java 导出csv格式（支持list的实体类）

         做的网页项目，要导出pdf使用itext工具，要是excel就使用jxl的jar包，导出csv格式的话，就可以使用如下工具类，参考的博主是http://blog.csdn.net/xuxu198899223/article/details/38079885?utm_source=tuicool&utm_medium=referral，他支持传入的数据是map的形式的，实际在项目中不太常用，一般都是实体类的Arraylist形式，这样支持扩展，如下我在他的基础上修改的代码（保留他原来的代码）：

     1.实体类：

/** *  * @author ALLONE * */public class BankWageMonth {private String id;//private String number;//public String getId() {return id;}public void setId(String id) {this.id = id;}public String getNumber() {return number;}public void setNumber(String number) {this.number = number;}}

    2.工具类，导出csv格式：

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.lang.reflect.Method;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 jxl.write.Label;import org.apache.commons.beanutils.BeanUtils;/** * 文件操作 *  * @author qiulinhe * @version 2016年12月23日14:21:39 */public class CsvUtil {/** * 生成为CVS文件 *  * @param exportData *            源数据List * @param fileds * @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, String[] fileds,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), "GBK"), 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 ? new String(((String) propertyEntry.getValue()).getBytes("GBK"), "GBK") : "");if (propertyIterator.hasNext()) {csvFileOutputStream.write(",");}System.out.println(new String(((String) propertyEntry.getValue()).getBytes("GBK"), "GBK"));}csvFileOutputStream.write("\r\n");// 写入文件内容,// ============ //第一种格式：Arraylist<实体类>填充实体类的基本信息==================for (int j = 0; exportData != null && !exportData.isEmpty()&& j < exportData.size(); j++) {BankWageMonth t = (BankWageMonth) exportData.get(j);Class clazz = t.getClass();String[] contents = new String[fileds.length];for (int i = 0; fileds != null && i < fileds.length; i++) {String filedName = toUpperCaseFirstOne(fileds[i]);Method method = clazz.getMethod(filedName);method.setAccessible(true);Object obj = method.invoke(t);String str = String.valueOf(obj);if (str == null || str.equals("null"))str = "";contents[i] = str;}for (int n = 0; n < contents.length; n++) {// 将生成的单元格添加到工作表中csvFileOutputStream.write(contents[n]);csvFileOutputStream.write(",");}csvFileOutputStream.write("\r\n");}// ============ //第二种格式：Arraylist<map>填充实体类的基本信息==================// 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()) != null ? (String)// propertyEntry// .getKey() : ""));// if (propertyIterator.hasNext()) {// csvFileOutputStream.write(",");// }// }// if (iterator.hasNext()) {// csvFileOutputStream.write("\r\n");// }// }// =================================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=GBK");response.setHeader("Content-Disposition", "attachment;  filename="+ new String(fileName.getBytes("GBK"), "ISO8859-1"));// URLEncoder.encode(fileName, "GBK")InputStream in = null;try {in = new FileInputStream(csvFilePath);int len = 0;byte[] buffer = new byte[1024];response.setCharacterEncoding("GBK");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) {// 获取农商银行的数据:true代表是农商// =======改成list的格式，支持（Arraylist传入实体类的形式），改造的方法============ArrayList<BankWageMonth> bankWageList = new ArrayList<BankWageMonth>();BankWageMonth bankWage = new BankWageMonth();bankWage.setId("123");bankWage.setNumber("2016rz0001");BankWageMonth bankWage2 = new BankWageMonth();bankWage2.setId("124");bankWage2.setNumber("2016rz0002");bankWageList.add(bankWage);bankWageList.add(bankWage2);// =======改成list的格式(支持map的形式），原作者的方法============// 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 = "D://export//";String fileName = "文件导出";String fileds[] = new String[] { "id", "number" };// 设置列英文名（也就是实体类里面对应的列名）File file = CsvUtil.createCSVFile(bankWageList, fileds, map, path,fileName);String fileName2 = file.getName();System.out.println("文件名称：" + fileName2);}/** * 将第一个字母转换为大写字母并和get拼合成方法 *  * @param origin * @return */private static String toUpperCaseFirstOne(String origin) {StringBuffer sb = new StringBuffer(origin);sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));sb.insert(0, "get");return sb.toString();}}