java下载本地文件代码 java下载本地文件代码是什么
帮我看看这段java下载代码,文件名为中文时,报错,无法找到指定文件
代码一共6句,前4句没问题,运行下载是ok的,
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最后一句梁友态有点不明白,为什么用BufferedInputStream?这个是读文件的,不知道你后面是如何写的,难道还要把文件读到内存?在向客户端发送出去告孝??这样的话下载GB级文件内存溢出。
BufferedInputStream和BufferedOutputStream 用橡源了之后,一定要flush(),这样也许会解决你的中文下载报错。
我直接用BufferedOutputStream 下载文件成功,前面是用你的,后面如下:
InputStream in = new FileInputStream(file);// 将文件装换成缓冲流
OutputStream out = response.getOutputStream(); // 获取response中得下载对象
BufferedOutputStream bufo = new BufferedOutputStream(out); // 对象转换成字符流
int length = 0; // 读取本地文时,记录本次文件读取内容大小
byte[] buffer = new byte[524288]; // 每次推送 512KB
while ((length = in.read(buffer)) != -1) // 读取本地文件,并在存放在buffer 数组
{
bufo.write(buffer, 0, length);// 预备向客户端推送
bufo.flush();// 清空缓存,并立即推送
}
in.close();
out.close();
bufo.close();
不建议写 response.setContentLength(int); 大并发时,这个容易出问题。
Java中文件下载该怎么写代码求高手指导
if (upfile.exists()) {
bytes = FileUtils.readFileToByteArray(upfile);
response.setContentType("application/x-download");
String agent = request.getHeader("USER-AGENT");//用户代理
// 防穗伏缓止中文厅族文件名乱码
if (null != agent -1 != agent.indexOf("MSIE")) {
String codedfilename = StringUtils.replace(URLEncoder.encode(fileName, "UTF-8"), "+", "%20");
response.setHeader("Content-Disposition"猜模, "attachment;filename=" + codedfilename);
} else if (null != agent -1 != agent.indexOf("Mozilla")) {
String codedfilename = MimeUtility.encodeText(fileName, "UTF-8", "B");
response.setHeader("Content-Disposition", "attachment;filename=" + codedfilename);
} else {
response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
}
response.setContentLength(bytes.length);
response.getOutputStream().write(bytes);
}
java代码怎样将oracle数据库中数据下载本地,为.txt文件或者.excel文件。
第一稿谈个类:
package totabel.action;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JOptionPane;
import topdf.TableToPdf;
import totabel.view.TabelData;
import totabel.xls.ExcelDemo;
public class TableAction implements ActionListener {
TabelData data;
public TableAction(TabelData data) {
this.data = data;
}
public void actionPerformed(ActionEvent e) {
String str = e.getActionCommand();
if ("枣敬雀添加".equals(str)) {
data.addData();
} else if ("导出到Excel".equals(str)) {
ExcelDemo demo = new ExcelDemo();
demo.method(data);
} else if ("删除".equals(str)) {
if (data.getRow() != -1) {
data.delRow();
} else {
JOptionPane.showMessageDialog(null, "请选择要删除的行!");
}
}else if("从Excel导入"凳早.equals(str)){
data.getXlsInfo();
}else if("从Excel导入到数据库".equals(str)){
data.toDb();
}else if("从table导出到pdf".equals(str)){
TableToPdf pdf=new TableToPdf();
pdf.newPage(data);
}else if("计算学分".equals(str)){
data.getXlsInfoToCredit();
}
}
}
第二个类:数据库连接
package totabel.db;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JdbcConnection {
private static JdbcConnection con;
public static JdbcConnection getCon() {
if (con == null) {
con = new JdbcConnection();
}
return con;
}
public Connection getConnection() {
Connection connection=null;
try {
Class.forName("oracle.jdbc.OracleDriver");
String url = "jdbc:oracle:thin:@127.0.0.1:1521:oracle";
String user = "scott";
String password = "tiger";
connection = DriverManager.getConnection(url, user,
password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return connection;
}
// public static void main(String[] args) {
// JdbcConnection connection=new JdbcConnection();
// connection.getConnection("asd", "99");
// }
}
第三个类:主类(入口)
package totabel.db;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JdbcConnection {
private static JdbcConnection con;
public static JdbcConnection getCon() {
if (con == null) {
con = new JdbcConnection();
}
return con;
}
public Connection getConnection() {
Connection connection=null;
try {
Class.forName("oracle.jdbc.OracleDriver");
String url = "jdbc:oracle:thin:@127.0.0.1:1521:oracle";
String user = "scott";
String password = "tiger";
connection = DriverManager.getConnection(url, user,
password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return connection;
}
// public static void main(String[] args) {
// JdbcConnection connection=new JdbcConnection();
// connection.getConnection("asd", "99");
// }
}
第四个类:
package totabel.xls;
import java.io.File;
import java.io.IOException;
import java.util.Vector;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.swing.JOptionPane;
import totabel.view.TabelData;
import jxl.Cell;
import jxl.Sheet;
import jxl.Workbook;
import jxl.read.biff.BiffException;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;
import jxl.write.biff.RowsExceededException;
public class ExcelDemo {
/**
*
* @param args
*/
private Vector title = new Vector();
private Vector[] array;
// public static void main(String[] args) {
// ExcelDemo demo = new ExcelDemo();
// demo.getXlsInfo();
//
// }
public void method(TabelData table) {
int row = table.getRowSize();
int column = table.getColumnSize();
WritableWorkbook book = null;
Vector title = table.setTitle();
Object[] str = title.toArray();
try {
book = Workbook.createWorkbook(new File("test.xls"));
WritableSheet sheet = book.createSheet("成绩表", 0);
for (int i = 0; i str.length; i++) {
sheet.addCell(new Label(i, 0, (String) str[i]));
}
for (int i = 1; i row + 1; i++) {
for (int j = 1; j column + 1; j++) {
sheet.addCell(new Label(j - 1, i, table.getTableInfo(i - 1,
j - 1)));
}
}
book.write();
JOptionPane.showMessageDialog(null, "导出完成!");
} catch (IOException e) {
e.printStackTrace();
} catch (RowsExceededException e) {
e.printStackTrace();
} catch (WriteException e) {
e.printStackTrace();
} finally {
try {
book.close();
} catch (WriteException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 输出Excel的数据到表单
*
* @return
*/
public Vector getXlsInfo() {
Vector v = new Vector();
jxl.Workbook rwb = null;
int index = 0;
try {
rwb = jxl.Workbook.getWorkbook(new File("test.xls"));
Sheet[] sheet = rwb.getSheets();
for (int i = 0; i sheet.length; i++) {
int rs = sheet[i].getRows();
array = new Vector[rs - 1];
for (int j = 1; j rs; j++) {
Cell[] cell = sheet[i].getRow(j);
Vector info = new Vector();
for (int k = 0; k cell.length; k++) {
info.add(cell[k].getContents());
}
array[index] = info;
index++;
v.add(info);
}
Cell[] titleCell = sheet[i].getRow(0);
for (int j = 0; j titleCell.length; j++) {
title.add(titleCell[j].getContents());
}
}
} catch (BiffException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
rwb.close();
}
return v;
}
public Vector getXlsInfoToCredit() {
Vector v = new Vector();
jxl.Workbook rwb = null;
try {
rwb = jxl.Workbook.getWorkbook(new File("d:/test/信科0821(南迁).xls"));
Sheet[] sheet = rwb.getSheets();
for (int i = 0; i sheet.length; i++) {
int rs = sheet[i].getRows();
array = new Vector[rs - 1];
for (int j = 1; j rs; j++) {
Cell[] cell = sheet[i].getRow(j);
Vector info = new Vector();
for (int k = 0; k cell.length; k++) {
// if(){
Pattern p = Pattern点抗 pile("[0-9]{1,}");
Matcher m = p.matcher(cell[k].getContents());
if (m.matches()) {
int score = Integer.valueOf(cell[k].getContents());
float result = getScore(score);
info.add(result);
} else {
info.add(cell[k].getContents());
}
}
v.add(info);
}
Cell[] titleCell = sheet[i].getRow(0);
for (int j = 0; j titleCell.length; j++) {
title.add(titleCell[j].getContents());
}
}
} catch (BiffException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
rwb.close();
}
return v;
}
public float getScore(int n) {
float score = n;
if (n 60) {
score = 0;
return score;
} else {
if (n = 60 n = 63) {
score = (float) 1.0;
} else if (n = 64 n = 67) {
score = (float) 1.3;
} else if (n = 68 n = 71) {
score = (float) 1.7;
} else if (n = 72 n = 75) {
score = (float) 2.0;
} else if (n = 76 n = 79) {
score = (float) 2.3;
} else if (n = 80 n = 83) {
score = (float) 2.7;
} else if (n = 84 n = 87) {
score = (float) 3.0;
} else if (n = 88 n = 91) {
score = (float) 3.3;
} else if (n = 92 n = 95) {
score = (float) 3.7;
} else if (n = 96 n = 100) {
score = (float) 4.0;
}
return score;
}
}
public Vector getTitle() {
// getXlsInfo();
return title;
}
public Vector[] getArray() {
getXlsInfo();
return array;
}
}
因为时间问题就没有再写了,上面是我以前做的,不懂就q我
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