opencsv方式读取csv文件，详解，示例

1.opencsv官网：http://opencsv.sourceforge.net/

   jar包：opencsv-2.3.jar

   下载地址：http://sourceforge.net/projects/opencsv/files/latest/download

2.读取CSV文件

package com.szaisino.common.opencsv;import java.io.File;import java.io.FileReader;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import au.com.bytecode.opencsv.CSVReader;/** *  * <b>所属模块：</b>发票处理系统.公用模块<br/>  * <b>类名称：</b>ReadCSVFile<br/>  * <b>类描述：</b> 读取CSV文件   <br/>  * <b>版本：</b>V1.0<br/>  * <b>创建人：</b><a href="mailto:[e-mail]">牧羊仒</a><br/>   * <b>创建时间：</b>2016年4月20日 下午5:09:27<br/> */public class ReadCSVFile {private static final String ADDRESS_FILE = "d:\\addresses.csv";    /**     *      * 读取csv中的内容     *      * @return     * @throws IOException      * @return List<String[]>     * @exception 异常描述     * @see     */public static List<String[]> readCSVFile(File file, int startRow, String characters) throws IOException{    List<String[]> strArrayList = new ArrayList<String[]>();        CSVReader reader = null;    if (",".equalsIgnoreCase(characters)){    reader = new CSVReader(new FileReader(file));    } else {    //带分隔符    reader = new CSVReader(new FileReader(file),characters.toCharArray()[0]);    }            String[] nextLine;        int i = 1;        while ((nextLine = reader.readNext()) != null) {//          System.out.println("Name: [" + nextLine[0] + "]\nAddress: [" + nextLine[1] + "]\nEmail: [" + nextLine[2] + "]");                    if (i>=startRow)        strArrayList.add(nextLine);                    i++;        }                return strArrayList;    }        /**     *      * 读取csv中的内容     * Map key:csvFileFirstRow csv文件，表头标题；     *     key:csvFileContent  csv文件，内容(除去表头内容)     *      * @param file       csv文件对象     * @param startRow   开始行     * @param characters 分隔符     * @return     * @throws IOException      * @return Map<String,List<String[]>>     * @exception 异常描述     * @see     */public static Map<String, List<String[]>> readCSVFileWithMap(File file, int startRow, String characters) throws IOException{List<String[]> csvFileFirstRowArrayList = new ArrayList<String[]>();    List<String[]> strArrayList = new ArrayList<String[]>();        CSVReader reader = null;    if (",".equalsIgnoreCase(characters)){    reader = new CSVReader(new FileReader(file));    } else {    //带分隔符    reader = new CSVReader(new FileReader(file),characters.toCharArray()[0]);    }                String[] nextLine;        int i = 1;        while ((nextLine = reader.readNext()) != null) {//          System.out.println("Name: [" + nextLine[0] + "]\nAddress: [" + nextLine[1] + "]\nEmail: [" + nextLine[2] + "]");                    if (i>=startRow)        strArrayList.add(nextLine);        else         csvFileFirstRowArrayList.add(nextLine);                    i++;        }                Map<String, List<String[]>> map = new HashMap<String, List<String[]>>();        map.put("csvFileFirstRow", csvFileFirstRowArrayList);        map.put("csvFileContent", strArrayList);        return map;    }}

3.写入CSV文件

package com.szaisino.common.opencsv;import java.io.File;import java.io.FileWriter;import java.io.IOException;import java.text.SimpleDateFormat;import java.util.Date;import java.util.List;import au.com.bytecode.opencsv.CSVWriter;/** *  * <b>所属模块：</b>发票处理系统.公用模块<br/>  * <b>类名称：</b>WriteCSVFile<br/>  * <b>类描述：</b> 写入CSV文件   <br/>  * <b>版本：</b>V1.0<br/>  * <b>创建人：</b><a href="mailto:[e-mail]">牧羊仒</a><br/>   * <b>创建时间：</b>2016年4月20日 下午5:14:30<br/> */public class WriteCSVFile {/** *  * 向CSV写数据   *  * @param writeFilePath  文件路径 * @param strArrayList   文件内容 * @return void * @throws IOException  * @exception 异常描述 * @see */public static void writeCSVFile(String writeFilePath, List<String[]> strArrayList, String characters) throws IOException{//判断文件是否存在，如果存在，先删除File file = new File(writeFilePath);if (file.exists())file.delete();    CSVWriter writer = null;  //    try {    if (",".equalsIgnoreCase(characters)){    //初始化CSVWriter        writer = new CSVWriter(new FileWriter(file));      } else{    //初始化CSVWriter，带分隔符        writer = new CSVWriter(new FileWriter(file),characters.toCharArray()[0]);      }//    } catch (IOException e) {  //        e.printStackTrace();  //    }        writer.writeAll(strArrayList);    //    try {writer.close();//} catch (IOException e) {//e.printStackTrace();//}}/** *  * 向CSV写数据   *  * @param writeFilePath * @param strArrayList * @param strArrayList  * @return void * @throws IOException  * @exception 异常描述 * @see */public static void writeCSVFile(String writeFilePath, List<String[]> csvFileFirstRowList, List<String[]> contentArrayList, String characters) throws IOException{//处理反斜杠if (!writeFilePath.endsWith("\\") && !writeFilePath.endsWith("/")){ //如果不是以\\结尾，则加上\\writeFilePath = writeFilePath+"\\\\";}//文件名String fileName = writeFilePath+new SimpleDateFormat("yyyyMMdd").format(new Date())+".csv"; //yyyyMMddHHmm//判断文件是否存在，如果存在，先删除File file = new File(fileName);if (file.exists())file.delete();    CSVWriter writer = null;      if (",".equalsIgnoreCase(characters)){    //初始化CSVWriter        writer = new CSVWriter(new FileWriter(file));      } else{    //初始化CSVWriter，带分隔符        writer = new CSVWriter(new FileWriter(file),characters.toCharArray()[0]);      }        //csv表头数据+表体数据    csvFileFirstRowList.addAll(contentArrayList);    writer.writeAll(csvFileFirstRowList);        //关闭流    writer.close();}}

导出的csv文件如下（默认是带双引号的）：

"手机号码","姓名","订单号","发票代码","发票号","发票日期","发票金额""000000000","牧羊仒","0121342","030012111","13244","20170217","100"

CSVWriter 的构造函数有好几个，这里示例试用的是含有3个参数的构造，
第一个是指定Writer(不同情况下我们可能使用不同的writer)，
第二个参数是分隔符通常是分号或者逗号
第三个参数即是告知CSVWriter不要使用任何的引号来引数据，默认是双引号“”

导出不带双引号的csv文件：

public static void writeCSVFile(String writeFilePath, List<String[]> csvFileFirstRowList, List<String[]> contentArrayList, String characters) throws IOException{//处理反斜杠if (!writeFilePath.endsWith("\\") && !writeFilePath.endsWith("/")){ //如果不是以\\结尾，则加上\\writeFilePath = writeFilePath+"\\\\";}//文件名String fileName = writeFilePath+new SimpleDateFormat("yyyyMMdd").format(new Date())+".csv"; //yyyyMMddHHmm//判断文件是否存在，如果存在，先删除File file = new File(fileName);if (file.exists())file.delete();  //初始化CSVWriter    CSVWriter writer = new CSVWriter(new FileWriter(file), ',', CSVWriter.NO_QUOTE_CHARACTER);        //csv表头数据+表体数据    csvFileFirstRowList.addAll(contentArrayList);    writer.writeAll(csvFileFirstRowList);        //关闭流    writer.close();}