spring boot缓存excel临时文件后再操作

1. 引入poi的两个依赖

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.15</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.15</version>
</dependency>

2. controller层

package com.cdqd.app.controllers;

import com.cdqd.app.common.JsonRet;
import com.cdqd.app.exception.BizException;
import com.cdqd.app.service.TranslateService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.MultipartRequest;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Objects;

/**
 * @description:
 * @author: Rosa
 * @create: 2018-12-24 10:06
 **/
@RestController
@RequestMapping("translate")
public class TranslateController {

    @Autowired
    private TranslateService translateService;

    @PostMapping("source/name")
    public JsonRet translateSourceName(HttpServletRequest request) throws Exception{
        MultipartRequest multipartHttpServletRequest = (MultipartRequest) request;
        MultipartFile multipartFile = multipartHttpServletRequest.getFile("file");

	//如果为空，抛出异常，此处为自定义异常，如有需要请改写
        if (Objects.requireNonNull(multipartFile).isEmpty()){
            throw new BizException(4001);
        }

	//存储临时文件
        String fileName = multipartFile.getOriginalFilename();
        String prefix = fileName.substring(Objects.requireNonNull(fileName).lastIndexOf("."));
        File file = File.createTempFile(System.currentTimeMillis() + "", prefix);
        multipartFile.transferTo(file);

	//调用service对流进行具体操作
        translateService.translateSourceDatabase(new FileInputStream(file));
        return JsonRet.buildRet(0);//
    }
}

3. service层（给自己回忆用的，针对性强，读者没有必要往下看了）

接口： TranslateService.java

package com.cdqd.app.service;

import java.io.InputStream;

public interface TranslateService {

    void translateSourceDatabase(InputStream inputStream);
}

实现文件： TranslateServiceImpl.java

package com.cdqd.app.service.impl;

import com.cdqd.app.common.StringUtil;
import com.cdqd.app.entity.DatabaseEntity;
import com.cdqd.app.entity.TableEntity;
import com.cdqd.app.exception.BizException;
import com.cdqd.app.mapper.ColumnMapper;
import com.cdqd.app.mapper.DatabaseMapper;
import com.cdqd.app.mapper.TableMapper;
import com.cdqd.app.model.Column;
import com.cdqd.app.model.Database;
import com.cdqd.app.model.Table;
import com.cdqd.app.service.TableService;
import com.cdqd.app.service.TranslateService;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @description:
 * @author: Rosa
 * @create: 2018-12-24 10:04
 **/
@Service
public class TranslateServiceImpl implements TranslateService {

    @Autowired
    private DatabaseMapper databaseMapper;

    @Autowired
    private TableMapper tableMapper;

    @Autowired
    private ColumnMapper columnMapper;

    @Autowired
    private TableService tableService;

    @Override
    public void translateSourceDatabase(InputStream inputStream) {
        Map<String, Map<String, TableEntity>> databaseMap = getTransMap(inputStream);
        //遍历所有库
        if (databaseMap != null) {
            for (String databaseEnName : databaseMap.keySet()) {
                Database database = new Database();
                database.setDatabaseEnName(databaseEnName);
                //如果库存在则开始遍历表
                if (databaseMapper.selectOne(database) != null) {
                    Integer databaseId = databaseMapper.selectOne(database).getDatabaseId();
                    //MapKey("tableEnName")
                    Map<String, TableEntity> dbTableMap = tableService.getTableEntityMap(databaseId);

                    //<表英文名， 表实体>
                    Map<String, TableEntity> excelTableMap = databaseMap.get(databaseEnName);

                    //遍历数据库map的表实体
                    for (String dbTableEnName : dbTableMap.keySet()) {
                        TableEntity dbTableEntity = dbTableMap.get(dbTableEnName);
                        //如果excel数据中有这边的表
                        if (excelTableMap.containsKey(dbTableEnName)) {
                            TableEntity excelTableEntity = excelTableMap.get(dbTableEnName);
                            //源表表名翻译
                            if (!StringUtil.isEmpty(excelTableEntity.getTableCnName())) {
                                Table table = new Table();
                                table.setTableId(dbTableEntity.getTableId());
                                table.setTableCnName(excelTableEntity.getTableCnName());
                                tableMapper.updateByPrimaryKeySelective(table);
                            }
                            //如果列不为空的话
                            if (dbTableEntity.getColumnList() != null && excelTableEntity.getColumnMap() != null) {
                                //<列英文名， 列实体>
                                Map<String, Column> excelColumnMap = excelTableEntity.getColumnMap();
                                for (Column dbColumn : dbTableEntity.getColumnList()) {
                                    if (excelColumnMap.containsKey(dbColumn.getColumnEnName())) {
                                        String columnCnName = excelColumnMap.get(dbColumn.getColumnEnName()).getColumnCnName();
                                        if (!StringUtil.isEmpty(columnCnName)) {
                                            //如果列中文名不为空，翻译列名
                                            Column column = new Column();
                                            column.setColumnId(dbColumn.getColumnId());
                                            column.setColumnCnName(columnCnName);
                                            columnMapper.updateByPrimaryKeySelective(column);
                                        }

                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
//        return TRANS_MAP;
    }

    private Map<String, Map<String, TableEntity>> getTransMap(InputStream inputStream) {
        Map<String, Map<String, TableEntity>> databaseMap = new HashMap<>();
        try {
            XSSFWorkbook workbook = new XSSFWorkbook(inputStream);
            XSSFSheet sheet = workbook.getSheetAt(0);
            for (int row = 1; row < sheet.getLastRowNum(); row++) {
                XSSFRow xssfRow = sheet.getRow(row);
                if (xssfRow.getCell(0) == null) {
                    continue;
                }
                String databaseName = String.valueOf(xssfRow.getCell(0));
                String tableEnName = String.valueOf(xssfRow.getCell(1));
                String tableCnName = String.valueOf(xssfRow.getCell(2));
                String columnEnName = String.valueOf(xssfRow.getCell(3));
                String columnCnName = String.valueOf(xssfRow.getCell(4));

                Column column = new Column();
                column.setColumnEnName(columnEnName);
                column.setColumnCnName(columnCnName);

                if (tableEnName == null) {
                    continue;
                }
                if (databaseMap.containsKey(databaseName)) {

                    //<表英文名， 表实体>
                    Map<String, TableEntity> excelTableMap = databaseMap.get(databaseName);
                    //如果表存在，获取那个表实体
                    if (excelTableMap.containsKey(tableEnName)) {
                        TableEntity excelTableEntity = excelTableMap.get(tableEnName);

                        if (columnEnName != null && !columnEnName.equals("")) {
                            if (excelTableEntity.getColumnMap() != null) {
                                Map<String, Column> columnMap = excelTableEntity.getColumnMap();
                                columnMap.put(columnEnName, column);
                                excelTableEntity.setColumnMap(columnMap);
                            } else {
                                Map<String, Column> columnMap = new HashMap<>();
                                columnMap.put(columnEnName, column);
                                excelTableEntity.setColumnMap(columnMap);
                            }
                        }
                        excelTableMap.put(tableEnName, excelTableEntity);
                    } else {
                        //表不存在时插入表
                        TableEntity excelTableEntity = new TableEntity();
                        excelTableEntity.setTableEnName(tableEnName);
                        excelTableEntity.setTableCnName(tableCnName);
                        if (columnEnName != null && !columnEnName.equals("")) {
                            Map<String, Column> columnMap = new HashMap<>();
                            columnMap.put(columnEnName, column);
                            excelTableEntity.setColumnMap(columnMap);
                        }
                        excelTableMap.put(tableEnName, excelTableEntity);
                    }
                } else {
                    Map<String, TableEntity> excelTableMap = new HashMap<>();
                    TableEntity excelTableEntity = new TableEntity();
                    excelTableEntity.setTableEnName(tableEnName);
                    excelTableEntity.setTableCnName(tableCnName);
                    if (columnEnName != null && !columnEnName.equals("")) {
                        Map<String, Column> columnMap = new HashMap<>();
                        columnMap.put(columnEnName, column);
                        excelTableEntity.setColumnMap(columnMap);
                    }
                    excelTableMap.put(tableEnName, excelTableEntity);
                    databaseMap.put(databaseName, excelTableMap);
                }
            }
            return databaseMap;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}