Java 从URL获取文件名
在Java中,给定一个Java 从URL获取文件名,java,file,parsing,url,filenames,Java,File,Parsing,Url,Filenames,在Java中,给定一个Java.net.URL或一个String格式的http://www.example.com/some/path/to/a/file.xml,除去扩展名,获取文件名的最简单方法是什么?因此,在本例中,我正在寻找返回“file”的内容 我可以想出几种方法来做到这一点,但我正在寻找一种易于阅读和简短的方法。这应该可以减少它(我将把错误处理留给您): 我想到了这个: String url = "http://www.example.com/some/path/to/a/file.
Java.net.URL
或一个String
格式的http://www.example.com/some/path/to/a/file.xml
,除去扩展名,获取文件名的最简单方法是什么?因此,在本例中,我正在寻找返回“file”
的内容
我可以想出几种方法来做到这一点,但我正在寻找一种易于阅读和简短的方法。这应该可以减少它(我将把错误处理留给您):
我想到了这个:
String url = "http://www.example.com/some/path/to/a/file.xml";
String file = url.substring(url.lastIndexOf('/')+1, url.lastIndexOf('.'));
导入java.io.*
import java.net.*;
public class ConvertURLToFileName{
public static void main(String[] args)throws IOException{
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Please enter the URL : ");
String str = in.readLine();
try{
URL url = new URL(str);
System.out.println("File : "+ url.getFile());
System.out.println("Converting process Successfully");
}
catch (MalformedURLException me){
System.out.println("Converting process error");
}
我希望这对你有帮助 从字符串创建URL对象。当您第一次拥有URL对象时,有一些方法可以轻松地提取您需要的任何信息片段 我可以强烈推荐Javaalmanac网站,它有大量的例子,但后来它已经移动了。你可能会觉得有趣:
// Create a file object
File file = new File("filename");
// Convert the file object to a URL
URL url = null;
try {
// The file need not exist. It is made into an absolute path
// by prefixing the current working directory
url = file.toURL(); // file:/d:/almanac1.4/java.io/filename
} catch (MalformedURLException e) {
}
// Convert the URL to a file object
file = new File(url.getFile()); // d:/almanac1.4/java.io/filename
// Read the file contents using the URL
try {
// Open an input stream
InputStream is = url.openStream();
// Read from is
is.close();
} catch (IOException e) {
// Could not open the file
}
使用split()重做andy的回答:
公共静态字符串getFileName(URL extUrl){
//URL:“http://photosaaaaa.net/photos-ak-snc1/v315/224/13/659629384/s659629384_752969_4472.jpg"
字符串filename=“”;
//路径:/photos-ak-snc1/v315/224/13/659629384/s659629384_752969_4472.jpg
String path=extUrl.getPath();
//检查前斜杠和/或反斜杠
//注意:**而URL中不支持反斜杠
//大多数浏览器都会用前斜杠自动替换它们
//所以从技术上讲,如果你在解析一个html页面,你可能会遇到
//一个反斜杠,所以我在这里解释它们;
String[]pathContents=path.split(“[\\/]”);
if(pathContents!=null){
int-pathContentsLength=pathContents.length;
System.out.println(“路径内容长度:+pathContentsLength”);
for(int i=0;i1){
int lastPartContentLength=lastPartContents.length;
System.out.println(“最后一部分长度:+lastPartContentLength”);
//文件名可以包含.,因此我们假设之前的所有内容
//最后一个。是名字,在最后一个之后的一切。是
//延伸
字符串名称=”;
for(int i=0;i
这个怎么样:
String filenameWithoutExtension = null;
String fullname = new File(
new URI("http://www.xyz.com/some/deep/path/to/abc.png").getPath()).getName();
int lastIndexOfDot = fullname.lastIndexOf('.');
filenameWithoutExtension = fullname.substring(0,
lastIndexOfDot == -1 ? fullname.length() : lastIndexOfDot);
与其重新发明轮子,不如使用Apache:
下面是在Android中实现这一点的最简单方法。我知道它在Java中不起作用,但它可能会帮助Android应用程序开发人员
import android.webkit.URLUtil;
public String getFileNameFromURL(String url) {
String fileNameWithExtension = null;
String fileNameWithoutExtension = null;
if (URLUtil.isValidUrl(url)) {
fileNameWithExtension = URLUtil.guessFileName(url, null, null);
if (fileNameWithExtension != null && !fileNameWithExtension.isEmpty()) {
String[] f = fileNameWithExtension.split(".");
if (f != null & f.length > 1) {
fileNameWithoutExtension = f[0];
}
}
}
return fileNameWithoutExtension;
}
URL最后可以有参数,这
/**
* Getting file name from url without extension
* @param url string
* @return file name
*/
public static String getFileName(String url) {
String fileName;
int slashIndex = url.lastIndexOf("/");
int qIndex = url.lastIndexOf("?");
if (qIndex > slashIndex) {//if has parameters
fileName = url.substring(slashIndex + 1, qIndex);
} else {
fileName = url.substring(slashIndex + 1);
}
if (fileName.contains(".")) {
fileName = fileName.substring(0, fileName.lastIndexOf("."));
}
return fileName;
}
要返回不带扩展名的文件名和不带参数的,请使用以下命令:
String filenameWithParams = FilenameUtils.getBaseName(urlStr); // may hold params if http://example.com/a?param=yes
return filenameWithParams.split("\\?")[0]; // removing parameters from url if they exist
要返回扩展名不带参数的文件名,请使用以下命令:
/** Parses a URL and extracts the filename from it or returns an empty string (if filename is non existent in the url) <br/>
* This method will work in win/unix formats, will work with mixed case of slashes (forward and backward) <br/>
* This method will remove parameters after the extension
*
* @param urlStr original url string from which we will extract the filename
* @return filename from the url if it exists, or an empty string in all other cases */
private String getFileNameFromUrl(String urlStr) {
String baseName = FilenameUtils.getBaseName(urlStr);
String extension = FilenameUtils.getExtension(urlStr);
try {
extension = extension.split("\\?")[0]; // removing parameters from url if they exist
return baseName.isEmpty() ? "" : baseName + "." + extension;
} catch (NullPointerException npe) {
return "";
}
}
/**解析URL并从中提取文件名或返回空字符串(如果URL中不存在文件名)
*此方法适用于win/unix格式,适用于斜杠的混合情况(向前和向后)
*此方法将在扩展后删除参数
*
*@param urlStr原始url字符串,我们将从中提取文件名
*@从url返回文件名(如果存在),或在所有其他情况下返回空字符串*/
私有字符串getFileNameFromUrl(字符串urlStr){
字符串baseName=FilenameUtils.getBaseName(urlStr);
字符串扩展名=FilenameUtils.getExtension(urlStr);
试一试{
extension=extension.split(“\\?”[0];//从url中删除参数(如果存在)
返回baseName.isEmpty()?“”:baseName+“+扩展名;
}捕获(NullPointerException npe){
返回“”;
}
}
保持简单:
/**
* This function will take an URL as input and return the file name.
* <p>Examples :</p>
* <ul>
* <li>http://example.com/a/b/c/test.txt -> test.txt</li>
* <li>http://example.com/ -> an empty string </li>
* <li>http://example.com/test.txt?param=value -> test.txt</li>
* <li>http://example.com/test.txt#anchor -> test.txt</li>
* </ul>
*
* @param url The input URL
* @return The URL file name
*/
public static String getFileNameFromUrl(URL url) {
String urlString = url.getFile();
return urlString.substring(urlString.lastIndexOf('/') + 1).split("\\?")[0].split("#")[0];
}
/**
*此函数将以URL作为输入并返回文件名。
*示例:
*
*- http://example.com/a/b/c/test.txt ->test.txt
*- http://example.com/ ->空字符串
*- http://example.com/test.txt?param=value ->test.txt
*- http://example.com/test.txt#anchor ->test.txt
*
*
*@param url输入url
*@返回URL文件名
*/
公共静态字符串getFileNameFromUrl(URL URL){
字符串urlString=url.getFile();
返回urlString.substring(urlString.lastIndexOf('/')+1.split(“\\?”)[0]。split(“\\”)[0];
}
获取扩展名为的文件名,不带扩展名,仅扩展名,只有3行:
String urlStr = "http://www.example.com/yourpath/foler/test.png";
String fileName = urlStr.substring(urlStr.lastIndexOf('/')+1, urlStr.length());
String fileNameWithoutExtension = fileName.substring(0, fileName.lastIndexOf('.'));
String fileExtension = urlStr.substring(urlStr.lastIndexOf("."));
Log.i("File Name", fileName);
Log.i("File Name Without Extension", fileNameWithoutExtension);
Log.i("File Extension", fileExtension);
记录结果:
File Name(13656): test.png
File Name Without Extension(13656): test
File Extension(13656): .png
String fileName = Paths.get(strUrl).getFileName().toString();
String fileName = FilenameUtils.getName(strUrl);
UriBuilder buildURI = UriBuilder.fromUri(strUrl);
URI uri = buildURI.build();
String fileName = Paths.get(uri.getPath()).getFileName();
String fileName = strUrl.substring(strUrl.lastIndexOf('/') + 1);
希望它能对您有所帮助。如果您不需要删除文件扩展名,这里有一种方法可以做到这一点,而无需使用容易出错的字符串操作和外部库。适用于Java 1.7+:
import java.net.URI
import java.nio.file.Paths
String url = "http://example.org/file?p=foo&q=bar"
String filename = Paths.get(new URI(url).getPath()).getFileName().toString()
如果只想从java.net.URL获取文件名(不包括任何查询参数),可以使用以下函数:
public static String getFilenameFromURL(URL url) {
return new File(url.getPath().toString()).getName();
}
例如,此输入URL:
"http://example.com/image.png?version=2&modificationDate=1449846324000"
将被转换为此输出字符串:
import java.net.URI
import java.nio.file.Paths
String url = "http://example.org/file?p=foo&q=bar"
String filename = Paths.get(new URI(url).getPath()).getFileName().toString()
String fileName = url.substring(url.lastIndexOf('/') + 1);
public static String getFilenameFromURL(URL url) {
return new File(url.getPath().toString()).getName();
}
"http://example.com/image.png?version=2&modificationDate=1449846324000"
image.png
System.out.println(FilenameUtils.getName("http://www.google.com/.."));
public static String getFilenameFromUrl(String url)
{
if (url == null)
return null;
try
{
// Add a protocol if none found
if (! url.contains("//"))
url = "http://" + url;
URL uri = new URL(url);
String result = FilenameUtils.getName(uri.getPath());
if (result == null || result.isEmpty())
return null;
if (result.contains(".."))
return null;
return result;
}
catch (MalformedURLException e)
{
return null;
}
}
import java.util.Objects;
import java.net.URL;
import org.apache.commons.io.FilenameUtils;
class Main {
public static void main(String[] args) {
validateFilename(null, null);
validateFilename("", null);
validateFilename("www.google.com/../me/you?trex=5#sdf", "you");
validateFilename("www.google.com/../me/you?trex=5 is the num#sdf", "you");
validateFilename("http://www.google.com/test.png?test", "test.png");
validateFilename("http://www.google.com", null);
validateFilename("http://www.google.com#test", null);
validateFilename("http://www.google.com////", null);
validateFilename("www.google.com/..", null);
validateFilename("http://www.google.com/..", null);
validateFilename("http://www.google.com/test", "test");
validateFilename("https://www.google.com/../../test.png", "test.png");
validateFilename("file://www.google.com/test.png", "test.png");
validateFilename("file://www.google.com/../me/you?trex=5", "you");
validateFilename("file://www.google.com/../me/you?trex", "you");
}
private static void validateFilename(String url, String expectedFilename){
String actualFilename = getFilenameFromUrl(url);
System.out.println("");
System.out.println("url:" + url);
System.out.println("filename:" + expectedFilename);
if (! Objects.equals(actualFilename, expectedFilename))
throw new RuntimeException("Problem, actual=" + actualFilename + " and expected=" + expectedFilename + " are not equal");
}
public static String getFilenameFromUrl(String url)
{
if (url == null)
return null;
try
{
// Add a protocol if none found
if (! url.contains("//"))
url = "http://" + url;
URL uri = new URL(url);
String result = FilenameUtils.getName(uri.getPath());
if (result == null || result.isEmpty())
return null;
if (result.contains(".."))
return null;
return result;
}
catch (MalformedURLException e)
{
return null;
}
}
}
import java.util.ArrayList;
import java.util.StringTokenizer;
public class URLName {
public static void main(String args[]){
String url = "http://www.example.com/some/path/to/a/file.xml";
StringTokenizer tokens = new StringTokenizer(url, "/");
ArrayList<String> parts = new ArrayList<>();
while(tokens.hasMoreTokens()){
parts.add(tokens.nextToken());
}
String file = parts.get(parts.size() -1);
int dot = file.indexOf(".");
String fileName = file.substring(0, dot);
System.out.println(fileName);
}
}
new File(uri.getPath).getName
import java.io.File
import java.net.URI
val uri = new URI("http://example.org/file.txt?whatever")
new File(uri.getPath).getName
res18: String = file.txt
new URI("http://example.org/hey/file.txt?whatever").getPath
res20: String = /hey/file.txt
new URI("hdfs:///hey/file.txt").getPath
res21: String = /hey/file.txt
new URI("file:///hey/file.txt").getPath
res22: String = /hey/file.txt
String raw = "http://www.example.com/some/path/to/a/file.xml";
assertEquals("file.xml", Url.parse(raw).path().filename());
raw = "http://www.example.com/files/r%C3%A9sum%C3%A9.pdf";
assertEquals("résumé.pdf", Url.parse(raw).path().filename());
String fileName = Paths.get(strUrl).getFileName().toString();
String fileName = FilenameUtils.getName(strUrl);
UriBuilder buildURI = UriBuilder.fromUri(strUrl);
URI uri = buildURI.build();
String fileName = Paths.get(uri.getPath()).getFileName();
String fileName = strUrl.substring(strUrl.lastIndexOf('/') + 1);
var URL = window.location.pathname; // Gets page name
var page = URL.substring(URL.lastIndexOf('/') + 1);
console.info(page)
List<String> pathSegments = UriComponentsBuilder.fromUriString(url).build().getPathSegments();
String filename = pathSegments.get(pathSegments.size()-1);