滴水穿石--Java 操作CSV文件

csv文件操作库opencsv.jar下载地址：http://sourceforge.net/projects/opencsv/

1、基本的文件读写

import java.io.File;

import java.io.FileReader;

import java.io.FileWriter;

import java.util.List;



import au.com.bytecode.opencsv.CSVReader;

import au.com.bytecode.opencsv.CSVWriter;



public class CSVUtils {



 /**

  * 将数据写入csv文件

  * @param data 待写入的数据

  * @throws Exception 抛出异常

  */

 public static void writeToCSV(String[][] data) throws Exception{

        File file = new File("test.csv");

        CSVWriter writer = new CSVWriter(new FileWriter(file));

        for (int i = 0; i < data.length; i++) {

            writer.writeNext(data[i]);

        }

        writer.close();

 }

 

 /**

  * 读取csv文件的内容

  * @param fileName

  * @throws Exception

  */

 public static void readFromCSV(String fileName) throws Exception {

  CSVReader reader = new CSVReader(new FileReader("test.csv"));

     /*String [] nextLine;

     while ((nextLine = reader.readNext()) != null) {

         // nextLine[] is an array of values from the line

         System.out.println(nextLine[0] + nextLine[1] + nextLine[2]);

     }*/

  

  List<String[]> myEntries = reader.readAll();//读取所有的内容

  for(int i=0; i<myEntries.size(); i++) { //迭代输出

   String[] temp = myEntries.get(i);

   for(int j=0; j<temp.length; j++)

    System.out.print(temp[j]+'\t');

   System.out.println();

  }

        reader.close();



 }

 

 public static void main(String[] args) { //测试

  String[] header = new String[]{"name", "sex", "age"};

        String[][] data = new String[][]{header, {"Lucy", "F", "22"}, {"Tom", "M", "25"}, {"Lily", "F", "19"}};

        try {

   CSVUtils.writeToCSV(data);

   CSVUtils.readFromCSV("test.csv");

  } catch (Exception e) {

   e.printStackTrace();

  }

  

 }

}

2、可以将sql查询出来的ResultSet直接写入csv文件

public static void queryOnConsole(String account, String sql){

  Connection conn = null;

  Statement stmt = null;

  ResultSet rs = null;

  File tempFile = null;

  try{

   conn = DBUtil.getConn();

   stmt = conn.createStatement();

   rs = stmt.executeQuery(sql);

   tempFile = new File(account+new Date().getTime()+".csv");

         CSVWriter writer = new CSVWriter(new FileWriter(tempFile));

         writer.writeAll(rs, true);

         writer.close();

  }catch(Exception e){

   e.printStackTrace();

  }finally{

   try {

    DBUtil.close(rs, stmt, conn);

   } catch (Exception e) {

    e.printStackTrace();

   }

  }

 }