java导出csv格式文件详解编程语言

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 com.alibaba.druid.util.StringUtils; 
/**  
* 文件操作  
*/   
public class CSVUtils {   
/** 
* 功能说明：获取UTF-8编码文本文件开头的BOM签名。 
* BOM(Byte Order Mark)，是UTF编码方案里用于标识编码的标准标记。例：接收者收到以EF BB BF开头的字节流，就知道是UTF-8编码。 
* @return UTF-8编码文本文件开头的BOM签名 
*/ 
public static String getBOM() { 
byte b[] = {(byte)0xEF, (byte)0xBB, (byte)0xBF}; 
return new String(b); 
} 
/**  
* 生成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.mkdirs();   
}   
//定义文件名格式并创建   
csvFile =new File(outPutPath+fileName+".csv"); 
file.createNewFile();   
// UTF-8使正确读取分隔符","   
//如果生产文件乱码，windows下用gbk，linux用UTF-8 
csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(   
csvFile), "UTF-8"), 1024);   
//写入前段字节流，防止乱码 
      csvFileOutputStream.write(getBOM()); 
// 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();   
String str=row!=null?((String)((Map)row).get( propertyEntry.getKey())):"";
 
if(StringUtils.isEmpty(str)){ 
str=""; 
}else{ 
str=str.replaceAll("/"","/"/""); 
if(str.indexOf(",")>=0){ 
str="/""+str+"/""; 
} 
} 
csvFileOutputStream.write(str);   
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;   
}   
/** 
*     生成并下载csv文件 
* @param response 
* @param exportData 
* @param map 
* @param outPutPath 
* @param fileName 
* @throws IOException 
*/ 
@SuppressWarnings("rawtypes") 
public static void exportDataFile(HttpServletResponse response,List exportData, LinkedHashMap map, String outPutPath,String fileName) throws IOException{ 
File csvFile = null;   
BufferedWriter csvFileOutputStream = null;   
try {   
File file = new File(outPutPath);   
if (!file.exists()) {   
file.mkdirs();   
}   
//定义文件名格式并创建   
csvFile =new File(outPutPath+fileName+".csv"); 
if(csvFile.exists()){ 
csvFile.delete();  
} 
csvFile.createNewFile();   
// UTF-8使正确读取分隔符","   
//如果生产文件乱码，windows下用gbk，linux用UTF-8 
csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(csvFile), "UTF-8"), 1024);   
//写入前段字节流，防止乱码 
          csvFileOutputStream.write(getBOM()); 
// 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();   
String str=row!=null?((String)((Map)row).get( propertyEntry.getKey())):""; 
if(StringUtils.isEmpty(str)){ 
str=""; 
}else{ 
str=str.replaceAll("/"","/"/""); 
if(str.indexOf(",")>=0){ 
str="/""+str+"/""; 
} 
} 
csvFileOutputStream.write(str);   
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();   
}   
}   
InputStream in = null;   
try {   
in = new FileInputStream(outPutPath+fileName+".csv");   
int len = 0;   
byte[] buffer = new byte[1024];   
OutputStream out = response.getOutputStream();  
response.reset();  
response.setContentType("application/csv;charset=UTF-8");   
response.setHeader("Content-Disposition","attachment; filename=" + URLEncoder.encode(fileName+".csv", "UTF-8"));   
response.setCharacterEncoding("UTF-8");  
while ((len = in.read(buffer)) > 0) {   
out.write(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF });   
out.write(buffer, 0, len);   
} 
out.close(); 
} catch (FileNotFoundException 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();   
//设置列名 
map.put("1", "第一列名称");   
map.put("2", "第二列名称");   
map.put("3", "第三列名称");   
map.put("4", "第四列名称");   
//这个文件上传到路径，可以配置在数据库从数据库读取，这样方便一些！ 
String path = "E:/";   
//文件名=生产的文件名称+时间戳 
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);   
}   
}