java往csv文件中导出百万级数据

package com.hcycom.action;


import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.List;


import jxl.Workbook;
import jxl.write.WritableCellFormat;
import jxl.write.WritableFont;


import com.hcycom.bean.MonthValue;
import com.hcycom.page.page;
import com.hcycom.service.Data;


public class Excel {
//static String url = "/opt/apache-tomcat-6.0.37/file/";
static String url = "D:/opt/apache-tomcat-6.0.37/file/";
Data data;
public void setExcel(String leixing, String name,page pg) {
if ("excel".equals(leixing)) {
wenjian(pg, name);
}
if ("cvs".equals(leixing)||"plCSV".equals(leixing)) {
wenJianCsv(pg, name);
}
if ("txt".equals(leixing)) {
wenJianTxt(pg, name);
}
}
public void setExcelCSV(String name,List<MonthValue> list) {
wenJianPLCsv(list, name);
}
public void wenJianPLCsv(List<MonthValue> list, String name) {         //导出百万条数据name是文件名  list是数据
try {
File file = new File(url + name + ".csv");
if(!file.exists()){
System.out.println("创建文件！！！");
file.createNewFile();
}
writeFileContent(url + name + ".csv", list); //writeFileContent（）这个方法是分批往csv文件中追加数据  ，下面注释掉的是一次性往csv文件中写 数据
/*FileOutputStream stream;// provides file access
OutputStreamWriter writer;// writes to the file
stream = new FileOutputStream(file);
writer = new OutputStreamWriter(stream, "gb2312");
for (int q = 0; q < list.size(); q++) {
writer.write(list.get(q).getAqi());
writer.write(list.get(q).getSO2());
writer.write("\r\n");
}
writer.close();
stream.close();*/
} catch (IOException e1) {
e1.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}


}
public static boolean writeFileContent(String filepath,List<MonthValue> list) throws IOException{
       Boolean bool = false;
       String temp  = "";
       
       FileInputStream fis = null;
       InputStreamReader isr = null;
       BufferedReader br = null;
       FileOutputStream fos  = null;
       PrintWriter pw = null;
       try {
           File file = new File(filepath);//文件路径(包括文件名称)
           //将文件读入输入流
           fis = new FileInputStream(file);
           isr = new InputStreamReader(fis);
           br = new BufferedReader(isr);
           StringBuffer buffer = new StringBuffer();
           int i;
           //文件原有内容
           for(i=0;(temp =br.readLine())!=null;i++){
               buffer.append(temp);
               // 行与行之间的分隔符 相当于“\n”
               buffer = buffer.append(System.getProperty("line.separator"));
           }
           for (int q = 0; q < list.size(); q++) {
            buffer.append(list.get(q).getId()+",");
            buffer.append(list.get(q).getTime_point()+",");
            buffer.append(list.get(q).getAqi()+",");
            buffer.append(list.get(q).getArea()+",");
            buffer.append(list.get(q).getPosition_name()+",");
            buffer.append(list.get(q).getStation_code()+",");
            buffer.append(list.get(q).getSO2()+",");
            buffer.append(list.get(q).getNO2()+",");
            buffer.append(list.get(q).getCO()+",");
            buffer.append(list.get(q).getO3()+",");
            buffer.append(list.get(q).getPM2_5()+",");
            buffer.append(list.get(q).getPM10()+",");
            buffer.append(list.get(q).getPrimary_pollutant().replaceAll(",", "，")+",");  //逗号在csv文件中相当于tab键，每个字段后面加上逗号是分割单元格replaceAll(",", "，")是一个单元格中的数据存在逗号，将英文逗号替换成中文逗号，csv不解析，会直接按字符串处理，这样就不会换单元格了，文本中也会显示逗号，不影响正常的阅读。
            buffer.append(list.get(q).getQuality()+" \r\n");
           }
           fos = new FileOutputStream(file);
           pw = new PrintWriter(fos);
           pw.write(buffer.toString().toCharArray());
           pw.flush();
           bool = true;
       } catch (Exception e) {
           e.printStackTrace();
       }finally {
           //不要忘记关闭
           if (pw != null) {
               pw.close();
           }
           if (fos != null) {
               fos.close();
           }
           if (br != null) {
               br.close();
           }
           if (isr != null) {
               isr.close();
           }
           if (fis != null) {
               fis.close();
           }
       }
       return bool;
   }
public void wenjian(page pg, String name){                                   //这是一次导数EXCLE文件

jxl.write.WritableWorkbook wwb = null;
try {
System.out.println("excel action wenjian  name:"+name);
List<List<String>> list = pg.getListl();
File file = new File(url + ""+name+".xls");
System.out.println("url:"+file.getAbsolutePath()+"\n "+file.toString());
file.delete();
wwb = Workbook.createWorkbook(file);
WritableFont font3 = new WritableFont(
WritableFont.createFont("宋体"), 12, WritableFont.NO_BOLD);
WritableCellFormat f = new WritableCellFormat(font3);
jxl.write.WritableSheet ws = wwb.createSheet("Sheet1", 0);


ws.setColumnView(0, 45); // 设置列的宽度
ws.setColumnView(1, 20); // 设置列的宽度
ws.setColumnView(2, 30); // 设置列的宽度
ws.setColumnView(3, 15); // 设置列的宽度
ws.setColumnView(4, 15); // 设置列的宽度
ws.setColumnView(5, 15); // 设置列的宽度
ws.setColumnView(6, 15); // 设置列的宽度
ws.setColumnView(7, 15); // 设置列的宽度
ws.setColumnView(8, 15); // 设置列的宽度
ws.setColumnView(9, 15); // 设置列的宽度
ws.setColumnView(10, 30); // 设置列的宽度
ws.setColumnView(11, 30); // 设置列的宽度

for (int q = 0; q < list.size(); q++) {
for (int w = 1; w < list.get(q).size(); w++) {
if (!"0".equals(list.get(q).get(w))) {
jxl.write.Label labelC = new jxl.write.Label(w - 1, q,
list.get(q).get(w), f);
ws.addCell(labelC);
} else {
jxl.write.Label labelC = new jxl.write.Label(w - 1, q,
"-", f);
ws.addCell(labelC);
}
}
}
wwb.write();
wwb.close();
} catch (Exception e) {
try {
wwb.close();
} catch (Exception e1) {
e1.printStackTrace();
}
e.printStackTrace();
}
}


public void wenJianCsv(page pg, String name) {  //导出csv文件
try {
System.out.println("pa:"+pg);
File file = new File(url + name + ".csv");
file.createNewFile();
List<List<String>> list = pg.getListl();
FileOutputStream stream;// provides file access
OutputStreamWriter writer;// writes to the file
stream = new FileOutputStream(file);
writer = new OutputStreamWriter(stream, "gb2312");
for (int q = 0; q < list.size(); q++) {
for (int w = 1; w < list.get(q).size(); w++) {
if (w == 1) {
if (!"0".equals(list.get(q).get(w))) {
writer.write(list.get(q).get(w));
} else {
writer.write("-");
}
} else {
if (!"0".equals(list.get(q).get(w))) {
writer.write("," + list.get(q).get(w));
} else {
writer.write("," + "-");
}
}
}
writer.write("\r\n");
}
writer.close();
stream.close();

} catch (IOException e1) {


} catch (Exception e) {
e.printStackTrace();
}


}


public void wenJianTxt(page pg, String name) {                       //导出text文件
try {
File file = new File(url + name + ".txt");
file.createNewFile();
List<List<String>> list = pg.getListl();
FileOutputStream stream;// provides file access
OutputStreamWriter writer;// writes to the file
stream = new FileOutputStream(file);
writer = new OutputStreamWriter(stream, "gb2312");
for (int q = 0; q < list.size(); q++) {
for (int w = 1; w < list.get(q).size(); w++) {
if (w == 1) {
if (!"0".equals(list.get(q).get(w))) {
writer.write(list.get(q).get(w));
} else {
writer.write("-");
}
} else {
if (!"0".equals(list.get(q).get(w))) {
writer.write("," + list.get(q).get(w));
} else {
writer.write("," + "-");
}
}
}
writer.write("\r\n");
}
writer.close();
} catch (IOException e1) {


} catch (Exception e) {
e.printStackTrace();
}


}


public Data getData() {
return data;
}


public void setData(Data data) {
this.data = data;
}


}