CSV 文件解析

墨蓝 2022-08-23 12:55 279阅读 0赞

介绍

在很多时候，数据是以CSV文件格式存放的。在提取CSV数据时，我们借助javacsv这个开源工具来处理，还是比较方便。

javacsv in pom.xml of Maven

<dependency>
    			<groupId>net.sourceforge.javacsv</groupId>
    			<artifactId>javacsv</artifactId>
    			<version>2.0</version>
    		</dependency>

import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.util.Map;
    import java.util.concurrent.ConcurrentHashMap;
    
    import org.apache.commons.io.FilenameUtils;
    import org.apache.commons.lang.StringUtils;
    import org.apache.log4j.LogManager;
    import org.apache.log4j.Logger;
    
    import util.CommonTool;
    
    import com.csvreader.CsvReader;
    
    /**
     * @author shengshu
     * 
     */
    public class CsvCmHandle {
    	private static final Logger logger = LogManager.getLogger(CsvCmHandle.class);
    
    	private static Map<String, Map<String, String>> cmMap = new ConcurrentHashMap<String, Map<String, String>>();
    
    	/**
    	 * *
    	 * <p>
    	 * Read CSV file and store records into Map.
    	 * 
    	 * @param csvFilePath
    	 * @return
    	 */
    	public static Map<String, Map<String, String>> csvCmHandle(String csvFilePath) {
    		logger.info("CSV File: " + csvFilePath);
    
    		Map<String, String> cmRecordMap = null;
    		String fileName = FilenameUtils.getBaseName(csvFilePath);
    
    		try {
    			CsvReader csvReader = new CsvReader(csvFilePath);
    
    			csvReader.readHeaders();
    
    			// Get CSV header array
    			String[] csvHeaderArray = csvReader.getHeaders();
    
    			// Ignore the headers when start to read records
    			while (csvReader.readRecord()) {
    				String[] csvRecordValueArray = csvReader.getValues();
    				int csvRecordValueArrayLength = csvRecordValueArray.length;
    
    				StringBuilder lineRecordStringBuilder = new StringBuilder();
    
    				for (int index = 0; index < csvRecordValueArrayLength; index++) {
    					lineRecordStringBuilder.append(csvRecordValueArray[index]);
    				}
    
    				// Continue next cycle when it's empty record
    				if (StringUtils.trimToEmpty(lineRecordStringBuilder.toString()).equals("")) {
    					break;
    				}
    
    				int csvHeaderArrayLength = csvHeaderArray.length;
    				cmRecordMap = new ConcurrentHashMap<String, String>();
    
    				for (int index = 0; index < csvHeaderArrayLength; index++) {
    					String fieldName = csvHeaderArray[index];
    
    					String fieldValue = StringUtils.trimToEmpty(CommonTool.convertReserveSymbel(csvReader.get(fieldName), false));
    					logger.info("Field Name = Value: " + fieldName + " = " + fieldValue);
    
    					// Put fieldName(Key) and fieldValue(Value) into Map as one record
    					cmRecordMap.put(fieldName, fieldValue);
    				}
    			}
    
    			csvReader.close();
    
    			// Store entire CSV records into Map(Key: fileName; Value: recordMap)
    			cmMap.put(fileName, cmRecordMap);
    		} catch (FileNotFoundException fnfe) {
    			fnfe.printStackTrace();
    		} catch (IOException ioe) {
    			ioe.printStackTrace();
    		}
    
    		return cmMap;
    	}
    }