JAVA導出Excel、TXT、批量導出ZIP
目標
實現JAVA導出Excel、TXT、批量導出ZIP文件。
知識點
1.字節流與字符流
區別:
讀寫單位:顧名思義,字節流以字節(byte)爲讀寫單位,而字符流以字符爲讀寫單位,根據碼錶映射字符,一次可能讀入多個字符。
處理對象:字節流可以處理所有類型的數據(包括圖片等),而字符流只能處理字符類型的純文本數據。
字節流:一次寫入或讀出8位二進制。
字符流:一次寫入或讀出至少8位二進制。不同的字符所佔的字節是不同的。
ASCII碼:
一個英文字母(不分大小寫)佔一個字節的空間,一箇中文漢字佔兩個字節的空間。一個二進制數字序列,在計算機中作爲一個數字單元,一般爲8位二進制數,換算爲十進制。最小值0,最大值255。如一個ASCII碼就是一個字節。
UTF-8編碼:
一個英文字符等於一個字節,一箇中文(含繁體)等於三個字節。
Unicode編碼:
一個英文等於兩個字節,一箇中文(含繁體)等於兩個字節。
2.簡述頁面導出文件的邏輯(直接導出TXT,一般讀寫流(stream)的時候,數據是先被讀到了內存中,再把數據寫到文件中)
- 設置reponse響應
- 獲取輸出流response.getOutputStream();
- 將文件內容以字節流形式寫入
- 清空緩存區數據,把緩衝區的數據強行輸出 flush()
- 關閉輸出流
/* 導出txt文件
* @author
* @param response
* @param text 要導出的字符串
* @return
*/
public void exportTxt(HttpServletResponse response,String text){
response.setCharacterEncoding("utf-8");
//設置響應的內容類型
response.setContentType("text/plain");
//設置文件的名稱和格式
response.addHeader("Content-Disposition","attachment;filename="
+ new String(("文件中文名稱").getBytes("gb2312"),"iso8859-1")//設置名稱格式,沒有這個中文名稱無法顯示
+ ".txt");
BufferedOutputStream buff = null;
ServletOutputStream outStr = null;
try {
outStr = response.getOutputStream();
buff = new BufferedOutputStream(outStr);
buff.write(text.getBytes("UTF-8"));
buff.flush();
buff.close();
} catch (Exception e) {
//LOGGER.error("導出文件文件出錯:{}",e);
} finally {try {
buff.close();
outStr.close();
} catch (Exception e) {
//LOGGER.error("關閉流對象出錯 e:{}",e);
}
}
}
【java頁面導出TXT】
SSM框架下導出TXT,參考【SSM框架, 導出TXT】
3. 一些類
- BufferedInputStream: 輸入緩衝流:先從磁盤中將要讀取的內容放入到內存中,再一次性從內存中取出來,避免了讀一段取一段;(
未使用
)構造需基於outputStream
public void readFileWithBufferedStream(String srcPath, int size) {
InputStream inputStream = null;
BufferedInputStream bufferedInputStream = null;
StringBuffer sb = new StringBuffer();
try {
inputStream = new FileInputStream(srcPath);
bufferedInputStream = new BufferedInputStream(inputStream);
byte[] byteArr = new byte[size];
int len = 0;
while ((len = bufferedInputStream.read(byteArr)) != -1) {
sb.append(new String(byteArr), 0, len);
}
System.out.println(sb);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
- BufferedOutputStream: 輸出緩衝流:先將要輸出的內容放入到內存中,再一次性全都輸出。
構造需基於outputStream
public void writeFileWithBufferedStream(String content, String destPath) {
OutputStream outputStream = null;
BufferedOutputStream bufferedOutputStream = null;
try {
// 下面的語句中,如果destPath中的目錄不存在,不會自動創建目錄,因此,建議使用下面的代碼
// outputStream = new FileOutputStream(destPath);
// 前提是輸出的路徑是"/"而不是"\\"
File tmp = new File(destPath.substring(0, destPath.lastIndexOf("/")));
if(!tmp.exists()){
tmp.mkdirs();
}
outputStream = new FileOutputStream(destPath);
bufferedOutputStream = new BufferedOutputStream(outputStream);
byte[] byteArr = content.getBytes();
bufferedOutputStream.write(byteArr);
bufferedOutputStream.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
- XSSFWorkbook類 excel2007文檔對象;構造基於inputStream
//後面用到
public static void exportExcelFromContent(HttpServletResponse response, String data, String savefileName)
throws Exception{
BASE64Decoder base64Decoder = new BASE64Decoder();
byte[] b =base64Decoder.decodeBuffer(data); //data爲經過base64加密的字符,所以解碼爲字節流
InputStream inputStream = new ByteArrayInputStream(b);
Workbook wb = null;
String headStr = "attachment; filename=" + new String((savefileName).getBytes("gb2312"),"iso8859-1");
//製表平臺只支持xlsx
headStr +='.xlsx';
wb= new XSSFWorkbook(inputStream);
//輸出流
OutputStream out = null;
try{
response.setContentType("APPLICATION/OCTET-STREAM");
response.setHeader("Content-Disposition", headStr);
out = response.getOutputStream();
wb.write(out);
}
catch (IOException e){
logger.error("導出Excel文件出錯!", e);
} finally{
if(out != null){
out.close();
}
}
}
- ZipOutputStream
ZipInputStream “壓縮文件輸入流”,用於讀取磁盤上的壓縮文件
ZipOutputStream “壓縮文件輸出流”,用於將程序中的壓縮流寫出到磁盤上。
通常需要使用ZipFile ZipInputStream/ZipOutputStream ZipEntry級File完成解壓縮操作
//壓縮 文件
public static void doCompress(ZipOutputStream zos, File file, String baseDir) throws Exception {
if (file.isDirectory()) {
// 遞歸循環,只壓縮其中所有文件
File[] files = file.listFiles();
for (int i = 0; i < files.length; i++) {
doCompress(zos, files[i], baseDir);
}
} else {
// 進行文件壓縮的操作
byte[] buff = new byte[DEFAULT_BUFF_SIZE];
InputStream in = new FileInputStream(file);
zos.putNextEntry(new ZipEntry(baseDir + File.separator + file.getName()));
int len;
while ((len = in.read(buff,0 ,DEFAULT_BUFF_SIZE)) != -1) {
zos.write(buff, 0, len);
}
in.close();
}
}
單個及批量導出EXcel文件
@RequestMapping(value ="/exportReport.json")
public void exportFile(HttpServletResponse response, String action , String filenameList )throws Exception{
try {
JSONArray jsonArray = JSONArray.fromObject(filenameList);
List<Map<String, String>> resultMap = JSONArray.toList(jsonArray, new HashMap<String, String>(), new JsonConfig());
if(resultMap.size() == 1){
//單個導出
String reportName = resultMap.get(0).get("reportName");
String coop_branch_no = String.valueOf(resultMap.get(0).get("coop_branch_no"));
String reportId = StringUtils.equals("0",coop_branch_no)? String.valueOf(resultMap.get(0).get("report_id")) : String.valueOf(resultMap.get(0).get("report_id"))+"[" + coop_branch_no + "]" ;
String branchNo = String.valueOf(resultMap.get(0).get("branch_no"));
//報送導出頁面 period_date=0L
String reportContent = bizReportService.getReportContent(reportId, branchNo, coop_branch_no,0L); //獲取EXcel文件內容,reportContent爲base64編碼後的字符
FileUtils.exportExcelFromContent(response, reportContent, StringUtils.equals("0",coop_branch_no)? reportName:reportName+"[" + coop_branch_no + "]");
}else if(resultMap.size() > 1){
//批量導出
String reportName,coop_branch_no,branchNo,reportId,filePath = "";
response.reset();
//用於輸出新生成文件名 keys: filePath fileName
List<Map<String, String>> filePaths = new ArrayList<>();
for(Map<String,String> file : resultMap){
Map<String,String> zipFileOutput = new HashMap<>();
if(file != null){
//組合成完整的文件路徑
reportName = String.valueOf(file.get("reportName"));
String newFileName = StringUtils.equals("0",coop_branch_no)? reportName + ".xlsx" :reportName+"[" + coop_branch_no + "]" + ".xlsx";
zipFileOutput.put("reportId",reportId);
zipFileOutput.put("branchNo",branchNo);
zipFileOutput.put("coop_branch_no",coop_branch_no);
zipFileOutput.put("fileName",newFileName);
filePaths.add(zipFileOutput);
}
}
//創建壓縮文件需要的空的zip包
Date date = new Date();
SimpleDateFormat dateFormat= new SimpleDateFormat("yyyy-MM-dd HH-mm-ss");
String zipName = dateFormat.format(date) + ".zip";
String zipFilePath = filePath+zipName;
//壓縮文件
File zip = new File(zipFilePath);
if (!zip.exists()){
zip.createNewFile();
}
//創建zip文件輸出流
ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(zip));
this.zipFileFromContent(filePaths, zos);
zos.close();
//設置編碼字符
response.setContentType("text/html; charset=UTF-8");
//設置內容類型爲下載類型
response.setContentType("application/octet-stream");
//設置下載的壓縮文件名稱
response.setHeader("Content-disposition", "attachment;filename="+zipName);
//創建頁面返回方式爲輸出流,會自動彈出下載框
OutputStream out = response.getOutputStream();
//將打包後的文件使用緩衝流輸出;這種方式與直接 outputStream輸出文件內容的字節流,不太一樣;這裏先讀後寫
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(zipFilePath));
byte[] buff = new byte[bis.available()];
bis.read(buff);
bis.close();
//輸出數據文件
out.write(buff);
//釋放緩存
out.flush();
//關閉輸出流
out.close();
new File(zipFilePath).delete();
}
} catch (Exception e) {
logger.error("導出excel文件出錯:"+e.getMessage());
}
}
//私有方法
private String zipFileFromContent(List<Map<String, String>> filePaths, ZipOutputStream zos) throws IOException {
//循環讀取集合,獲取每一個報表信息以獲取報表內容
for(Map<String,String> filePath : filePaths){
String reportContent = bizReportService.getReportContent(filePath.get("reportId"), filePath.get("branchNo"),
filePath.get("coop_branch_no"),0L);
BASE64Decoder base64Decoder = new BASE64Decoder();
byte[] b =base64Decoder.decodeBuffer(reportContent);
InputStream in = new ByteArrayInputStream(b);
//創建輸入流讀取文件
BufferedInputStream bis = new BufferedInputStream(in) ;
//將文件寫入zip內,即將文件進行打包
zos.putNextEntry(new ZipEntry(filePath.get("fileName")));
//寫入文件的方法,同上
int size = 0;
//設置讀取數據緩存大小
byte[] buffer = new byte[1024];
while ((size = bis.read(buffer)) > 0) {
zos.write(buffer, 0, size);
}
//關閉輸入輸出流
zos.closeEntry();
bis.close();
}
return null;
}
批量導出TXT文件
@RequestMapping(value ="/exportTXT.json")
public void exportTXT(String txtnameList, HttpServletResponse resp)throws Exception {
// 清空輸出流
resp.reset();
try{
JSONArray jsonArray = JSONArray.fromObject(txtnameList);
List<Map<String, String>> resultMap = JSONArray.toList(jsonArray, new HashMap<String, String>(), new JsonConfig());
if(resultMap.size() == 1){
String reportId = resultMap.get(0).get("report_id");
String branchNo = resultMap.get(0).get("branch_no");
String reportName = resultMap.get(0).get("reportName");
String coopBranchNo = resultMap.get(0).get("coop_branch_no");
String periodDate = "0";
String reportData = uraReportExportService.exportTXTFile(reportId, branchNo, coopBranchNo, periodDate);
if ("fail".equals(reportData)) {
logger.error("獲取TXT內容失敗");
} else {
resp.setCharacterEncoding("UTF-8");
// 設定輸出文件頭
resp.setHeader("Content-disposition", "attachment; filename=" + new String((reportName).getBytes("gb2312"),"iso8859-1") + ".TXT");
// 定義輸出類型
resp.setContentType("text/plain");
//輸出流
BufferedOutputStream buff = null;
OutputStream out = resp.getOutputStream();
buff = new BufferedOutputStream(out);
buff.write(reportData.getBytes("utf-8"));
buff.flush();
buff.close();
logger.info("TXT文件導出成功");
}
} else if(resultMap.size() > 1){
//批量導出TXT
String reportName,coopBranchNo,branchNo,reportId,filePath = "";
resp.reset();
List<Map<String, String>> filePaths = new ArrayList<>();
for(Map<String,String> file : resultMap){
Map<String,String> zipFileOutput = new HashMap<>();
if(file != null){
//組合成完整的文件路徑
reportName = String.valueOf(file.get("reportName"));
String newFileName = StringUtils.equals("0",coopBranchNo)? reportName + ".TXT" :reportName+"[" + coopBranchNo + "]" + ".TXT";
zipFileOutput.put("reportId",reportId);
zipFileOutput.put("branchNo",branchNo);
zipFileOutput.put("coop_branch_no",coopBranchNo);
zipFileOutput.put("fileName",newFileName);
filePaths.add(zipFileOutput);
}
}
//創建壓縮文件需要的空的zip包
String zipBasePath= filePath ;
Date date = new Date();
SimpleDateFormat dateFormat= new SimpleDateFormat("yyyy-MM-dd HH-mm-ss");
String zipName = dateFormat.format(date) + ".zip";
String zipFilePath = filePath+zipName;
//壓縮文件
File zip = new File(zipFilePath);
if (!zip.exists()){
zip.createNewFile();
}
//創建zip文件輸出流
ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(zip));
this.zipFileFromTXTContent(filePaths, zos);
zos.close();
//設置編碼字符
resp.setContentType("text/html; charset=UTF-8");
//設置內容類型爲下載類型
resp.setContentType("application/octet-stream");
//設置下載的壓縮文件名稱
resp.setHeader("Content-disposition", "attachment;filename="+zipName);
//創建頁面返回方式爲輸出流,會自動彈出下載框
OutputStream out = resp.getOutputStream();
//將打包後的文件使用緩衝流輸出
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(zipFilePath));
byte[] buff = new byte[bis.available()];
bis.read(buff);
bis.close();
//輸出數據文件
out.write(buff);
//釋放緩存
out.flush();
//關閉輸出流
out.close();
new File(zipFilePath).delete();
}
} catch (Exception e){
logger.error("TXT導出失敗",e.toString());
}
}