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/*
* Copyright 2005 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.opensymphony.xwork2.util.location;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Serializable;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
/**
* A simple immutable and serializable implementation of {@link Location}.
*/
public class LocationImpl implements Location, Serializable {
private final String uri;
private final int line;
private final int column;
private final String description;
// Package private: outside this package, use Location.UNKNOWN.
static final LocationImpl UNKNOWN = new LocationImpl(null, null, -1, -1);
/**
* Build a location for a given URI, with unknown line and column numbers.
*
* @param uri the resource URI
*/
public LocationImpl(String description, String uri) {
this(description, uri, -1, -1);
}
/**
* Build a location for a given URI and line and column numbers.
*
* @param uri the resource URI
* @param line the line number (starts at 1)
* @param column the column number (starts at 1)
*/
public LocationImpl(String description, String uri, int line, int column) {
if (uri == null || uri.length() == 0) {
this.uri = null;
this.line = -1;
this.column = -1;
} else {
this.uri = uri;
this.line = line;
this.column = column;
}
if (description != null && description.length() == 0) {
description = null;
}
this.description = description;
}
/**
* Copy constructor.
*
* @param location the location to be copied
*/
public LocationImpl(Location location) {
this(location.getDescription(), location.getURI(), location.getLineNumber(), location.getColumnNumber());
}
/**
* Create a location from an existing one, but with a different description
*/
public LocationImpl(String description, Location location) {
this(description, location.getURI(), location.getLineNumber(), location.getColumnNumber());
}
/**
* Obtain a LocationImpl from a {@link Location}. If location is
* already a LocationImpl, it is returned, otherwise it is copied.
*
* This method is useful when an immutable and serializable location is needed, such as in locatable
* exceptions.
*
* @param location the location
* @return an immutable and serializable version of location
*/
public static LocationImpl get(Location location) {
if (location instanceof LocationImpl) {
return (LocationImpl)location;
} else if (location == null) {
return UNKNOWN;
} else {
return new LocationImpl(location);
}
}
/**
* Get the description of this location
*
* @return the description (can be null)
*/
public String getDescription() {
return this.description;
}
/**
* Get the URI of this location
*
* @return the URI (null if unknown).
*/
public String getURI() {
return this.uri;
}
/**
* Get the line number of this location
*
* @return the line number (-1 if unknown)
*/
public int getLineNumber() {
return this.line;
}
/**
* Get the column number of this location
*
* @return the column number (-1 if unknown)
*/
public int getColumnNumber() {
return this.column;
}
/**
* Gets a source code snippet with the default padding
*
* @param padding The amount of lines before and after the error to include
*/
public List getSnippet(int padding) {
List snippet = new ArrayList();
if (getLineNumber() > 0) {
try {
InputStream in = new URL(getURI()).openStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
int lineno = 0;
int errno = getLineNumber();
String line;
while ((line = reader.readLine()) != null) {
lineno++;
if (lineno >= errno - padding && lineno <= errno + padding) {
snippet.add(line);
}
}
} catch (Exception ex) {
// ignoring as snippet not available isn't a big deal
}
}
return snippet;
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof Location) {
Location other = (Location)obj;
return this.line == other.getLineNumber() && this.column == other.getColumnNumber()
&& testEquals(this.uri, other.getURI())
&& testEquals(this.description, other.getDescription());
}
return false;
}
@Override
public int hashCode() {
int hash = line ^ column;
if (uri != null) hash ^= uri.hashCode();
if (description != null) hash ^= description.hashCode();
return hash;
}
@Override
public String toString() {
return LocationUtils.toString(this);
}
/**
* Ensure serialized unknown location resolve to {@link Location#UNKNOWN}.
*/
private Object readResolve() {
return this.equals(Location.UNKNOWN) ? Location.UNKNOWN : this;
}
private boolean testEquals(Object object1, Object object2) {
if (object1 == object2) {
return true;
}
if ((object1 == null) || (object2 == null)) {
return false;
}
return object1.equals(object2);
}
}