Java生成CSV文件簡單操做實例

Java生成CSV文件簡單操做實例

 

CSV是逗號分隔文件(Comma Separated Values)的首字母英文縮寫，是一種用來存儲數據的純文本格式，一般用於電子表格或數據庫軟件。在 CSV文件中，數據「欄」以逗號分隔，可容許程序經過讀取文件爲數據從新建立正確的欄結構，並在每次遇到逗號時開始新的一欄。如：

1,張三,男
2,李四,男
3,小紅,女

Java生成CSV文件（建立與導出封裝類）

package com.yph.omp.common.util;

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.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.beanutils.BeanUtils;
import org.junit.Test;

/**
 * Java生成CSV文件
 */
public class CSVUtil {

    /**
     * 生成爲CVS文件
     * 
     * @param exportData
     *            源數據List
     * @param map
     *            csv文件的列表頭map
     * @param outPutPath
     *            文件路徑
     * @param fileName
     *            文件名稱
     * @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();
            }
            // 定義文件名格式並建立
            csvFile = File.createTempFile(fileName, ".csv",
                    new File(outPutPath));
            // UTF-8使正確讀取分隔符","
            csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(
                    new FileOutputStream(csvFile), "GBK"), 1024);
            // 寫入文件頭部
            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();
            // 寫入文件內容
            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();
　　　　　　　　　　　　/*-------------------------------*/　
                    //如下部分根據不一樣業務作出相應的更改
                    StringBuilder sbContext = new StringBuilder("");
                    if (null != BeanUtils.getProperty(row,(String) propertyEntry.getKey())) {
                        if("證件號碼".equals(propertyEntry.getValue())){
                            //避免：身份證號碼 ，讀取時變換爲科學記數 - 解決辦法：加 \t(用Excel打開時，證件號碼超過15位後會自動默認科學記數)
                            sbContext.append(BeanUtils.getProperty(row,(String) propertyEntry.getKey()) + "\t");
                        }else{
                            sbContext.append(BeanUtils.getProperty(row,(String) propertyEntry.getKey()));                            
                        }
                    }
                    csvFileOutputStream.write(sbContext.toString());
　　　　　　　　　　　　/*-------------------------------*/                    
                    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;
    }

    /**
     * 下載文件
     * 
     * @param response
     * @param csvFilePath
     *            文件路徑
     * @param fileName
     *            文件名稱
     * @throws IOException
     */
    public static void exportFile(HttpServletRequest request,
            HttpServletResponse response, String csvFilePath, String fileName)
            throws IOException {
        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/csv;charset=GBK");
        
        response.setHeader("Content-Disposition", "attachment; filename="
                + new String(fileName.getBytes("GB2312"), "ISO8859-1"));
        InputStream in = null;
        try {
            in = new FileInputStream(csvFilePath);
            int len = 0;
            byte[] buffer = new byte[1024];
            OutputStream out = response.getOutputStream();
            while ((len = in.read(buffer)) > 0) {
                out.write(buffer, 0, len);
            }
        } catch (FileNotFoundException e1) {
            System.out.println(e1);
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (Exception e1) {
                    throw new RuntimeException(e1);
                }
            }
        }
    }

    /**
     * 刪除該目錄filePath下的全部文件
     * 
     * @param filePath
     *            文件目錄路徑
     */
    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();
                }
            }
        }
    }

    /**
     * 刪除單個文件
     * 
     * @param filePath
     *            文件目錄路徑
     * @param fileName
     *            文件名稱
     */
    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;
                    }
                }
            }
        }
    }

    @SuppressWarnings({ "unchecked", "rawtypes" })
    @Test
    public void createFileTest() {
        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 = "文件導出";
        File file = CSVUtil.createCSVFile(exportData, map, path, fileName);
        String fileNameNew = file.getName();
        String pathNew = file.getPath();
        System.out.println("文件名稱：" + fileNameNew );
        System.out.println("文件路徑：" + pathNew );
    }
}//注：BeanUtils.getProperty(row,(String) propertyEntry.getKey()) + "\t" ，只爲解決數字格式超過15位後，在Excel中打開展現科學記數問題。