Java实用语句
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Java实用语句

   一些代码   0 评论   1302 浏览

List＜实体类＞多属性去重

list = list.stream().collect(
        Collectors.collectingAndThen(
                Collectors.toCollection(
                        () -> new TreeSet<>(Comparator.comparing(o -> o.getProjectId() + ";" + o.getUserId()))
                ), ArrayList::new
        )
);

List集合根据对象某个属性去重

designQualifications.stream()
.filter(distinctByKey(DesignQualification::getNameCode))
.collect(Collectors.toList());

private static <T> Predicate<T> distinctByKey(Function<? super T, Object> keyExtractor) {
    Map<Object, Boolean> seen = new ConcurrentHashMap<>();
    return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
}

List按某个String字段（可转double）排序

arrayList = arrayList.stream()
        .sorted(Comparator.comparing(c -> Double.valueOf(c.getTaxPoints())))
        .collect(Collectors.toList());
Collections.reverse(arrayList);

List根据某日期属性分组

public R<Map<String,List<Schedule>>> findListByDate(Schedule schedule) {
    List<Schedule> list = scheduleService.list(Condition.getQueryWrapper(schedule));
    for (Schedule scheduleTemp : list) {
        scheduleTemp.setFormatScheduleDate(DateUtil.format(scheduleTemp.getScheduleDate(), "yyyy-MM-dd"));
    }
    Map<String,List<Schedule>> resultList = list.stream().collect(Collectors.groupingBy(Schedule::getFormatScheduleDate));
    return R.data(resultList);
}

List2Tree

public static List<Person> listToTree(List<Person> list) {
    Map<String, List<Person>> parentIdMap = list.stream().collect(Collectors.groupingBy(Person::getParentId));
    list.forEach(p -> p.setChildList(parentIdMap.get(p.getId())));
    return list.stream().filter(p -> p.getParentId().equals("0")).collect(Collectors.toList());
}

相差月份

String text1 = "2020-08-02";
Temporal temporal1 = LocalDate.parse(text1);
String text2 = "2020-09-01";
Temporal temporal2 = LocalDate.parse(text2);
// 方法返回为相差月份
long l = ChronoUnit.MONTHS.between(temporal1, temporal2);
System.out.println(l);

Stream分页

List<User> list = new ArrayList<>();
List<User> subList = list.stream().skip((pageNo - 1) * pageSize).limit(pageSize).
        collect(Collectors.toList());

树状结构根据id递归查询子集

SELECT
    t3.*
FROM (
    SELECT
        t1.*,
        t2.*,
        IF(FIND_IN_SET(parent_id, @pids) > 0, @pids := CONCAT(@pids, ',', id), '0') AS isChild
    FROM (
        SELECT * FROM admin_proeducontent_category ORDER BY parent_id,id
    ) AS t1,
    ( SELECT @pids := 'xxxxxxxxxxxxxx') AS t2
) t3
WHERE t3.isChild != '0'

如果mybatis报错则给mapper接口方法添加注解，@SqlParser(filter = true)

自定义排序上下移

<select id="getDownOne" resultMap="BaseResultMap">
    SELECT * from oa_publish_train_course WHERE
    ( `sort` &gt; #{originSort}  OR `sort`=(SELECT MAX(`sort`) FROM oa_publish_train_course where publish_train_id = #{publishTrainId}))
    AND publish_train_id = #{publishTrainId}
    AND is_deleted = 0
    ORDER BY `sort` ASC limit 1
</select>
<select id="getUpOne" resultMap="BaseResultMap">
    SELECT * from oa_publish_train_course WHERE
    ( `sort` &lt; #{originSort}  OR `sort`=(SELECT MIN(`sort`) FROM oa_publish_train_course where publish_train_id = #{publishTrainId}))
    AND publish_train_id = #{publishTrainId}
    AND is_deleted = 0
    ORDER BY `sort` DESC limit 1
</select>
@Override
@Transactional
public void moveUp(OaPublishTrainCourse request) {
    try {
        //获取原课程
        OaPublishTrainCourse origin = this.baseMapper.selectById(request.getId());
        Long originSort = origin.getSort();
        //获取原课程的上一个课程
        OaPublishTrainCourse up = this.baseMapper.getUpOne(originSort, origin.getPublishTrainId());
        Long upSort = up.getSort();
        //如果是同一个就不用改动位置
        if(up.getId() == origin.getId())
            return;
        //不然就是替换两个sort
        OaPublishTrainCourse originUpdate = new OaPublishTrainCourse();
        originUpdate.setId(origin.getId());
        originUpdate.setSort(upSort);
        this.baseMapper.updateById(originUpdate);
        OaPublishTrainCourse upUpdate = new OaPublishTrainCourse();
        upUpdate.setId(up.getId());
        upUpdate.setSort(originSort);
        this.baseMapper.updateById(upUpdate);
    } catch (Exception e) {
        e.printStackTrace();
        throw new ServiceException(DesignResultCode.ERR_DATA_OPER_ERROR);
    }
}
@Override
@Transactional
public void moveDown(OaPublishTrainCourse request) {
    try {
        //获取原课程
        OaPublishTrainCourse origin = this.baseMapper.selectById(request.getId());
        Long originSort = origin.getSort();
        //获取原课程的下一个课程
        OaPublishTrainCourse down = this.baseMapper.getDownOne(originSort, origin.getPublishTrainId());
        Long downSort = down.getSort();
        //如果是同一个就不用改动位置
        if(down.getId() == origin.getId())
            return;
        //不然就是替换两个sort
        OaPublishTrainCourse originUpdate = new OaPublishTrainCourse();
        originUpdate.setId(origin.getId());
        originUpdate.setSort(downSort);
        this.baseMapper.updateById(originUpdate);
        OaPublishTrainCourse upUpdate = new OaPublishTrainCourse();
        upUpdate.setId(down.getId());
        upUpdate.setSort(originSort);
        this.baseMapper.updateById(upUpdate);
    } catch (NullPointerException e) {
        throw new ServiceException(DesignResultCode.ERR_DATA_OPER_ERROR);
    }
}


add时执行baseMapper.updateAddOne();
@Update("update oa_publish_train_course set `sort` = (`sort` + 1)")
int updateAddOne();

远程调用模型

远程调用 blade-resource模块 OssEndpoint类 /put-file接口
OaReserveTeam oaReserveTeam = ossClient.getTeam().getData();
=============
blade-resource-api模块 IOssClient接口
@FeignClient(value = "blade-customer", fallback = IOssFallback.class)
public interface IOssClient {
    String API_PREFIX = "/reserveTeam";
    String GET_TEAM = API_PREFIX + "/getTeam";

    @ApiOperation(value="获取团队")
    @GetMapping(GET_TEAM)
    public R<OaReserveTeam> getTeam();
}
=============
blade-resource-api模块 IOssFallback类
@Component
public class IOssFallback implements IOssClient {
    @Override
    public R<OaReserveTeam> getTeam() {
        return R.fail("客户端获取团队时远程调用失败");
    }
}
=============
blade-customer模块 ReserveTeamController类
@GetMapping("/getTeam")
@ApiOperation("获取客户团队")
public R<OaReserveTeam> getTeam(){
    OaReserveTeam oaReserveTeam = oaReserveTeamMapper
        .selectOne(new LambdaQueryWrapper<OaReserveTeam>()
        .eq(OaReserveTeam::getDeptId,AuthUtils.getDeptIdForCustomer()));
    return R.data(oaReserveTeam);
}

邮箱验证码

/***
 * 获取邮箱验证码
 * @param sendTo
 * @return 实体对象
 */
@ApiOperation(value="获取邮箱验证码", notes="获取邮箱验证码")
@ApiImplicitParam(name = "sendTo", value = "邮箱地址", required = true, dataType = "String", paramType = "query")
@GetMapping("/getEmailVerificationCode")
public R<?> getEmailVerificationCode(String sendTo){
    StEmailList stEmailList = new StEmailList();
    stEmailList.setSender("");
    stEmailList.setSendTo(sendTo);
    stEmailList.setPriority(10);
    stEmailList.setCreatedOn(LocalDateTime.now());
    stEmailList.setIsSend(0);
    stEmailList.setSendTimes(0);
    //查询模板写入内容
    StTemplateBase stTemplate = stTemplateService.getOne(new QueryWrapper<StTemplateBase>().eq("template_key", "company_bind_email"));
    stEmailList.setSubject(stTemplate.getName());
    stEmailList.setMsgType(stTemplate.getType());
    //生成邮箱验证码
    String verificationCode = RandomUtil.getRandom();
    stEmailList.setMsg(stTemplate.getContent().replace("${VerifyCode-company-email}",verificationCode));
    stEmailListService.save(stEmailList);
    //存入redis 设置过期时间5分钟
    RedisUtil.redisService.add(Setting.COMPANY_BIND_EMAIL_KEY + sendTo, verificationCode, 5, TimeUnit.MINUTES);
    return R.data("发送成功！");
}

邮箱服务5s轮询邮件列表中未发送的邮件执行发送

List<StEmailList> stEmailLists = stEmailListMapper.selectList(new QueryWrapper<StEmailList>().eq("is_send", 0).lt("send_times", 5).orderByDesc("priority"));
if (stEmailLists.size() == 0) {
    return;
}
for (StEmailList item : stEmailLists) {
    StEmailList newItem = new StEmailList();
    newItem.setId(item.getId());
    try {
        //发送邮件
        mailService.sendHtmlMail(item.getSendTo(), item.getSubject(), item.getMsg());
        //发送成功
        newItem.setIsSend(1);
        newItem.setResult("true");
    } catch (Exception e) {
        e.printStackTrace();
        logger.error("邮箱发送失败", e);
        //发送失败
        newItem.setIsSend(0);
        newItem.setResult("false");
    }
    //更新
    newItem.setSendTimes(item.getSendTimes() + 1);
    newItem.setSendOn(LocalDateTime.now());
    stEmailListMapper.updateById(newItem);
}
public void sendHtmlMail(String to,String subject,String content) throws Exception {
    MimeMessage mimeMessage = mailSender.createMimeMessage();
    MimeMessageHelper helper = new MimeMessageHelper(mimeMessage,true);
    helper.setFrom(from);
    helper.setTo(to);
    helper.setSubject(subject);
    helper.setText(content,true);
    mailSender.send(mimeMessage);
}

下载文件

@GetMapping(value = "/downCert", produces = "application/octet-stream")
@ApiOperation(value = "下载", notes = "下载")
public void downCert(Long id, HttpServletResponse response) throws IOException {
    // 获取
    PaCertificateBase cert = service.getById(id);
    Long fileId = cert.getFileId();
    if (fileId != null) {
        StFiles certFile = filesService.getById(fileId);
        FileUtil.downloadFile(response,  "证书文件_" + DateUtil.format(new Date(), "yyyyMMdd") + ".pdf", certFile.getFileUrl());
    }
}
/**
 * 下载本地文件
 * @param response
 * @param name
 * @param filePath
 */
public static void downloadFile(HttpServletResponse response, String name, String filePath) throws IOException {
    response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(name, "UTF-8"));
    response.setContentType("multipart/form-data");
    InputStream in = getInputStreamFromUrl(filePath); //获取下载文件的输入流
    int count = 0;
    byte[] by = new byte[1024];
    //通过response对象获取OutputStream流
    OutputStream out =  response.getOutputStream();
    while((count = in.read(by)) != -1) {
        out.write(by, 0, count);//将缓冲区的数据输出到浏览器
    }
    in.close();
    out.flush();
    out.close();
}

/**
 * 通过网络地址获取文件InputStream
 *
 * @param fileUrl 文件下载链接
 * @return
 */
private static InputStream getInputStreamFromUrl(String fileUrl) {
    URL url = null;
    InputStream is = null;
    try {
        url = new URL(fileUrl);
    } catch (MalformedURLException e) {
        e.printStackTrace();
    }
    try {
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setDoInput(true);
        conn.connect();
        is = conn.getInputStream();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return is;
}

DOC模板生成下载

/**
 * 生成数据存证打印模板
 */
@ApiOperation(value="生成数据存证打印模板")
@GetMapping(value = "/exportPrintTemplate", produces = "application/octet-stream")
public void exportPrintTemplate(String id, HttpServletResponse response) throws Exception {
    // 渲染数据
    Map<String, String> params = service.queryApplicationData(id);
    ClassPathResource classPathResource = new ClassPathResource("数据存证打印模板.docx");
    InputStream inputStream = classPathResource.getInputStream();
    response.setContentType("multipart/form-data");
    response.addHeader("Content-Disposition", "attachment;filename="
            + URLEncoder.encode("数据存证打印模板", "UTF-8")
            + "_" + DateUtil.formatDate(new Date(), "yyyyMMdd") + ".docx");
    OutputStream out = response.getOutputStream();
    XWPFTemplate template = XWPFTemplate.compile(inputStream).render(params);
    template.writeAndClose(out);
}

EasyPOI/POI版本

<!--easypoi 导出excel依赖-->
<dependency>
    <groupId>cn.afterturn</groupId>
    <artifactId>easypoi-base</artifactId>
    <version>4.2.0</version>
    <exclusions>
        <exclusion>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>cn.afterturn</groupId>
    <artifactId>easypoi-web</artifactId>
    <version>4.2.0</version>
</dependency>
<dependency>
    <groupId>cn.afterturn</groupId>
    <artifactId>easypoi-annotation</artifactId>
    <version>4.2.0</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml-schemas</artifactId>
    <version>4.1.2</version>
</dependency>

滑动验证码

<!-- AJ-Captcha -->
<dependency>
    <groupId>com.github.anji-plus</groupId>
    <artifactId>captcha-spring-boot-starter</artifactId>
    <version>1.2.7</version>
</dependency>

OR

<dependency>
    <groupId>com.github.anji-plus</groupId>
    <artifactId>captcha</artifactId>
    <version>1.2.7</version>
</dependency>
/**
 * 获取滑动验证码
 * @param data
 * @param request
 * @return
 */
@PostMapping("/captcha/get")
public ResponseModel captchaGet(@RequestBody CaptchaVO data, HttpServletRequest request) {
    return captchaController.get(data, request);
}

/**
 * 检查滑动验证码(do something)
 * @param data
 * @param request
 * @return
 */
@PostMapping("/captcha/check")
public ResponseModel captchaCheck(@RequestBody CaptchaVO data, HttpServletRequest request) {
    ResponseModel check = captchaController.check(data, request);
    return check;
}
//repCode  0000  无异常，代表成功
//repCode  9999  服务器内部异常
//repCode  0011  参数不能为空
//repCode  6110  验证码已失效，请重新获取
//repCode  6111  验证失败
//repCode  6112  获取验证码失败,请联系管理员
aj:
  captcha:
    aes-status: false
    water-mark:

本文由 RawChen 发表， 最后编辑时间为：2022-12-23 19:29
如果你觉得我的文章不错，不妨鼓励我继续写作。

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