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Troxy is a proxy intended for simulating a remote service without actually
connecting to the server. Incoming requests are matched using regular
expressions and responses are created from a recorded response from the remote
service and optionally modified by inserting values caught from the regular
expression used to match the request.
package no.sb1.troxy.common;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A wrapper class handling configuration parameters.
*/
public final class Config {
/**
* Logger for this class.
*/
private static final Logger log = LoggerFactory.getLogger(Config.class);
/**
* Properties object storing the actual configuration.
*/
private final Map SETTINGS = new HashMap<>();
/**
* Pattern for file inclusion.
*/
private static final Pattern INCLUDE_PATTERN = Pattern.compile("^\\s*@include\\s*([^\n]+)\\s*$");
private final Path path;
/**
* Private constructor to prevent instantiation.
*/
private Config(final Path path) {
this.path = path;
reload();
}
public String getConfigFile() {
return path.toAbsolutePath().toString();
}
/**
* Fetch all key/value pairs in the configuration.
* @return All key/value pairs in the configuration.
*/
public Map getKeysAndValues() {
return getKeysAndValues("");
}
/**
* Fetch all key/value pairs in the configuration where key begins with the given prefix.
* @param prefix Prefix for keys in configuration.
* @return All key/value pairs in the configuration where key begins with the given prefix.
*/
public Map getKeysAndValues(String prefix) {
log.debug("Requesting all keys & values for key names starting with \"{}\"", prefix);
Map entries = new HashMap<>();
for (Map.Entry entry : SETTINGS.entrySet()) {
String key = entry.getKey();
if (key.startsWith(prefix))
entries.put(key, entry.getValue());
}
return entries;
}
/**
* Get the value for the given key, setting it to null if key is not found.
* @param key The key for the value.
* @return The value for the key, null if key was not found.
*/
public String getValue(String key) {
if (!SETTINGS.containsKey(key)) {
log.info("Requested key \"{}\" not found in configuration, returning null", key);
return null;
}
return SETTINGS.get(key);
}
/**
* Get the value for the given key, setting it to defaultValue if key is not found.
* @param key The key for the value.
* @param defaultValue The value to set if key is not found.
* @return The value for the key, defaultValue if key was not found.
*/
public String getValue(String key, String defaultValue) {
if (!SETTINGS.containsKey(key)) {
log.debug("Requested key \"{}\" not found in configuration, adding it with value \"{}\"", key, defaultValue);
SETTINGS.put(key, defaultValue);
return defaultValue;
}
return SETTINGS.get(key);
}
/**
* Load the properties from the configuration file.
*/
public void reload() {
log.debug("Reading configuration");
Properties newSettings = new Properties();
try {
newSettings.load(readPropertiesFile(path, new HashSet<>()));
} catch (IOException e) {
log.warn("Unable to load properties from file {}", path, e);
return;
}
/* mark existing configuration values and forget them if they're not set in new configuration */
Set oldKeys = new HashSet<>(SETTINGS.keySet());
for (String key : newSettings.stringPropertyNames()) {
/* update properties */
String value = newSettings.getProperty(key) == null ? "" : newSettings.getProperty(key).trim();
if (SETTINGS.containsKey(key)) {
String oldValue = SETTINGS.get(key);
/* key already exist, but has the value changed? */
if (!value.equals(oldValue))
log.info("Key \"{}\" with value \"{}\" was updated to new value \"{}\"", key, oldValue, value);
} else {
/* new key/value pair */
log.info("Key \"{}\" with value \"{}\" was added", key, value);
}
SETTINGS.put(key, value);
/* remove key from oldKeys */
oldKeys.remove(key);
}
for (String key : oldKeys) {
log.info("Key \"{}\" with value \"{}\" was removed", key, SETTINGS.get(key));
SETTINGS.remove(key);
}
}
private static InputStream readPropertiesFile(Path path, Set alreadyIncluded) throws IOException {
alreadyIncluded.add(path);
try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
Files.lines(path).forEachOrdered(line -> {
try {
Matcher matcher = INCLUDE_PATTERN.matcher(line);
if (matcher.matches()) {
Path includePath = path.getParent();
String includeFile = matcher.group(1);
includePath = includePath == null ? Paths.get(includeFile) : includePath.resolve(includeFile);
if (!alreadyIncluded.contains(includePath)) {
log.info("Including properties file {}", includePath);
InputStream is = readPropertiesFile(includePath, alreadyIncluded);
int read;
byte[] data = new byte[4096];
while ((read = is.read(data)) >= 0)
baos.write(data, 0, read);
}
} else {
baos.write((line + "\n").getBytes());
}
} catch (IOException e) {
log.warn("Unable to read properties file {}", path, e);
}
});
return new ByteArrayInputStream(baos.toByteArray());
}
}
public static Config load(final Path path) {
return new Config(path);
}
}