標簽： url uri file path

File to URI:

File file = ...;

URI uri = file.toURI();

File to URL:

File file = ...;

URL url = file.toURI().URL();

URL to File:

URL url = ...;

File file = new Path(url.getPath()).toFile();

URI to URL:

URI uri = ...;

URL url = uri.toURL();

URL to URI:

URL url = ...;

URI uri = url.toURI();

一般情況下采用上述方式都可以安全的使用.

但是, 當處理本地路徑且有空格,或者特殊字符,比如漢字等. 路徑在相互的轉換過程中, 可能會出現轉換的無效字符錯誤異常.

所以, 可以使用Eclipse提供的工具類org.eclipse.core.runtime.URIUtil (插件: org.eclipse.equinox.simpleconfigurator)來進行轉換.

URL URI File Path 轉換(原創)

比如URL to File:

URL url = ...;

File file = URIUtil.toFile(URIUtil.toURI(url));

當URL, URI直接互相轉換時,也可以使用該URIUtil工具類.

toURI

toURL

還有一個工具類,就是org.eclipse.core.runtime.FileLocator(插件: org.eclipse.equinox.common) 也可以對URL進行File的格式化. 比如toFileURL方法.

附源碼:

package org.eclipse.equinox.internal.simpleconfigurator.utils;

import java.io.File;

import java.net.*;

public class URIUtil {

private static final String SCHEME_FILE = "file"; //$NON-NLS-1$

private static final String UNC_PREFIX = "//"; //$NON-NLS-1$

public static URI append(URI base, String extension) {

try {

String path = base.getPath();

if (path == null)

return appendOpaque(base, extension);

//if the base is already a directory then resolve will just do the right thing

if (path.endsWith("/")) {//$NON-NLS-1$

URI result = base.resolve(extension);

//Fix UNC paths that are incorrectly normalized by URI#resolve (see Java bug 4723726)

String resultPath = result.getPath();

if (path.startsWith(UNC_PREFIX) && (resultPath == null || !resultPath.startsWith(UNC_PREFIX)))

result = new URI(result.getScheme(), "///" + result.getSchemeSpecificPart(), result.getFragment()); //$NON-NLS-1$

return result;

}

path = path + "/" + extension; //$NON-NLS-1$

return new URI(base.getScheme(), base.getUserInfo(), base.getHost(), base.getPort(), path, base.getQuery(), base.getFragment());

} catch (URISyntaxException e) {

//shouldn't happen because we started from a valid URI

throw new RuntimeException(e);

}

}

private static URI appendOpaque(URI base, String extension) throws URISyntaxException {

String ssp = base.getSchemeSpecificPart();

if (ssp.endsWith("/")) //$NON-NLS-1$

ssp += extension;

else

ssp = ssp + "/" + extension; //$NON-NLS-1$

return new URI(base.getScheme(), ssp, base.getFragment());

}

public static URI fromString(String uriString) throws URISyntaxException {

int colon = uriString.indexOf(':');

int hash = uriString.lastIndexOf('#');

boolean noHash = hash < 0;

if (noHash)

hash = uriString.length();

String scheme = colon < 0 ? null : uriString.substring(0, colon);

String ssp = uriString.substring(colon + 1, hash);

String fragment = noHash ? null : uriString.substring(hash + 1);

//use java.io.File for constructing file: URIs

if (scheme != null && scheme.equals(SCHEME_FILE)) {

File file = new File(uriString.substring(5));

if (file.isAbsolute())

return file.toURI();

scheme = null;

if (File.separatorChar != '/')

ssp = ssp.replace(File.separatorChar, '/');

}

return new URI(scheme, ssp, fragment);

}

public static boolean sameURI(URI url1, URI url2) {

if (url1 == url2)

return true;

if (url1 == null || url2 == null)

return false;

if (url1.equals(url2))

return true;

if (url1.isAbsolute() != url2.isAbsolute())

return false;

// check if we have two local file references that are case variants

File file1 = toFile(url1);

return file1 == null ? false : file1.equals(toFile(url2));

}

public static File toFile(URI uri) {

try {

if (!SCHEME_FILE.equalsIgnoreCase(uri.getScheme()))

return null;

//assume all illegal characters have been properly encoded, so use URI class to unencode

return new File(uri);

} catch (IllegalArgumentException e) {

//File constructor does not support non-hierarchical URI

String path = uri.getPath();

//path is null for non-hierarchical URI such as file:c:/tmp

if (path == null)

path = uri.getSchemeSpecificPart();

return new File(path);

}

}

public static String toUnencodedString(URI uri) {

StringBuffer result = new StringBuffer();

String scheme = uri.getScheme();

if (scheme != null)

result.append(scheme).append(':');

//there is always a ssp

result.append(uri.getSchemeSpecificPart());

String fragment = uri.getFragment();

if (fragment != null)

result.append('#').append(fragment);

return result.toString();

}

public static URI toURI(URL url) throws URISyntaxException {

//URL behaves differently across platforms so for file: URLs we parse from string form

if (SCHEME_FILE.equals(url.getProtocol())) {

String pathString = url.toExternalForm().substring(5);

//ensure there is a leading slash to handle common malformed URLs such as file:c:/tmp

if (pathString.indexOf('/') != 0)

pathString = '/' + pathString;

else if (pathString.startsWith(UNC_PREFIX) && !pathString.startsWith(UNC_PREFIX, 2)) {

//URL encodes UNC path with two slashes, but URI uses four (see bug 207103)

pathString = UNC_PREFIX + pathString;

}

return new URI(SCHEME_FILE, null, pathString, null);

}

try {

return new URI(url.toExternalForm());

} catch (URISyntaxException e) {

//try multi-argument URI constructor to perform encoding

return new URI(url.getProtocol(), url.getUserInfo(), url.getHost(), url.getPort(), url.getPath(), url.getQuery(), url.getRef());

}

}

public static URL toURL(URI uri) throws MalformedURLException {

return new URL(uri.toString());

}

}