java.io.BufferedInputStream in = new java.io.BufferedInputStream(new
java.net.URL(args[1].toString()).openStream());
java.io.FileOutputStream fos = new java.io.FileOutputStream("WorldEdit/schematics/"+args[2].toString());
java.io.BufferedOutputStream bout = new BufferedOutputStream(fos,1024);
byte data[] = new byte[1024];
while(in.read(data,0,1024)>=0)
{
bout.write(data);
}
bout.close();
in.close();
}
我希望这可以从网址下载文件，然后将其放入文件夹中。这个程序将在一个名为“plugins”的文件夹中，我想将下载的文件放在“plugins / WorldEdit / schematic”中。 似乎没有用。有什么建议？
答案 0 :(得分：1)
in.read返回一个数字，表示实际读取的字节数。您忽略了该数字，并假设每次调用都会读取1024个字节。
如果您使用的是Java 7，则可以通过以下方式将URL保存到文件中：
try (InputStream in = new URL(args[1].toString()).openStream()) {
Files.copy(in, Paths.get("WorldEdit", "schematics", args[2].toString()));
}
在Java 6（和5和4）中，您可以使用频道：
FileChannel fileChannel = fos.getChannel();
ReadableByteChannel urlChannel = Channels.newChannel(
new URL(args[1].toString()).openStream());
fileChannel.transferFrom(urlChannel, 0, Long.MAX_VALUE);
答案 1 :(得分：0)
您可以参考以下程序并根据需要进行编辑。 在这个程序中，url是从一个html文件中的表中获取，使用Jsoup解析html文件并下载到我从表中获取的文件夹的不同文件夹...（表有3列文件名，路径，下载链接）。 / p>
转到downloadFile（String urlString）方法，在那里你可以找到你的问题的答案
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author nudanesh
*/
public class URLDownload {
private Document doc;
String url = "", folder, file;
private final File sourceFile;
int i = 1;
int r = 1, c = 1;
int anchorCol = 3;
Library lib;
URLDownload() {
lib = new Library();
sourceFile = new File("Download.html");
try {
doc = Jsoup.parse(sourceFile, "UTF-8");
} catch (IOException ex) {
Logger.getLogger(URLDownload.class.getName()).log(Level.SEVERE, null, ex);
}
//Elements links = doc.select("a[href]");
Elements rows = doc.select("tr");
System.out.println("Size=" + rows.size());
for (Element row : rows) {
Elements cols = row.getElementsByTag("td");
c = 1;
for (Element col : cols) {
System.out.println("Row"+r);
if (c == 1) {
file = col.text();//System.out.println("File in main"+file);
} else if (c == 2) {
folder = col.text();//System.out.println("Folder in main"+folder);
} else {
try {
url = col.getElementsByTag("a").attr("href");
} catch (Exception e) {
System.out.print("-");
}
}
c++;
}
if (!url.equals("")) {
lib.setLocation(file,folder);
lib.downloadFile(url);
}
url = "";
i++;
r++;
}
}
public static void main(String arg[]) {
new URLDownload();
}
}
以下是Library类文件
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.file.Files;
import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author nudanesh
*/
public class Library {
boolean downloaded = false;
Thread t;
int waitTime = 0;
String baseLoc = "";
int size = 1024, ByteWritten = 0;
URL url;
URLConnection uCon = null;
String folderLoc = "", file = "firstFile.csv";
File loc;
private OutputStream outStream;
private InputStream is=null;
private byte[] buf;
private int ByteRead;
private int FolderInUrl = 4;
private boolean rootFolder = true;
private File resultFile;
private FileOutputStream fileResult;
private XSSFWorkbook workbookResult;
private XSSFSheet sheetResult;
private int updateExcelRowNum = -1;
private int updateExcelColNum = -1;
String date;
private int waitLimit = 900000;
Library() {
/*System.out.print(Calendar.getInstance().toString());
Date d=new Date();
String date=d.toString();
System.out.println(date);*/
//t = new Thread(this);
// t.start();
date = new SimpleDateFormat("yyyy_MM_dd_HH_mm_ss").format(Calendar.getInstance().getTime());
System.out.print(date);
baseLoc = date + "/";
WriteDataToExcel();
baseLoc += "Business Reports/";
createRowExcel(updateExcelRowNum);
updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Report Name");
updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Path");
updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Status");
updateExcel();
}
public void setLocation(String a, String b) {
file = a;
file += ".csv";
folderLoc = baseLoc + getFolderPath(b);
// System.out.println("File Name: "+file);
// System.out.println("Folder loc: "+folderLoc);
}
public String getFolderPath(String b) {
String path = "";
try {
System.out.println("path" + b);
path = b;
// path = java.net.URLDecoder.decode(b, "UTF-8");
String p[] = path.split("/");
path = "";
for (int i = FolderInUrl; i < p.length - 1; i++) {
rootFolder = false;
p[i] = removeSpacesAtEnd(p[i]);
path = path + p[i] + "/";
}
} catch (Exception ex) {
Logger.getLogger(Library.class.getName()).log(Level.SEVERE, null, ex);
}
return path;
}
public void downloadFile(String urlString) {
// System.out.println("Started");
try {
url = new URL(urlString);
} catch (MalformedURLException ex) {
Logger.getLogger(Library.class.getName()).log(Level.SEVERE, null, ex);
}
try {
loc = new File(folderLoc);
if (!loc.exists()) {
loc.mkdirs();
}
outStream = new BufferedOutputStream(new FileOutputStream(folderLoc + file));
uCon = url.openConnection();
uCon.setReadTimeout(waitLimit);
is = uCon.getInputStream();
downloaded=true;
buf = new byte[size];
while ((ByteRead = is.read(buf)) != -1) {
System.out.println("while executing" + ByteRead);
outStream.write(buf, 0, ByteRead);
ByteWritten += ByteRead;
}
//System.out.println("Downloaded" + ByteWritten);
resetCounters();
createRowExcel(updateExcelRowNum);
updateRowColExcel(updateExcelRowNum, updateExcelColNum, file);
updateRowColExcel(updateExcelRowNum, updateExcelColNum, folderLoc);
if (ByteWritten < 1000) {
updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Downloaded ");
} else {
updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Downloaded ");
}
updateExcel();
} catch (Exception e) {
System.out.println("error catch" + e);
resetCounters();
createRowExcel(updateExcelRowNum);
updateRowColExcel(updateExcelRowNum, updateExcelColNum, file);
updateRowColExcel(updateExcelRowNum, updateExcelColNum, folderLoc);
updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Rejected the Download after waiting " + (waitLimit / 60000) + " minutes");
updateExcel();
waitTime = 0;
} finally {
try {
System.out.println("Error in streams");
if(downloaded)
is.close();
outStream.close();
downloaded= false;
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void moveToFolder(String reportName, String path) {
try {
File repo = new File(folderLoc + "/" + reportName + ".csv");
path = folderLoc + "/" + path;
File pathFolder = new File(path);
if (!pathFolder.exists()) {
pathFolder.mkdirs();
}
pathFolder = new File(path + reportName + ".csv");
System.out.println("Path=" + pathFolder.getAbsolutePath() + "\nReport path=" + repo.getAbsolutePath());
System.out.println("Source" + repo.getAbsolutePath());
//System.out.println("Status" + repo.renameTo(new File(pathFolder.getAbsolutePath())));
System.out.println("Status" + Files.move(repo.toPath(), new File(pathFolder.getAbsolutePath()).toPath(), REPLACE_EXISTING));
//Files.
} catch (Exception e) {
System.out.println("error while moving" + e);
}
}
public String changeSpecialCharacters(String report) {
report = report.replaceAll(":", "_");
return report;
}
public String removeSpacesAtEnd(String inputPath) {
for (int i = inputPath.length() - 1; i >= 0; i--) {
if (inputPath.charAt(i) != ' ') {
break;
} else {
System.out.println("Before string is" + inputPath);
inputPath = inputPath.substring(0, i);
System.out.println("AFter string is" + inputPath);
}
}
return inputPath;
}
public void WriteDataToExcel() {
try {
// file = new FileInputStream(new File("config.xlsx"));
// File resultFolder = new File("Results");
// if (resultFolder.exists()) {
// deleteDirectory(resultFolder);
// }
// resultFolder.mkdirs();
if (!new File(baseLoc).exists()) {
new File(baseLoc).mkdirs();
}
resultFile = new File(baseLoc + "Reports info " + date + ".xlsx");
System.out.println("Path" + resultFile.getAbsolutePath());
resultFile.createNewFile();
// rFilePath = resultFile.getAbsolutePath();
fileResult = new FileOutputStream(resultFile);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//Get the workbook instance for XLS file
// System.out.println("file success");
XSSFWorkbook workbook = null;
try {
workbookResult = new XSSFWorkbook();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Opening the browser");
//Get first sheet from the workbook
sheetResult = workbookResult.createSheet();
//sheetResult.set
//Get iterator to all the rows in current sheet
//Get iterator to all cells of current row
//ar.add(folderLocation);
// ar.add(firefoxProfileLocation);
}
public void updateExcel() {
try {
//fileResult.close();
fileResult = new FileOutputStream(resultFile);
workbookResult.write(fileResult);
fileResult.close();
} catch (Exception e) {
System.out.println(e);
}
}
public void createRowExcel(int num) {
updateExcelRowNum++;
num = updateExcelRowNum;
sheetResult.createRow(num);
}
public void updateRowColExcel(int rnum, int cnum, String value) {
updateExcelColNum++;
cnum = updateExcelColNum;
sheetResult.getRow(rnum).createCell(cnum);
XSSFCell cell = sheetResult.getRow(rnum).getCell(cnum);
cell.setCellValue(value);
}
public void updateColumn(int rnum, int cnum, String value) {
XSSFCell cell = sheetResult.getRow(rnum).getCell(cnum);
cell.setCellValue(value);
}
public void resetCounters() {
updateExcelColNum = -1;
}
/* @Override
public void run() {
while (true) {
if (true) {
waitTime += 1000;
System.out.println(waitTime);
if (waitTime > waitLimit) {
try {
is.close();
outStream.close();
//downloaded=false;
// cancelDownload=true;
} catch (Exception ex) {
Logger.getLogger(Library.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
try {
Thread.sleep(1000);
} catch (Exception e) {
}
}
}*/
}