CSV文件读写操作

深碍√TFBOYSˉ_ 2022-09-04 02:45 303阅读 0赞

### CSV文件读写操作 ###

*  CSVOperationUtil
 *  LinkID

# CSVOperationUtil #

import com.alibaba.fastjson.JSON;
    import com.opencsv.CSVReader;
    import com.opencsv.CSVReaderBuilder;
    import com.opencsv.CSVWriter;
    import com.opencsv.bean.CsvToBean;
    import com.opencsv.bean.CsvToBeanBuilder;
    import com.opencsv.bean.StatefulBeanToCsv;
    import com.opencsv.bean.StatefulBeanToCsvBuilder;
    import com.opencsv.exceptions.CsvDataTypeMismatchException;
    import com.opencsv.exceptions.CsvException;
    import com.opencsv.exceptions.CsvRequiredFieldEmptyException;
    import com.opencsv.exceptions.CsvValidationException;
    
    import java.io.*;
    import java.nio.charset.StandardCharsets;
    import java.util.*;
    
    /** * @Author zhaozhen * @Date 2021/8/9 8:42 下午 * @Version 1.0 */
    public class CSVOperationUtil { 
        /** * 使用Javabean来读取文件 * @param filePath * @param clazz * @param <T> * @return * @throws FileNotFoundException */
        public static <T> List<T> readToBean(String filePath,Class<T> clazz) throws FileNotFoundException { 
            Reader reader = new InputStreamReader(new FileInputStream(filePath), StandardCharsets.UTF_8);
            CSVReader csvReader = new CSVReaderBuilder(reader).build();
            CsvToBean<T> csvToBean = new CsvToBeanBuilder<T>(csvReader)
                    .withSeparator(CSVWriter.DEFAULT_SEPARATOR)
                    .withQuoteChar(CSVWriter.NO_QUOTE_CHARACTER)
                    .withType(clazz)
                    .build();
            List<T> list = csvToBean.parse( );
            return list;
        }
    
        /** * 从filePath中读出内容，按行读，返回List<String[]> * * @param filePath * @return * @throws IOException * @throws CsvValidationException */
        public static List<String[]> readerByLine(String filePath) throws IOException, CsvValidationException { 
            CSVReader reader = new CSVReader(new FileReader(filePath));
            String[] nextLine;
            List<String[]> tmpList = new ArrayList<>();
            while ((nextLine = reader.readNext()) != null) { 
                tmpList.add(nextLine);
            }
            return tmpList;
        }
    
        /** * 一次全部读出，返回List<String[]> * @param filePath * @return * @throws IOException * @throws CsvValidationException */
        public static List<String[]> readerByAll(String filePath) throws IOException, CsvException { 
            CSVReader reader = new CSVReader(new FileReader(filePath));
            List<String[]> tmpList = reader.readAll();
            return tmpList;
        }
    
    
        /** * csv写入 * @param filePath * @param list * @param <T> */
        public static<T> void writeToFile(String filePath,List<T> list) throws CsvRequiredFieldEmptyException, CsvDataTypeMismatchException, IOException { 
            Writer writer = new FileWriter(filePath);
            CSVWriter csvWriter = new CSVWriter(writer, CSVWriter.DEFAULT_SEPARATOR, CSVWriter.NO_QUOTE_CHARACTER, '\\', "\n");
            StatefulBeanToCsv beanToCsv = new StatefulBeanToCsvBuilder(writer)
                    .withQuotechar(CSVWriter.NO_QUOTE_CHARACTER)
                    .withSeparator(CSVWriter.DEFAULT_SEPARATOR)
                    .withEscapechar('\\')
                    .build();
            beanToCsv.write(list);
            csvWriter.close();
            writer.close();
        }
    
        public static <T> void writeToFileByStrings (String filePath, List<T> List) throws IOException { 
            Writer writer = new FileWriter(filePath);
            CSVWriter csvWriter = new CSVWriter(writer, CSVWriter.DEFAULT_SEPARATOR,
                    CSVWriter.NO_QUOTE_CHARACTER, '\\', "\n");
    		
    		//将Javabean转换为string[]，然后按行写入
            // for (LinkID linkID : linkIDList) { 
            // csvWriter.writeNext(new String[]{linkID.getMtl_id(), linkID.getMesh(), linkID.getRoad_id(), linkID.getDb_road_id()});
            // }
                    //csvWriter.close();
        }
    
        /** * 将任意类型转换成字符串 * @param value * @param <T> * @return */
        public static <T> String beanToString(T value) { 
            Class<?> clazz = value.getClass();
            if(clazz == int.class || clazz == Integer.class) { 
                return value + "";
            }else if(clazz == String.class) { 
                return (String)value;
            }else if(clazz == long.class || clazz == Long.class) { 
                return value + "";
            }else { 
                return JSON.toJSONString(value);
            }
        }
    
    
    
        public static void main(String[] args) throws IOException, CsvRequiredFieldEmptyException, CsvDataTypeMismatchException { 
            List<LinkID> linkIDList;
            linkIDList = readToBean("/Users/zhaozhen/Work/document/excel/tmp_link_id.csv",LinkID.class);
            String csvFilePath = "/Users/zhaozhen/Work/document/excel/testWrite.csv";
            writeToFile(csvFilePath,linkIDList);
          
        }
    }

# LinkID #

/** * @Author zhaozhen * @Date 2021/8/9 8:55 下午 * @Version 1.0 */
    @Data
    public class LinkID { 
        @CsvBindByPosition(position = 0)
        String mtl_id;
        @CsvBindByPosition(position = 1)
        String mesh;
        @CsvBindByPosition(position = 2)
        String road_id;
        @CsvBindByPosition(position = 3)
        String db_road_id;
    
    
        @Override
        public boolean equals(Object object){ 
            boolean meshFlag =false;
            boolean dbRoadIdFlag = false;
            boolean roadFlag =false;
    
            if(object instanceof LinkID){ 
                LinkID linkID = (LinkID) object;
                if(this.mtl_id.equals(linkID.mtl_id)){ 
                    if((this.mesh == null && linkID.mesh == null)||(this.mesh == null && linkID.mesh != null) ||(linkID.mesh == null && this.mesh != null) || this.mesh.equals(linkID.mesh)){ 
                        meshFlag = true;
                    }
                    if((this.road_id == null && linkID.road_id == null)||(this.road_id == null && linkID.road_id != null) ||(linkID.road_id == null && this.road_id != null)|| this.road_id.equals(linkID.road_id)){ 
                        roadFlag = true;
                    }
    
                    if((this.db_road_id == null && linkID.db_road_id == null)||(this.db_road_id == null && linkID.db_road_id != null) ||(linkID.db_road_id == null && this.db_road_id != null) || this.db_road_id.equals(linkID.db_road_id)){ 
                        dbRoadIdFlag = true;
                    }
                    }
            }
    
            if(meshFlag&&dbRoadIdFlag&&roadFlag){ 
                return true;
            }
            return false;
        }
    
        @Override
        public int hashCode() { 
            int hash=mtl_id.hashCode();
            if(mesh != null){ 
                hash+= mesh.hashCode();
            }
            if(road_id != null){ 
                hash+=road_id.hashCode();
            }
            if(db_road_id != null){ 
                hash+=db_road_id.hashCode();
            }
            return hash;
        }
    }