org.apache.tools.ant.filters.ReplaceTokens Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
*
* https://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 org.apache.tools.ant.filters;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.Hashtable;
import java.util.Map;
import java.util.Properties;
import java.util.SortedMap;
import java.util.TreeMap;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.types.Parameter;
import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.types.resources.FileResource;
import org.apache.tools.ant.util.FileUtils;
/**
* Replaces tokens in the original input with user-supplied values.
*
* Example:
*
* <replacetokens begintoken="#" endtoken="#">
* <token key="DATE" value="${TODAY}"/>
* </replacetokens>
*
* Or:
*
* <filterreader classname="org.apache.tools.ant.filters.ReplaceTokens">
* <param type="tokenchar" name="begintoken" value="#"/>
* <param type="tokenchar" name="endtoken" value="#"/>
* <param type="token" name="DATE" value="${TODAY}"/>
* </filterreader>
*
*/
public final class ReplaceTokens
extends BaseParamFilterReader
implements ChainableReader {
/** Default "begin token" character. */
private static final String DEFAULT_BEGIN_TOKEN = "@";
/** Default "end token" character. */
private static final String DEFAULT_END_TOKEN = "@";
/** Hashtable to holds the original replacee-replacer pairs (String to String). */
private Hashtable hash = new Hashtable<>();
/** This map holds the "resolved" tokens (begin- and end-tokens are added to make searching simpler) */
private final TreeMap resolvedTokens = new TreeMap<>();
private boolean resolvedTokensBuilt = false;
/** Used for comparisons and lookup into the resolvedTokens map. */
private String readBuffer = "";
/** replacement test from a token */
private String replaceData = null;
/** Index into replacement data */
private int replaceIndex = -1;
/** Character marking the beginning of a token. */
private String beginToken = DEFAULT_BEGIN_TOKEN;
/** Character marking the end of a token. */
private String endToken = DEFAULT_END_TOKEN;
/**
* Constructor for "dummy" instances.
*
* @see BaseFilterReader#BaseFilterReader()
*/
public ReplaceTokens() {
}
/**
* Creates a new filtered reader.
*
* @param in A Reader object providing the underlying stream.
* Must not be null.
*/
public ReplaceTokens(final Reader in) {
super(in);
}
/**
* Returns the next character in the filtered stream, replacing tokens
* from the original stream.
*
* @return the next character in the resulting stream, or -1
* if the end of the resulting stream has been reached
*
* @exception IOException if the underlying stream throws an IOException
* during reading
*/
public int read() throws IOException {
if (!getInitialized()) {
initialize();
setInitialized(true);
}
if (!resolvedTokensBuilt) {
// build the resolved tokens tree map.
for (Map.Entry entry : hash.entrySet()) {
resolvedTokens.put(beginToken + entry.getKey() + endToken, entry.getValue());
}
resolvedTokensBuilt = true;
}
// are we currently serving replace data?
if (replaceData != null) {
if (replaceIndex < replaceData.length()) {
return replaceData.charAt(replaceIndex++);
} else {
replaceData = null;
}
}
// is the read buffer empty?
if (readBuffer.isEmpty()) {
int next = in.read();
if (next == -1) {
return next; // end of stream. all buffers empty.
}
readBuffer += (char) next;
}
for (;;) {
// get the closest tokens
SortedMap possibleTokens = resolvedTokens.tailMap(readBuffer);
if (possibleTokens.isEmpty() || !possibleTokens.firstKey().startsWith(readBuffer)) { // if there is none, then deliver the first char from the buffer.
return getFirstCharacterFromReadBuffer();
} else if (readBuffer.equals(possibleTokens.firstKey())) { // there exists a nearest token - is it an exact match?
// we have found a token. prepare the replaceData buffer.
replaceData = resolvedTokens.get(readBuffer);
replaceIndex = 0;
readBuffer = ""; // destroy the readBuffer - it's contents are being replaced entirely.
// get the first character via recursive call.
return read();
} else { // nearest token is not matching exactly - read one character more.
int next = in.read();
if (next != -1) {
readBuffer += (char) next;
} else {
return getFirstCharacterFromReadBuffer(); // end of stream. deliver remaining characters from buffer.
}
}
}
}
/**
* @return the first character from the read buffer or -1 if read buffer is empty.
*/
private int getFirstCharacterFromReadBuffer() {
if (readBuffer.isEmpty()) {
return -1;
}
int chr = readBuffer.charAt(0);
readBuffer = readBuffer.substring(1);
return chr;
}
/**
* Sets the "begin token" character.
*
* @param beginToken the character used to denote the beginning of a token
*/
public void setBeginToken(final String beginToken) {
this.beginToken = beginToken;
}
/**
* Returns the "begin token" character.
*
* @return the character used to denote the beginning of a token
*/
private String getBeginToken() {
return beginToken;
}
/**
* Sets the "end token" character.
*
* @param endToken the character used to denote the end of a token
*/
public void setEndToken(final String endToken) {
this.endToken = endToken;
}
/**
* Returns the "end token" character.
*
* @return the character used to denote the end of a token
*/
private String getEndToken() {
return endToken;
}
/**
* A resource containing properties, each of which is interpreted
* as a token/value pair.
*
* @param r Resource
* @since Ant 1.8.0
*/
public void setPropertiesResource(Resource r) {
makeTokensFromProperties(r);
}
/**
* Adds a token element to the map of tokens to replace.
*
* @param token The token to add to the map of replacements.
* Must not be null.
*/
public void addConfiguredToken(final Token token) {
hash.put(token.getKey(), token.getValue());
resolvedTokensBuilt = false; // invalidate to build them again if they have been built already.
}
/**
* Returns properties from a specified properties file.
*
* @param resource The resource to load properties from.
*/
private Properties getProperties(Resource resource) {
InputStream in = null;
Properties props = new Properties();
try {
in = resource.getInputStream();
props.load(in);
} catch (IOException ioe) {
if (getProject() != null) {
getProject().log("getProperties failed, " + ioe.getMessage(), Project.MSG_ERR);
} else {
ioe.printStackTrace(); //NOSONAR
}
} finally {
FileUtils.close(in);
}
return props;
}
/**
* Sets the map of tokens to replace.
*
* @param hash A map (String->String) of token keys to replacement
* values. Must not be null.
*/
private void setTokens(final Hashtable hash) {
this.hash = hash;
}
/**
* Returns the map of tokens which will be replaced.
*
* @return a map (String->String) of token keys to replacement
* values
*/
private Hashtable getTokens() {
return hash;
}
/**
* Creates a new ReplaceTokens using the passed in
* Reader for instantiation.
*
* @param rdr A Reader object providing the underlying stream.
* Must not be null.
*
* @return a new filter based on this configuration, but filtering
* the specified reader
*/
public Reader chain(final Reader rdr) {
ReplaceTokens newFilter = new ReplaceTokens(rdr);
newFilter.setBeginToken(getBeginToken());
newFilter.setEndToken(getEndToken());
newFilter.setTokens(getTokens());
newFilter.setInitialized(true);
return newFilter;
}
/**
* Initializes tokens and loads the replacee-replacer hashtable.
*/
private void initialize() {
Parameter[] params = getParameters();
if (params != null) {
for (Parameter param : params) {
if (param != null) {
final String type = param.getType();
if ("tokenchar".equals(type)) {
final String name = param.getName();
if ("begintoken".equals(name)) {
beginToken = param.getValue();
} else if ("endtoken".equals(name)) {
endToken = param.getValue();
}
} else if ("token".equals(type)) {
final String name = param.getName();
final String value = param.getValue();
hash.put(name, value);
} else if ("propertiesfile".equals(type)) {
makeTokensFromProperties(
new FileResource(new File(param.getValue())));
}
}
}
}
}
private void makeTokensFromProperties(Resource r) {
Properties props = getProperties(r);
props.stringPropertyNames().forEach(key -> hash.put(key, props.getProperty(key)));
}
/**
* Holds a token
*/
public static class Token {
/** Token key */
private String key;
/** Token value */
private String value;
/**
* Sets the token key
*
* @param key The key for this token. Must not be null.
*/
public final void setKey(String key) {
this.key = key;
}
/**
* Sets the token value
*
* @param value The value for this token. Must not be null.
*/
public final void setValue(String value) {
this.value = value;
}
/**
* Returns the key for this token.
*
* @return the key for this token
*/
public final String getKey() {
return key;
}
/**
* Returns the value for this token.
*
* @return the value for this token
*/
public final String getValue() {
return value;
}
}
}