Java生成CSV文件实例详解

本文实例主要讲述了java生成csv文件的方法，具体实现步骤如下：

1、新建csvutils.java文件：

package com.saicfc.pmpf.internal.manage.utils;

import java.io.bufferedwriter;
import java.io.file;
import java.io.fileinputstream;
import java.io.filenotfoundexception;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.io.inputstream;
import java.io.outputstream;
import java.io.outputstreamwriter;
import java.net.urlencoder;
import java.util.arraylist;
import java.util.iterator;
import java.util.linkedhashmap;
import java.util.list;
import java.util.map;

import javax.servlet.http.httpservletresponse;

import org.apache.commons.beanutils.beanutils;

/**
 * 文件操作
 */
public class csvutils {

  /**
   * 生成为cvs文件 
   * @param exportdata
   *       源数据list
   * @param map
   *       csv文件的列表头map
   * @param outputpath
   *       文件路径
   * @param filename
   *       文件名称
   * @return
   */
  @suppresswarnings("rawtypes")
  public static file createcsvfile(list exportdata, linkedhashmap map, string outputpath,
                   string filename) {
    file csvfile = null;
    bufferedwriter csvfileoutputstream = null;
    try {
      file file = new file(outputpath);
      if (!file.exists()) {
        file.mkdir();
      }
      //定义文件名格式并创建
      csvfile = file.createtempfile(filename, ".csv", new file(outputpath));
      system.out.println("csvfile：" + csvfile);
      // utf-8使正确读取分隔符"," 
      csvfileoutputstream = new bufferedwriter(new outputstreamwriter(new fileoutputstream(
        csvfile), "utf-8"), 1024);
      system.out.println("csvfileoutputstream：" + csvfileoutputstream);
      // 写入文件头部 
      for (iterator propertyiterator = map.entryset().iterator(); propertyiterator.hasnext();) {
        java.util.map.entry propertyentry = (java.util.map.entry) propertyiterator.next();
        csvfileoutputstream
          .write(""" + (string) propertyentry.getvalue() != null ? (string) propertyentry
            .getvalue() : "" + """);
        if (propertyiterator.hasnext()) {
          csvfileoutputstream.write(",");
        }
      }
      csvfileoutputstream.newline();
      // 写入文件内容 
      for (iterator iterator = exportdata.iterator(); iterator.hasnext();) {
        object row = (object) iterator.next();
        for (iterator propertyiterator = map.entryset().iterator(); propertyiterator
          .hasnext();) {
          java.util.map.entry propertyentry = (java.util.map.entry) propertyiterator
            .next();
          csvfileoutputstream.write((string) beanutils.getproperty(row,
            (string) propertyentry.getkey()));
          if (propertyiterator.hasnext()) {
            csvfileoutputstream.write(",");
          }
        }
        if (iterator.hasnext()) {
          csvfileoutputstream.newline();
        }
      }
      csvfileoutputstream.flush();
    } catch (exception e) {
      e.printstacktrace();
    } finally {
      try {
        csvfileoutputstream.close();
      } catch (ioexception e) {
        e.printstacktrace();
      }
    }
    return csvfile;
  }

  /**
   * 下载文件
   * @param response
   * @param csvfilepath
   *       文件路径
   * @param filename
   *       文件名称
   * @throws ioexception
   */
  public static void exportfile(httpservletresponse response, string csvfilepath, string filename)
                                                  throws ioexception {
    response.setcontenttype("application/csv;charset=utf-8");
    response.setheader("content-disposition",
      "attachment; filename=" + urlencoder.encode(filename, "utf-8"));

    inputstream in = null;
    try {
      in = new fileinputstream(csvfilepath);
      int len = 0;
      byte[] buffer = new byte[1024];
      response.setcharacterencoding("utf-8");
      outputstream out = response.getoutputstream();
      while ((len = in.read(buffer)) > 0) {
        out.write(new byte[] { (byte) 0xef, (byte) 0xbb, (byte) 0xbf });
        out.write(buffer, 0, len);
      }
    } catch (filenotfoundexception e) {
      system.out.println(e);
    } finally {
      if (in != null) {
        try {
          in.close();
        } catch (exception e) {
          throw new runtimeexception(e);
        }
      }
    }
  }

  /**
   * 删除该目录filepath下的所有文件
   * @param filepath
   *      文件目录路径
   */
  public static void deletefiles(string filepath) {
    file file = new file(filepath);
    if (file.exists()) {
      file[] files = file.listfiles();
      for (int i = 0; i < files.length; i++) {
        if (files[i].isfile()) {
          files[i].delete();
        }
      }
    }
  }

  /**
   * 删除单个文件
   * @param filepath
   *     文件目录路径
   * @param filename
   *     文件名称
   */
  public static void deletefile(string filepath, string filename) {
    file file = new file(filepath);
    if (file.exists()) {
      file[] files = file.listfiles();
      for (int i = 0; i < files.length; i++) {
        if (files[i].isfile()) {
          if (files[i].getname().equals(filename)) {
            files[i].delete();
            return;
          }
        }
      }
    }
  }

  /**
   * 测试数据
   * @param args
   */
  @suppresswarnings({ "rawtypes", "unchecked" })
  public static void main(string[] args) {
    list exportdata = new arraylist<map>();
    map row1 = new linkedhashmap<string, string>();
    row1.put("1", "11");
    row1.put("2", "12");
    row1.put("3", "13");
    row1.put("4", "14");
    exportdata.add(row1);
    row1 = new linkedhashmap<string, string>();
    row1.put("1", "21");
    row1.put("2", "22");
    row1.put("3", "23");
    row1.put("4", "24");
    exportdata.add(row1);
    linkedhashmap map = new linkedhashmap();
    map.put("1", "第一列");
    map.put("2", "第二列");
    map.put("3", "第三列");
    map.put("4", "第四列");

    string path = "c:/export/";
    string filename = "文件导出";
    file file = csvutils.createcsvfile(exportdata, map, path, filename);
    string filename2 = file.getname();
    system.out.println("文件名称：" + filename2);
  }
}

2、调用createcsvfile方法生成csv文件

string name = "银行退款数据";
list exportdata = new arraylist();
linkedhashmap datammap = null;
for (iterator iterator = refundlist.iterator(); iterator.hasnext();) {
   hashmap map = (hashmap) iterator.next();
   datammap = new linkedhashmap();
   datammap.put("1", map.get("merorderid"));
   datammap.put("2",dateutil.convertdatetostring("yyyymmdd", (date) map.get("ordertime")));
   bigdecimal amount = (bigdecimal) map.get("amount");
   string amountstring = amount.divide(new bigdecimal(10)).toplainstring();
   datammap.put("3", amountstring);
   datammap.put("4", map.get("remark") != null ? map.get("remark") : "");
   exportdata.add(datammap);
}
 linkedhashmap map = new linkedhashmap();
 map.put("1", "订单号");
 map.put("2", "支付日期");
 map.put("3", "退货现金金额（整数金额 单位：分）");
 map.put("4", "退货原因");
 file file = csvutils.createcsvfile(exportdata, map, filepath, name);//生成csv文件
 filename = file.getname();
 csvutils.exportfile(response, filepath + filename, filename);//下载生成的csv文件