 1;
    }

    /**
     * 台湾+1
     * 
     */
    public void addTaiwan() {
        this.taiwan = this.taiwan + 1;
    }
}

service层逻辑

// 从数据库中取出插座统计记录，该表中只有一条记录，如有变化直接更新就是
        SocketStatistics socketStatistics = socketStatisticsMapper.selectOne();

        // 根据前端传过来的插座所属省份中文名，到省份枚举类中得到对应的英文名
        // 再通过拼接的方式得到对应的方法名
        String methodName = "add"
                + ProvinceEnum.getMsgByCode(socket.getProvince());

        // 到SocketStatistics类中找到这个方法
        Method method = SocketStatistics.class.getDeclaredMethod(methodName);

        // Guava的工具类通过反射，动态调用该方法
        Invokable<SocketStatistics, Object> invokable = (Invokable<SocketStatistics, Object>) Invokable
                .from(method);
        invokable.invoke(socketStatistics);

        // 数据处理完后，更新数据库
        socketStatisticsMapper.updateByPrimaryKeySelective(socketStatistics);