数据库导出CSV格式，并压缩成ZIP的形式导出

因为Excel导出会导致内存溢出，所以以CSV格式导出。

以下实现的功能：从数据读取数，以CSV格式导出，并压缩成ZIP，让用户下载。下面是一次导出的文件是6万条，超过6万条的，自动生成第二个文件。这个是客户的要求，一次导出一个文件其实更方便。曾经尝试过，下载百万千万条数据生成CSV格式，是不会内存溢出的。

不足之处有两个地方，CSV格式下载到本地，用户提出，一定要可以自己选路径，那没办法，本来都已经下载到本地了，只好再压缩一遍让客户自己选了。

第二，本模块不是通用的。做了一个通用的模块，但是因为每次取多少个字段不确定，只是在while里加for循环来实现，所以效率几何倍数的递减。

实现之前要导入两三个jar文件：ant.jar，commons-compress-1.3.jar，opencsv-1.8.jar。

示例下载地址：

import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;
import oracle.jdbc.OracleTypes;
import au.com.bytecode.opencsv.CSVWriter;


/**
 * @title 
 * @description Action
 * @copyright Copyright (c) 2012
 * @author painarthur
 * @version 1.0
 */

public class Ncp_fhyDAO {

public void exportCsv(HttpServletResponse response,int resultCountAll,String path,String csvExportIllustrate,
		int page, int pageSize,String p_cswjg_dm,String p_csssq
		,String p_cHymx_dm,String p_cHY_Level,String p_cPX_ZD,String p_cPX_SJ) 
			throws DataAccessException {
	JDBCDataSource jDBCDataSource = JDBCDataSource.getJDBCDataSource();
	PreparedStatement preparedStatement = null;
	ResultSet result = null;
	Connection conn = null;
	File tempFile = null;
	CSVWriter writer = null;
	ZipOutputStream zos = null;
	FileInputStream fis = null;
	int t1 = (int) System.currentTimeMillis();
	try {
		conn = jDBCDataSource.getConnection();
		CallableStatement proc = conn
				.prepareCall("{call sjcq.BP_**_FHY_HS(?,?,?,?,?,?,?)}");
		proc.setString(1, p_csssq);
		proc.setString(2, p_cswjg_dm);
		proc.setString(3, p_cHymx_dm);
		proc.setString(4, p_cHY_Level);
		proc.setString(5, p_cPX_ZD);
		proc.setString(6, p_cPX_SJ);
		proc.registerOutParameter(7, OracleTypes.VARCHAR);
		proc.execute();
		String queryStr = proc.getString(7); //存储过程输出SQL语句
		preparedStatement = conn.prepareStatement(queryStr);
		result = preparedStatement.executeQuery(queryStr);	
		
		String fileName = "农产品**查询";
		String fileExtension = ".csv";
		int bs = -1;//倍数
		int exportMax = 60000;  //一次导出6万条数据
		int temp = 1;
		String executeStr = "";
		String fullName = "";
		//FileWriter w = null;
		//if(resultCountAll/exportMax>=1){
			bs = resultCountAll/exportMax;
		//}
		while(bs>=0){
			String [] includeHeaders = {"行业代码","行业名称","户数"};  //定义导出CSV文件头文件
			if(resultCountAll>=(exportMax*temp)){  //一次导出6万条数据，多出的部分，生成第二个6万条数据文件
				executeStr = "SELECT *  FROM (select rownum myNum,TempAA.* FROM (" + queryStr + ")TempAA ) where myNum>="
							+ (temp-1)*exportMax + " and TempAA.myNum<=" + exportMax*temp;
				tempFile = new File(path+fileName+temp+fileExtension);
				fullName = path+fileName+temp+fileExtension;   //指定导出的文件目录
			}else if(resultCountAll%exportMax!=0){  //剩下的不足6万条的导出最后一个文件
				executeStr = "SELECT *  FROM (select rownum myNum,TempAA.* FROM (" + queryStr + ")TempAA ) where myNum>="
					+ (temp-1)*exportMax + " and myNum<=" + resultCountAll;
				fullName = path+fileName+temp+fileExtension;  
			}
			preparedStatement = conn.prepareStatement(executeStr);
			result = preparedStatement.executeQuery(executeStr);   
			writer = new CSVWriter(new FileWriter(fullName));   //new一个CSV文件
			writer.writeNext(includeHeaders);
			while (result.next()) {
				String[] data = new String[]{
						StringUtil.isoToGbk(result.getString("HY_DM")),//行业代码
					     StringUtil.isoToGbk(result.getString("HY_MC")),//行业名称
					     StringUtil.isoToGbk(result.getString("HS"))//户数
				};
				writer.writeNext(data);
			}
			writer.flush();
			writer.close();
			if (result != null) {
				result.close();
				result = null;
			}
			if (preparedStatement != null) {
				preparedStatement.close();
				preparedStatement = null;
			}
			bs-=1;
			temp+=1;
		}
		tempFile = null;
               //如果不以压缩包的形式导出，下面的代码就完全没有必要要了。上面的部分，系统会以CSV格式导出到本地。
                response.setContentType("application/zip");
		response.reset();
		response.setCharacterEncoding("GBK");
		response.setHeader("Content-Disposition","attachment; filename=" + new String(fileName.getBytes("GBK"),"ISO8859-1")+".zip" );
		//文件压缩
		int leng=0;
		zos = new ZipOutputStream(response.getOutputStream());   
		File delFile = null;
		for(int i = temp-1;i>0;i--){
			fis = new FileInputStream(path+fileName+ i + ".csv");
			ZipEntry z1 = new ZipEntry(fileName+i+".csv");
			zos.setComment(csvExportIllustrate);
			zos.putNextEntry(z1);
			byte[] b = new byte[1024];
			while((leng = fis.read(b))!=-1){
				zos.write(b,0,leng);
			}
			zos.setEncoding("GBK");
			fis.close();
		}
		zos.close();
		//文件删除
		for(int i = temp-1;i>0;i--){
			delFile = new File(path+fileName+ i + ".csv");
			delFile.delete();
		}
	} catch (Exception e) {
		throw new DataAccessException(e);
	} finally {
		// 释放资源
		try {
			if(zos!=null){
				try {
					zos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
				zos = null;
			}
			if(fis!=null){
				try {
					fis.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
				fis = null;
			}
			
			if(writer!=null){
				try {
					writer.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
				writer = null;
			}
			if (result != null) {
				result.close();
				result = null;
			}
			if (preparedStatement != null) {
				preparedStatement.close();
				preparedStatement = null;
			}
		} catch (SQLException e1) {
			throw new DataAccessException(e1);
		}
	}
}

}

以下是通用的，如果有更好的实现方法或功能，请提出建议。

import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import javax.servlet.http.HttpServletResponse;
import oracle.jdbc.OracleTypes;
import au.com.bytecode.opencsv.CSVWriter;


public class ExportCsvToZip {
	private String zipSm = "超过6万条数据后，以CSV格式导出。";//导出zip文件说明
	/*
	 * add by li_dyue
	 * date: 20120324
	 * function:compose csv files and export zip
	 * 
	 *  csvFileName 暂时生成的csv文件名称
	 *  exportZipName 要导出的zip文件名称
	 *  includeHeaders csv文件的列表的第一列，例如：纳税人识别号、纳税人名称、税务机关等
	 *  dataPO 给csv文件赋值的PO们
	 *  querysql 需要查询的sql语句
	 *  exportMax 定义一次最多导出多少条csv文件
	 *  resultNumber 一共需要导出多少条记录
	 *  
	 *  文件给生成到本地，查出一条就往文件里写一条，
	 *  如果要把这些数据都放到内存中再压缩，那么在大数据量的时候，一定会发生内存溢出问题。
	 *  
	 */
	
	public void exportZip(HttpServletResponse response, String csvFileName, String exportZipName,
			String[] includeHeaders, String[] dataPO, String querysql, int resultNumber)
			throws DataAccessException {
		
		JDBCDataSource jDBCDataSource = JDBCDataSource.getJDBCDataSource();
		List rs_list = new ArrayList();
		PageListData pageListData = new PageListData();
		PreparedStatement preparedStatement = null;
		ResultSet result = null;
		Connection conn = null;
		File tempFile = null;
		CSVWriter writer = null;
		ZipOutputStream zos = null;
		FileInputStream fis = null;
		//path: 先在服务器上生成csv文件的路径
		StringBuffer path = new StringBuffer();
		path.append("c:/lee/");
		String fileExtension = ".csv";
		String c = "";
		int countAll = 0;
		int bs = -1;//倍数
		int exportMax = 60000;
		int temp = 1;
		String executeStr = "";
		StringBuffer bf = new StringBuffer();
		int t1 = (int) System.currentTimeMillis();
		String[] data = new String[dataPO.length];
		try {
			conn = jDBCDataSource.getConnection();
			
			countAll = resultNumber;
			if(countAll/exportMax>=1){
				bs = countAll/exportMax;
			}
			while(bs>=0){
				if(countAll>=(exportMax*temp)){
					executeStr = "SELECT *  FROM (select rownum myNum,TempAA.* FROM (" + querysql + ")TempAA ) where myNum>="
								+ (temp-1)*exportMax + " and myNum<=" + exportMax*temp;
					preparedStatement = conn.prepareStatement(executeStr);
					result = preparedStatement.executeQuery(executeStr);
					tempFile = new File(path+csvFileName+temp+fileExtension);
					System.out.println("csvFileName:"+csvFileName+temp+fileExtension);
					writer = new CSVWriter(new FileWriter(tempFile));
					writer.writeNext(includeHeaders);
										
					while (result.next()) {
						//String[] data = new String[dataPO.length];
                                                //!!!  此处的for循环，严重影响了导出的效率，暂无好的解决方案
                                                for(int i=0;i<dataPO.length;i++){
							data[i] =  StringUtil.isoToGbk(result.getString(dataPO[i]));
						}
						writer.writeNext(data);
					}
					writer.close();
					if (result != null) {
						result.close();
						result = null;
					}
					if (preparedStatement != null) {
						preparedStatement.close();
						preparedStatement = null;
					}
				}else if(countAll%exportMax!=0){
					executeStr = "SELECT *  FROM (select rownum myNum,aa.* FROM (" + querysql + ")aa ) where myNum>="
					+ (temp-1)*exportMax + " and myNum<=" + countAll;
					preparedStatement = conn.prepareStatement(executeStr);
					result = preparedStatement.executeQuery(executeStr);
					tempFile = new File(path+csvFileName+temp+fileExtension);
					System.out.println("csvFileName:"+csvFileName+temp+fileExtension);
					writer = new CSVWriter(new FileWriter(tempFile));
					writer.writeNext(includeHeaders);
					while (result.next()) {
						
						for(int i=0;i<dataPO.length;i++){
							data[i] =  StringUtil.isoToGbk(result.getString(dataPO[i]));
						}
						writer.writeNext(data);
					}
					writer.close();
					if (result != null) {
						result.close();
						result = null;
					}
					if (preparedStatement != null) {
						preparedStatement.close();
						preparedStatement = null;
					}
				}
				bs-=1;
				temp+=1;
			}
			int t2 = (int) System.currentTimeMillis();
			System.out.println((t2-t1)/3600);
			
			File file = new File("c:/lee/c.zip");
			String outputFile = csvFileName+temp + ".csv";
			
			response.setContentType("application/zip");
			response.reset();
			exportZipName = "aa";
			response.setHeader("Content-Disposition",
					"attachment; filename=\"" + "c.zip" + "\"" );
			response.setCharacterEncoding("UTF-8");
			int leng=0;
			zos = new ZipOutputStream(response.getOutputStream());   

			for(int i = temp-1;i>0;i--){
				//System.out.println("=:"+path+csvFileName+i+fileExtension);
				fis = new FileInputStream(path+csvFileName+i+fileExtension);
				ZipEntry z1 = new ZipEntry(csvFileName+temp+fileExtension);
				zos.putNextEntry(z1);
				byte[] b = new byte[1024];
				while((leng = fis.read(b))!=-1){
					zos.write(b,0,leng);
				}
			}
			zos.close();
			fis.close();
			
		} catch (Exception e) {
			throw new DataAccessException(e);
		} finally {
			// 释放资源
			try {
				if(response.getOutputStream() != null)
					response.getOutputStream().close();
			} catch (IOException e2) {
				e2.printStackTrace();
			}
			try {
				if(zos!=null){
					try {
						zos.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
					zos = null;
				}
				if(fis!=null){
					try {
						fis.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
					fis = null;
				}
				
				if(writer!=null){
					try {
						writer.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
					writer = null;
				}
				if (result != null) {
					result.close();
					result = null;
				}
				if (preparedStatement != null) {
					preparedStatement.close();
					preparedStatement = null;
				}
				
			} catch (SQLException e1) {
				throw new DataAccessException(e1);
			}
		}
	
		
	}
	public void deleteCsvFiles(String path,String fileName){
		
	}
	
	//如果导出内容小于6000条，那么导出excel格式；如果导出内容大于6000条，那么导出cvs格式，然后再压缩。
	public boolean ExportToExcel(int resultCountAll){
		boolean exportExcel = false;
		if(resultCountAll<6000){
			exportExcel = true;
		}
		return exportExcel;
	}
	public String getZipSm() {
		return zipSm;
	}
	public void setZipSm(String zipSm) {
		this.zipSm = zipSm;
	}
}