org.apache.juneau.UriResolver Maven / Gradle / Ivy
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package org.apache.juneau;
import static org.apache.juneau.UriRelativity.*;
import static org.apache.juneau.UriResolution.*;
import static org.apache.juneau.internal.StringUtils.*;
import java.io.*;
import java.net.*;
import org.apache.juneau.internal.*;
/**
* Class used to create absolute and root-relative URIs based on your current URI 'location' and rules about how to
* make such resolutions.
*
*
* Combines a {@link UriContext} instance with rules for resolution ({@link UriResolution} and relativity
* ({@link UriRelativity}) to define simple {@link #resolve(Object)} and {@link #append(Appendable, Object)} methods.
*
*
* Three special protocols are used to represent context-root-relative, servlet-relative, and request-path-relative
* URIs:
* "context:/" , "servlet:/" , and "request:/" .
*
*
* The following list shows the protocols of URLs that can be resolved with this class:
*
* "foo://foo" - Absolute URI.
* "/foo" - Root-relative URI.
* "/" - Root URI.
* "context:/foo" - Context-root-relative URI.
* "context:/" - Context-root URI.
* "servlet:/foo" - Servlet-path-relative URI.
* "servlet:/" - Servlet-path URI.
* "request:/foo" - Request-path-relative URI.
* "request:/" - Request-path URI.
* "foo" - Path-info-relative URI.
* "" - Path-info URI.
*
*/
public class UriResolver {
private final UriResolution resolution;
private final UriRelativity relativity;
private final String authority, contextRoot, servletPath, pathInfo, parentPath;
/**
* Constructor.
*
* @param resolution Rule on how URIs should be resolved.
* @param relativity Rule on what relative URIs are relative to.
* @param uriContext Current URI context (i.e. the current URI 'location').
*/
public UriResolver(UriResolution resolution, UriRelativity relativity, UriContext uriContext) {
this.resolution = resolution;
this.relativity = relativity;
this.authority = uriContext.authority;
this.contextRoot = uriContext.contextRoot;
this.servletPath = uriContext.servletPath;
this.pathInfo = uriContext.pathInfo;
this.parentPath = uriContext.parentPath;
}
/**
* Converts the specified URI to absolute form based on values in this context.
*
* @param uri
* The URI to convert to absolute form.
* Can be any of the following:
*
* - {@link java.net.URI}
*
- {@link java.net.URL}
*
- {@link CharSequence}
*
* URI can be any of the following forms:
*
* "foo://foo" - Absolute URI.
* "/foo" - Root-relative URI.
* "/" - Root URI.
* "context:/foo" - Context-root-relative URI.
* "context:/" - Context-root URI.
* "servlet:/foo" - Servlet-path-relative URI.
* "servlet:/" - Servlet-path URI.
* "request:/foo" - Request-path-relative URI.
* "request:/" - Request-path URI.
* "foo" - Path-info-relative URI.
* "" - Path-info URI.
*
* @return The converted URI.
*/
public String resolve(Object uri) {
return resolve(uri, resolution);
}
private String resolve(Object uri, UriResolution res) {
String s = StringUtils.toString(uri);
if (isAbsoluteUri(s))
return hasDotSegments(s) && res != NONE ? normalize(s) : s;
if (res == ROOT_RELATIVE && startsWith(s, '/'))
return hasDotSegments(s) ? normalize(s) : s;
if (res == NONE && ! isSpecialUri(s))
return s;
return append(new StringBuilder(), s).toString();
}
/**
* Relativizes a URI.
*
*
* Similar to {@link URI#relativize(URI)}, except supports special protocols (e.g. "servlet:/" ) for both
* the relativeTo and uri parameters.
*
*
* For example, to relativize a URI to its servlet-relative form:
*
* // relativeUri == "path/foo"
* String relativeUri = resolver.relativize("servlet:/" , "/context/servlet/path/foo" );
*
*
* @param relativeTo The URI to relativize against.
* @param uri The URI to relativize.
* @return The relativized URI.
*/
public String relativize(Object relativeTo, Object uri) {
String r = resolve(relativeTo, ABSOLUTE);
String s = resolve(uri, ABSOLUTE);
return URI.create(r).relativize(URI.create(s)).toString();
}
/**
* Same as {@link #resolve(Object)} except appends result to the specified appendable.
*
* @param a The appendable to append the URL to.
* @param o The URI to convert to absolute form.
* @return The same appendable passed in.
*/
public Appendable append(Appendable a, Object o) {
try {
String uri = StringUtils.toString(o);
uri = nullIfEmpty(uri);
boolean needsNormalize = hasDotSegments(uri) && resolution != null;
// Absolute paths are not changed.
if (isAbsoluteUri(uri))
return a.append(needsNormalize ? normalize(uri) : uri);
if (resolution == NONE && ! isSpecialUri(uri))
return a.append(emptyIfNull(uri));
if (resolution == ROOT_RELATIVE && startsWith(uri, '/'))
return a.append(needsNormalize ? normalize(uri) : uri);
Appendable a2 = needsNormalize ? new StringBuilder() : a;
// Root-relative path
if (startsWith(uri, '/')) {
if (authority != null)
a2.append(authority);
if (uri.length() != 1)
a2.append(uri);
else if (authority == null)
a2.append('/');
}
// Context-relative path
else if (uri != null && uri.startsWith("context:/")) {
if (resolution == ABSOLUTE && authority != null)
a2.append(authority);
if (contextRoot != null)
a2.append('/').append(contextRoot);
if (uri.length() > 9)
a2.append('/').append(uri.substring(9));
else if (contextRoot == null && (authority == null || resolution != ABSOLUTE))
a2.append('/');
}
// Resource-relative path
else if (uri != null && uri.startsWith("servlet:/")) {
if (resolution == ABSOLUTE && authority != null)
a2.append(authority);
if (contextRoot != null)
a2.append('/').append(contextRoot);
if (servletPath != null)
a2.append('/').append(servletPath);
if (uri.length() > 9)
a2.append('/').append(uri.substring(9));
else if (servletPath == null && contextRoot == null && (authority == null || resolution != ABSOLUTE))
a2.append('/');
}
// Request-relative path
else if (uri != null && uri.startsWith("request:/")) {
if (resolution == ABSOLUTE && authority != null)
a2.append(authority);
if (contextRoot != null)
a2.append('/').append(contextRoot);
if (servletPath != null)
a2.append('/').append(servletPath);
if (pathInfo != null)
a2.append('/').append(pathInfo);
if (uri.length() > 9)
a2.append('/').append(uri.substring(9));
else if (servletPath == null && contextRoot == null && pathInfo == null && (authority == null || resolution != ABSOLUTE))
a2.append('/');
}
// Relative path
else {
if (resolution == ABSOLUTE && authority != null)
a2.append(authority);
if (contextRoot != null)
a2.append('/').append(contextRoot);
if (servletPath != null)
a2.append('/').append(servletPath);
if (relativity == RESOURCE && uri != null)
a2.append('/').append(uri);
else if (relativity == PATH_INFO) {
if (uri == null) {
if (pathInfo != null)
a2.append('/').append(pathInfo);
} else {
if (parentPath != null)
a2.append('/').append(parentPath);
a2.append('/').append(uri);
}
}
else if (uri == null && contextRoot == null && servletPath == null && (authority == null || resolution != ABSOLUTE))
a2.append('/');
}
if (needsNormalize)
a.append(normalize(a2.toString()));
return a;
} catch (IOException e) {
throw new RuntimeException(e);
}
}
private static boolean isSpecialUri(String s) {
if (s == null || s.length() == 0)
return false;
char c = s.charAt(0);
if (c != 's' && c != 'c' && c != 'r')
return false;
return s.startsWith("servlet:/") || s.startsWith("context:/") || s.startsWith("request:/");
}
private static String normalize(String s) {
s = URI.create(s).normalize().toString();
if (s.length() > 1 && s.charAt(s.length()-1) == '/')
s = s.substring(0, s.length()-1);
return s;
}
private static boolean hasDotSegments(String s) {
if (s == null)
return false;
for (int i = 0; i < s.length()-1; i++) {
char c = s.charAt(i);
if (i == 0 && c == '/')
return true;
if (c == '/' && s.charAt(i+1) == '.')
return true;
}
return false;
}
}