java读、写、追加CSV

    <dependency>  
            <groupId>commons-lang</groupId>  
            <artifactId>commons-lang</artifactId>  
            <version>2.5</version>  
        </dependency>  
           
        <dependency>  
            <groupId>org.ostermiller</groupId>  
            <artifactId>utils</artifactId>  
            <version>1.07.00</version>  
        </dependency>  

Csv文件写操作类代码

    import java.io.File;  
    import java.io.FileOutputStream;  
    import java.io.FileWriter;  
    import java.io.IOException;  
    import java.util.Date;  
      
    import org.apache.commons.lang.time.DateFormatUtils;  
      
    import com.Ostermiller.util.CSVPrint;  
    import com.Ostermiller.util.CSVPrinter;  
      
    /**  
     *   
     * @author alex.wang  
     * csv文件写入  
     *  
     */  
    public class CsvFilePrinter{     
        
        private CSVPrint csvPrint;  
      
        /**  
         *   
         * @param fileName 文件路径  
         * @param append 是否支持追加  
         * @throws IOException  
         */  
        public CsvFilePrinter(String fileName,boolean append) throws IOException {   
            File file = new File(fileName);  
            if(!file.exists()){  
                csvPrint = new CSVPrinter(new FileWriter(fileName,append));  
                init();  
            }else{  
                csvPrint = new CSVPrinter(new FileWriter(fileName,append));  
                if(!append){  
                    init();  
                }  
            }  
               
        }  
          
        public void init() throws IOException{  
            write(new String[]{"id","mac","val","date"});  
        }  
         
        public void write(String[] values) throws IOException {    
            csvPrint.writeln(values);  
        }     
         
        public static void main(String[] args) throws Exception {     
            String csvFile = "demo".concat("-").concat(DateFormatUtils.format(new Date(), "yyyyMMdd")).concat(".csv");  
            CsvFilePrinter print = new CsvFilePrinter(csvFile,false);  
              
            for(int i=0;i<10;i++){  
                print.write(new String[]{"50001"+i,"C914"+i,Integer.toString(-80+i),DateFormatUtils.format(new Date(), "yyyy-MM-dd")});  
            }  
          
        }     
        
    }  

Csv文件解析类代码

    import java.io.File;  
    import java.io.FileInputStream;  
    import java.io.IOException;  
    import java.io.InputStream;  
      
    import com.Ostermiller.util.ExcelCSVParser;  
    import com.Ostermiller.util.LabeledCSVParser;  
      
    /**  
     *   
     * @author alex.wang  
     * csv文件解析器  
     *  
     */  
    public class CsvFileParser{     
        
        private LabeledCSVParser csvParser;//csv解析器，对于第一行的表头信息，自动加载为索引关键字     
        
        private int currLineNum = -1;//文件所读到行数     
        
        private String[] currLine = null;//用来存放当前行的数据    
           
        
        /*   
         *  构造函数，   
         *  Param: in InputStream 要解析的信息流   
         *  throws IOException   
         */      
        
        public CsvFileParser(InputStream in) throws IOException {    
                csvParser = new LabeledCSVParser(new ExcelCSVParser(in));    
                currLineNum = csvParser.getLastLineNumber();    
        }  
          
        public CsvFileParser(String fileName) throws IOException {   
            InputStream in = new FileInputStream(fileName);  
            csvParser = new LabeledCSVParser(new ExcelCSVParser(in));    
            currLineNum = csvParser.getLastLineNumber();   
        }  
          
        /*   
         * 检查是否还有数据   
         *   
         * return ture 还有一行数据，false 没有数据   
         */    
        public boolean hasMore() throws IOException {    
            currLine = csvParser.getLine();    
            currLineNum = csvParser.getLastLineNumber();    
            if (null == currLine)    
                return false;    
            return true;    
        }     
        
        /*   
         * 返回当前行数据，关键字所指向的数据   
         * param:String filedName 该行的表头   
         * return:String 返回当前行数据，关键字所指向的数据   
         */    
        public String getByFieldName(String fieldName) {    
            return csvParser.getValueByLabel(fieldName);    
        }     
        
        /*   
         * 关闭解析器   
         *   
         *    
         */    
        public void close() throws IOException {    
            csvParser.close();     
        }     
        
        /*   
         * 读取当前行数据   
         *   
         *  return String[] 读取当前行数据   
         */    
        public String[] readLine() throws IOException {    
            currLine = csvParser.getLine();     
            currLineNum = csvParser.getLastLineNumber();     
            return currLine;    
        }     
        
       public int getCurrLineNum(){     
             return currLineNum;     
       }      
        
        public static void main(String[] args) throws Exception {     
        
             //创建解析信息流    
            InputStream in=new FileInputStream(new File("demo.csv"));     
        
           //实例解析器CsvFileParser     
            CsvFileParser parser=new CsvFileParser(in);     
        
           //读取数据    
            while(parser.hasMore()){    
                   
                System.out.print(parser.getByFieldName("time")+" ");//time 系表头数据    
                System.out.print(parser.getByFieldName("total")+" ");    
                   
            }    
               
            parser.close();    
                
        
        }     
        
    }