java解析CSV文件三种方法(openCSV)

￡神魔★判官ぃ 2023-10-03 10:38 65阅读 0赞

### 文章目录 ###

*   *  一、简介
     *   *  1、pom.xml
     *  二、手动解析CSV文件
     *  三、openCSV解析CSV文件
     *  四、openCSV解析CSV文件(结果为实体类)
     *  五、整理完成的CsvUtils
     *  六、相关地址

--------------------

## 一、简介 ##

### 1、pom.xml ###

<dependency>
        <groupId>com.opencsv</groupId>
        <artifactId>opencsv</artifactId>
        <version>5.4</version>
    </dependency>

## 二、手动解析CSV文件 ##

//	析csv文件并转成bean（方法一）
        public static List<CsvFile> getCsvDataMethod1(MultipartFile file) {
        
            ArrayList<CsvFile> csvFileList = new ArrayList<>();
    
            InputStreamReader in = null;
            String s = null;
            try {
        
                in = new InputStreamReader(file.getInputStream(), "utf-8");
                BufferedReader bufferedReader = new BufferedReader(in);
                String line = null;
                while ((line = bufferedReader.readLine()) != null) {
        
                    String[] split = line.split(",");
                    CsvFile csvFile = new CsvFile();
                    csvFile.setName(splitResult(split[0]));
                    csvFile.setTitle(splitResult(split[1]));
                    csvFile.setNumber(splitResult(split[2]));
                    csvFile.setType(splitResult(split[3]));
                    csvFile.setPersonnel(splitResult(split[4]));
                    csvFile.setTime(splitResult(split[5]));
                    csvFileList.add(csvFile);
                }
            } catch (IOException e) {
        
                e.printStackTrace();
            }
            return csvFileList;
        }

去重引号`""`

private static String splitResult(String once) {
        
            String result = "";
            for (int i = 0; i < once.length(); i++) {
        
                if (once.charAt(i) != '"') {
        
                    result += once.charAt(i);
                }
            }
            return result;
        }

## 三、openCSV解析CSV文件 ##

/**
         * 解析csv文件并转成bean（方法二）
         *
         * @param file csv文件
         * @return 数组
         */
        public static List<String[]> getCsvDataMethod2(MultipartFile file) {
        
    
            List<String[]> list = new ArrayList<String[]>();
            int i = 0;
            try {
        
                CSVReader csvReader = new CSVReaderBuilder(
                        new BufferedReader(
                                new InputStreamReader(file.getInputStream(), "utf-8"))).build();
                Iterator<String[]> iterator = csvReader.iterator();
                while (iterator.hasNext()) {
        
                    String[] next = iterator.next();
                    //去除第一行的表头，从第二行开始
                    if (i >= 1) {
        
                        list.add(next);
                    }
                    i++;
                }
                return list;
            } catch (Exception e) {
        
                System.out.println("CSV文件读取异常");
                return list;
            }
        }

## 四、openCSV解析CSV文件(结果为实体类) ##

**工具类:**

/**
         * 解析csv文件并转成bean（方法三）
         *
         * @param file  csv文件
         * @param clazz 类
         * @param <T>   泛型
         * @return 泛型bean集合
         */
        public static <T> List<T> getCsvDataMethod3(MultipartFile file, Class<T> clazz) {
        
            InputStreamReader in = null;
            CsvToBean<T> csvToBean = null;
            try {
        
                in = new InputStreamReader(file.getInputStream(), "utf-8");
                HeaderColumnNameMappingStrategy<T> strategy = new HeaderColumnNameMappingStrategy<>();
                strategy.setType(clazz);
                csvToBean = new CsvToBeanBuilder<T>(in).withMappingStrategy(strategy).build();
            } catch (Exception e) {
        
                logger.error("数据转化失败");
                return null;
            }
            return csvToBean.parse();
        }

**实体类：**

import com.opencsv.bean.CsvBindByName;
    import lombok.Data;
    
    @Data
    public class CsvFile {
        
    
        @CsvBindByName(column = "name")
        private String name;
    
        @CsvBindByName(column = "title")
        private String title;
    
        @CsvBindByName(column = "number")
        private String number;
    
        @CsvBindByName(column = "type")
        private String type;
    
        @CsvBindByName(column = "personnel")
        private String personnel;
    
        @CsvBindByName(column = "time")
        private String time;
    }

## 五、整理完成的CsvUtils ##

import com.lydms.testopencsv.domain.CsvFile;
    import com.opencsv.CSVReader;
    import com.opencsv.CSVReaderBuilder;
    import com.opencsv.bean.CsvToBean;
    import com.opencsv.bean.CsvToBeanBuilder;
    import com.opencsv.bean.HeaderColumnNameMappingStrategy;
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.springframework.web.multipart.MultipartFile;
    
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    
    
    public class CsvUtils {
        
        private static final Logger logger = LogManager.getLogger(CsvUtils.class);
    
    
        /**
         * 解析csv文件并转成bean（方法二）
         *
         * @param file csv文件
         * @return 数组
         */
        public static List<String[]> getCsvDataMethod2(MultipartFile file) {
        
    
            List<String[]> list = new ArrayList<String[]>();
            int i = 0;
            try {
        
                CSVReader csvReader = new CSVReaderBuilder(
                        new BufferedReader(
                                new InputStreamReader(file.getInputStream(), "utf-8"))).build();
                Iterator<String[]> iterator = csvReader.iterator();
                while (iterator.hasNext()) {
        
                    String[] next = iterator.next();
                    //去除第一行的表头，从第二行开始
                    if (i >= 1) {
        
                        list.add(next);
                    }
                    i++;
                }
                return list;
            } catch (Exception e) {
        
                System.out.println("CSV文件读取异常");
                return list;
            }
        }
    
    
        /**
         * 解析csv文件并转成bean（方法三）
         *
         * @param file  csv文件
         * @param clazz 类
         * @param <T>   泛型
         * @return 泛型bean集合
         */
        public static <T> List<T> getCsvDataMethod3(MultipartFile file, Class<T> clazz) {
        
            InputStreamReader in = null;
            CsvToBean<T> csvToBean = null;
            try {
        
                in = new InputStreamReader(file.getInputStream(), "utf-8");
                HeaderColumnNameMappingStrategy<T> strategy = new HeaderColumnNameMappingStrategy<>();
                strategy.setType(clazz);
                csvToBean = new CsvToBeanBuilder<T>(in).withMappingStrategy(strategy).build();
            } catch (Exception e) {
        
                logger.error("数据转化失败");
                return null;
            }
            return csvToBean.parse();
        }
    
    
        /**
         * 解析csv文件并转成bean（方法一）
         *
         * @param file
         * @return
         */
        public static List<CsvFile> getCsvDataMethod1(MultipartFile file) {
        
            ArrayList<CsvFile> csvFileList = new ArrayList<>();
    
            InputStreamReader in = null;
            String s = null;
            try {
        
                in = new InputStreamReader(file.getInputStream(), "utf-8");
                BufferedReader bufferedReader = new BufferedReader(in);
                String line = null;
                while ((line = bufferedReader.readLine()) != null) {
        
                    String[] split = line.split(",");
                    CsvFile csvFile = new CsvFile();
                    csvFile.setName(splitResult(split[0]));
                    csvFile.setTitle(splitResult(split[1]));
                    csvFile.setNumber(splitResult(split[2]));
                    csvFile.setType(splitResult(split[3]));
                    csvFile.setPersonnel(splitResult(split[4]));
                    csvFile.setTime(splitResult(split[5]));
                    csvFileList.add(csvFile);
                }
            } catch (IOException e) {
        
                e.printStackTrace();
            }
            return csvFileList;
        }
    
        private static String splitResult(String once) {
        
            String result = "";
            for (int i = 0; i < once.length(); i++) {
        
                if (once.charAt(i) != '"') {
        
                    result += once.charAt(i);
                }
            }
            return result;
        }
    }

## 六、相关地址 ##

[参考地址:][Link 1]

https://www.cnblogs.com/xhj99/p/13536465.html

[Git地址:][Git]

https://github.com/li395092734/test-opencsv

[CSV文件][CSV]

https://files.cnblogs.com/files/blogs/604830/csvfile.zip

[Link 1]: https://www.cnblogs.com/xhj99/p/13536465.html
[Git]: https://github.com/li395092734/test-opencsv
[CSV]: https://files.cnblogs.com/files/blogs/604830/csvfile.zip