com.linecorp.armeria.common.Flags Maven / Gradle / Ivy
/*
* Copyright 2017 LINE Corporation
*
* LINE Corporation 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 com.linecorp.armeria.common;
import java.util.List;
import java.util.Optional;
import java.util.function.IntPredicate;
import java.util.function.LongPredicate;
import java.util.function.Predicate;
import javax.annotation.Nullable;
import javax.net.ssl.SSLEngine;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.github.benmanes.caffeine.cache.Cache;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.CaffeineSpec;
import com.google.common.base.Ascii;
import com.google.common.base.CharMatcher;
import com.google.common.base.Splitter;
import com.linecorp.armeria.client.ClientFactoryBuilder;
import com.linecorp.armeria.client.retry.Backoff;
import com.linecorp.armeria.client.retry.RetryingHttpClient;
import com.linecorp.armeria.client.retry.RetryingRpcClient;
import com.linecorp.armeria.common.util.Exceptions;
import com.linecorp.armeria.server.PathMappingContext;
import com.linecorp.armeria.server.ServiceConfig;
import io.netty.channel.epoll.Epoll;
import io.netty.handler.ssl.OpenSsl;
/**
* The system properties that affect Armeria's runtime behavior.
*/
public final class Flags {
private static final Logger logger = LoggerFactory.getLogger(Flags.class);
private static final Splitter CSV_SPLITTER = Splitter.on(',').trimResults().omitEmptyStrings();
private static final String PREFIX = "com.linecorp.armeria.";
private static final int NUM_CPU_CORES = Runtime.getRuntime().availableProcessors();
private static final boolean VERBOSE_EXCEPTIONS = getBoolean("verboseExceptions", false);
private static final boolean VERBOSE_RESPONSES = getBoolean("verboseResponses", false);
private static final boolean USE_EPOLL = getBoolean("useEpoll", Epoll.isAvailable(),
value -> Epoll.isAvailable() || !value);
private static final boolean USE_OPENSSL = getBoolean("useOpenSsl", OpenSsl.isAvailable(),
value -> OpenSsl.isAvailable() || !value);
private static final int DEFAULT_MAX_NUM_CONNECTIONS = Integer.MAX_VALUE;
private static final int MAX_NUM_CONNECTIONS =
getInt("maxNumConnections", DEFAULT_MAX_NUM_CONNECTIONS, value -> value > 0);
private static final int DEFAULT_NUM_COMMON_WORKERS = NUM_CPU_CORES * 2;
private static final int NUM_COMMON_WORKERS =
getInt("numCommonWorkers", DEFAULT_NUM_COMMON_WORKERS, value -> value > 0);
private static final int DEFAULT_NUM_COMMON_BLOCKING_TASK_THREADS = 200; // from Tomcat default maxThreads
private static final int NUM_COMMON_BLOCKING_TASK_THREADS =
getInt("numCommonBlockingTaskThreads",
DEFAULT_NUM_COMMON_BLOCKING_TASK_THREADS,
value -> value > 0);
private static final long DEFAULT_DEFAULT_MAX_REQUEST_LENGTH = 10 * 1024 * 1024; // 10 MiB
private static final long DEFAULT_MAX_REQUEST_LENGTH =
getLong("defaultMaxRequestLength",
DEFAULT_DEFAULT_MAX_REQUEST_LENGTH,
value -> value >= 0);
private static final long DEFAULT_DEFAULT_MAX_RESPONSE_LENGTH = 10 * 1024 * 1024; // 10 MiB
private static final long DEFAULT_MAX_RESPONSE_LENGTH =
getLong("defaultMaxResponseLength",
DEFAULT_DEFAULT_MAX_RESPONSE_LENGTH,
value -> value >= 0);
private static final long DEFAULT_DEFAULT_REQUEST_TIMEOUT_MILLIS = 10 * 1000; // 10 seconds
private static final long DEFAULT_REQUEST_TIMEOUT_MILLIS =
getLong("defaultRequestTimeoutMillis",
DEFAULT_DEFAULT_REQUEST_TIMEOUT_MILLIS,
value -> value >= 0);
// Use slightly greater value than the default request timeout so that clients have a higher chance of
// getting proper 503 Service Unavailable response when server-side timeout occurs.
private static final long DEFAULT_DEFAULT_RESPONSE_TIMEOUT_MILLIS = 15 * 1000; // 15 seconds
private static final long DEFAULT_RESPONSE_TIMEOUT_MILLIS =
getLong("defaultResponseTimeoutMillis",
DEFAULT_DEFAULT_RESPONSE_TIMEOUT_MILLIS,
value -> value >= 0);
private static final long DEFAULT_DEFAULT_CONNECT_TIMEOUT_MILLIS = 3200; // 3.2 seconds
private static final long DEFAULT_CONNECT_TIMEOUT_MILLIS =
getLong("defaultConnectTimeoutMillis",
DEFAULT_DEFAULT_CONNECT_TIMEOUT_MILLIS,
value -> value > 0);
// Use slightly greater value than the client-side default so that clients close the connection more often.
private static final long DEFAULT_DEFAULT_SERVER_IDLE_TIMEOUT_MILLIS = 15000; // 15 seconds
private static final long DEFAULT_SERVER_IDLE_TIMEOUT_MILLIS =
getLong("defaultServerIdleTimeoutMillis",
DEFAULT_DEFAULT_SERVER_IDLE_TIMEOUT_MILLIS,
value -> value >= 0);
private static final long DEFAULT_DEFAULT_CLIENT_IDLE_TIMEOUT_MILLIS = 10000; // 10 seconds
private static final long DEFAULT_CLIENT_IDLE_TIMEOUT_MILLIS =
getLong("defaultClientIdleTimeoutMillis",
DEFAULT_DEFAULT_CLIENT_IDLE_TIMEOUT_MILLIS,
value -> value >= 0);
private static final int DEFAULT_DEFAULT_MAX_HTTP1_INITIAL_LINE_LENGTH =
4096; // from Netty default maxHttp1InitialLineLength
private static final int DEFAULT_MAX_HTTP1_INITIAL_LINE_LENGTH =
getInt("defaultMaxHttp1InitialLineLength",
DEFAULT_DEFAULT_MAX_HTTP1_INITIAL_LINE_LENGTH,
value -> value >= 0);
private static final int DEFAULT_DEFAULT_MAX_HTTP1_HEADER_SIZE = 8192; // from Netty default maxHeaderSize
private static final int DEFAULT_MAX_HTTP1_HEADER_SIZE =
getInt("defaultMaxHttp1HeaderSize",
DEFAULT_DEFAULT_MAX_HTTP1_HEADER_SIZE,
value -> value >= 0);
private static final int DEFAULT_DEFAULT_MAX_HTTP1_CHUNK_SIZE = 8192; // from Netty default maxChunkSize
private static final int DEFAULT_MAX_HTTP1_CHUNK_SIZE =
getInt("defaultMaxHttp1ChunkSize",
DEFAULT_DEFAULT_MAX_HTTP1_CHUNK_SIZE,
value -> value >= 0);
private static final boolean DEFAULT_USE_HTTP2_PREFACE = getBoolean("defaultUseHttp2Preface", true);
private static final boolean DEFAULT_USE_HTTP1_PIPELINING = getBoolean("defaultUseHttp1Pipelining", false);
private static final String DEFAULT_DEFAULT_BACKOFF_SPEC =
"exponential=200:10000,jitter=0.2";
private static final String DEFAULT_BACKOFF_SPEC =
getNormalized("defaultBackoffSpec", DEFAULT_DEFAULT_BACKOFF_SPEC, value -> {
try {
Backoff.of(value);
return true;
} catch (Exception e) {
// Invalid backoff specification
return false;
}
});
private static final int DEFAULT_DEFAULT_MAX_TOTAL_ATTEMPTS = 10;
private static final int DEFAULT_MAX_TOTAL_ATTEMPTS =
getInt("defaultMaxTotalAttempts",
DEFAULT_DEFAULT_MAX_TOTAL_ATTEMPTS,
value -> value > 0);
private static final String DEFAULT_ROUTE_CACHE_SPEC = "maximumSize=4096";
private static final Optional ROUTE_CACHE_SPEC =
caffeineSpec("routeCache", DEFAULT_ROUTE_CACHE_SPEC);
private static final String DEFAULT_COMPOSITE_SERVICE_CACHE_SPEC = "maximumSize=256";
private static final Optional COMPOSITE_SERVICE_CACHE_SPEC =
caffeineSpec("compositeServiceCache", DEFAULT_COMPOSITE_SERVICE_CACHE_SPEC);
private static final String DEFAULT_PARSED_PATH_CACHE_SPEC = "maximumSize=4096";
private static final Optional PARSED_PATH_CACHE_SPEC =
caffeineSpec("parsedPathCache", DEFAULT_PARSED_PATH_CACHE_SPEC);
private static final String DEFAULT_HEADER_VALUE_CACHE_SPEC = "maximumSize=4096";
private static final Optional HEADER_VALUE_CACHE_SPEC =
caffeineSpec("headerValueCache", DEFAULT_HEADER_VALUE_CACHE_SPEC);
private static final String DEFAULT_CACHED_HEADERS =
":authority,:scheme,:method,accept-encoding,content-type";
private static final List CACHED_HEADERS =
CSV_SPLITTER.splitToList(getNormalized(
"cachedHeaders", DEFAULT_CACHED_HEADERS, CharMatcher.ascii()::matchesAllOf));
static {
if (!Epoll.isAvailable()) {
final Throwable cause = Exceptions.peel(Epoll.unavailabilityCause());
logger.info("/dev/epoll not available: {}", cause.toString());
} else if (USE_EPOLL) {
logger.info("Using /dev/epoll");
}
if (!OpenSsl.isAvailable()) {
final Throwable cause = Exceptions.peel(OpenSsl.unavailabilityCause());
logger.info("OpenSSL not available: {}", cause.toString());
} else if (USE_OPENSSL) {
logger.info("Using OpenSSL: {}, 0x{}",
OpenSsl.versionString(),
Long.toHexString(OpenSsl.version() & 0xFFFFFFFFL));
}
}
/**
* Returns whether the verbose exception mode is enabled. When enabled, the exceptions frequently thrown by
* Armeria will have full stack trace. When disabled, such exceptions will have empty stack trace to
* eliminate the cost of capturing the stack trace.
*
* This flag is disabled by default. Specify the {@code -Dcom.linecorp.armeria.verboseExceptions=true}
* JVM option to enable it.
*/
public static boolean verboseExceptions() {
return VERBOSE_EXCEPTIONS;
}
/**
* Returns whether the verbose response mode is enabled. When enabled, the server responses will contain
* the exception type and its full stack trace, which may be useful for debugging while potentially
* insecure. When disabled, the server responses will not expose such server-side details to the client.
*
*
This flag is disabled by default. Specify the {@code -Dcom.linecorp.armeria.verboseResponses=true}
* JVM option to enable it.
*/
public static boolean verboseResponses() {
return VERBOSE_RESPONSES;
}
/**
* Returns whether the JNI-based {@code /dev/epoll} socket I/O is enabled. When enabled on Linux, Armeria
* uses {@code /dev/epoll} directly for socket I/O. When disabled, {@code java.nio} socket API is used
* instead.
*
*
This flag is enabled by default for supported platforms. Specify the
* {@code -Dcom.linecorp.armeria.useEpoll=false} JVM option to disable it.
*/
public static boolean useEpoll() {
return USE_EPOLL;
}
/**
* Returns whether the JNI-based TLS support with OpenSSL is enabled. When enabled, Armeria uses OpenSSL
* for processing TLS connections. When disabled, the current JVM's default {@link SSLEngine} is used
* instead.
*
*
This flag is enabled by default for supported platforms. Specify the
* {@code -Dcom.linecorp.armeria.useOpenSsl=false} JVM option to disable it.
*/
public static boolean useOpenSsl() {
return USE_OPENSSL;
}
/**
* Returns the default server-side maximum number of connections.
*
*
The default value of this flag is {@value #DEFAULT_MAX_NUM_CONNECTIONS}. Specify the
* {@code -Dcom.linecorp.armeria.maxNumConnections=} JVM option to override
* the default value.
*/
public static int maxNumConnections() {
return MAX_NUM_CONNECTIONS;
}
/**
* Returns the default number of {@linkplain CommonPools#workerGroup() common worker group} threads.
* Note that this value has effect only if a user did not specify a worker group.
*
* The default value of this flag is {@code 2 * }. Specify the
* {@code -Dcom.linecorp.armeria.numCommonWorkers=} JVM option to override the default value.
*/
public static int numCommonWorkers() {
return NUM_COMMON_WORKERS;
}
/**
* Returns the default number of {@linkplain CommonPools#blockingTaskExecutor() blocking task executor}
* threads. Note that this value has effect only if a user did not specify a blocking task executor.
*
* The default value of this flag is {@value #DEFAULT_NUM_COMMON_BLOCKING_TASK_THREADS}. Specify the
* {@code -Dcom.linecorp.armeria.numCommonBlockingTaskThreads=} JVM option to override
* the default value.
*/
public static int numCommonBlockingTaskThreads() {
return NUM_COMMON_BLOCKING_TASK_THREADS;
}
/**
* Returns the default server-side maximum length of a request. Note that this value has effect
* only if a user did not specify it.
*
* The default value of this flag is {@value #DEFAULT_DEFAULT_MAX_REQUEST_LENGTH}. Specify the
* {@code -Dcom.linecorp.armeria.defaultMaxRequestLength=} to override the default value.
* {@code 0} disables the length limit.
*/
public static long defaultMaxRequestLength() {
return DEFAULT_MAX_REQUEST_LENGTH;
}
/**
* Returns the default client-side maximum length of a response. Note that this value has effect
* only if a user did not specify it.
*
* The default value of this flag is {@value #DEFAULT_DEFAULT_MAX_RESPONSE_LENGTH}. Specify the
* {@code -Dcom.linecorp.armeria.defaultMaxResponseLength=} to override the default value.
* {@code 0} disables the length limit.
*/
public static long defaultMaxResponseLength() {
return DEFAULT_MAX_RESPONSE_LENGTH;
}
/**
* Returns the default server-side timeout of a request in milliseconds. Note that this value has effect
* only if a user did not specify it.
*
* The default value of this flag is {@value #DEFAULT_DEFAULT_REQUEST_TIMEOUT_MILLIS}.
* Specify the {@code -Dcom.linecorp.armeria.defaultRequestTimeoutMillis=} to override
* the default value. {@code 0} disables the timeout.
*/
public static long defaultRequestTimeoutMillis() {
return DEFAULT_REQUEST_TIMEOUT_MILLIS;
}
/**
* Returns the default client-side timeout of a response in milliseconds. Note that this value has effect
* only if a user did not specify it.
*
* The default value of this flag is {@value #DEFAULT_DEFAULT_RESPONSE_TIMEOUT_MILLIS}.
* Specify the {@code -Dcom.linecorp.armeria.defaultResponseTimeoutMillis=} to override
* the default value. {@code 0} disables the timeout.
*/
public static long defaultResponseTimeoutMillis() {
return DEFAULT_RESPONSE_TIMEOUT_MILLIS;
}
/**
* Returns the default client-side timeout of a socket connection attempt in milliseconds.
* Note that this value has effect only if a user did not specify it.
*
* The default value of this flag is {@value #DEFAULT_DEFAULT_CONNECT_TIMEOUT_MILLIS}. Specify the
* {@code -Dcom.linecorp.armeria.defaultConnectTimeoutMillis=} JVM option to override
* the default value.
*/
public static long defaultConnectTimeoutMillis() {
return DEFAULT_CONNECT_TIMEOUT_MILLIS;
}
/**
* Returns the default server-side idle timeout of a connection for keep-alive in milliseconds.
* Note that this value has effect only if a user did not specify it.
*
* The default value of this flag is {@value #DEFAULT_DEFAULT_SERVER_IDLE_TIMEOUT_MILLIS}. Specify the
* {@code -Dcom.linecorp.armeria.defaultServerIdleTimeoutMillis=} JVM option to override
* the default value.
*/
public static long defaultServerIdleTimeoutMillis() {
return DEFAULT_SERVER_IDLE_TIMEOUT_MILLIS;
}
/**
* Returns the default client-side idle timeout of a connection for keep-alive in milliseconds.
* Note that this value has effect only if a user did not specify it.
*
* This default value of this flag is {@value #DEFAULT_DEFAULT_CLIENT_IDLE_TIMEOUT_MILLIS}. Specify the
* {@code -Dcom.linecorp.armeria.defaultClientIdleTimeoutMillis=} JVM option to override
* the default value.
*/
public static long defaultClientIdleTimeoutMillis() {
return DEFAULT_CLIENT_IDLE_TIMEOUT_MILLIS;
}
/**
* Returns the default maximum length of an HTTP/1 response initial line.
* Note that this value has effect only if a user did not specify it.
*
* This default value of this flag is {@value #DEFAULT_DEFAULT_MAX_HTTP1_INITIAL_LINE_LENGTH}.
* Specify the {@code -Dcom.linecorp.armeria.defaultMaxHttp1InitialLineLength=} JVM option
* to override the default value.
*/
public static int defaultMaxHttp1InitialLineLength() {
return DEFAULT_MAX_HTTP1_INITIAL_LINE_LENGTH;
}
/**
* Returns the default maximum length of all headers in an HTTP/1 response.
* Note that this value has effect only if a user did not specify it.
*
* This default value of this flag is {@value #DEFAULT_DEFAULT_MAX_HTTP1_HEADER_SIZE}.
* Specify the {@code -Dcom.linecorp.armeria.defaultMaxHttp1HeaderSize=} JVM option
* to override the default value.
*/
public static int defaultMaxHttp1HeaderSize() {
return DEFAULT_MAX_HTTP1_HEADER_SIZE;
}
/**
* Returns the default maximum length of each chunk in an HTTP/1 response content.
* The content or a chunk longer than this value will be split into smaller chunks
* so that their lengths never exceed it.
* Note that this value has effect only if a user did not specify it.
*
* This default value of this flag is {@value #DEFAULT_DEFAULT_MAX_HTTP1_CHUNK_SIZE}.
* Specify theb {@code -Dcom.linecorp.armeria.defaultMaxHttp1ChunkSize=} JVM option
* to override the default value.
*/
public static int defaultMaxHttp1ChunkSize() {
return DEFAULT_MAX_HTTP1_CHUNK_SIZE;
}
/**
* Returns the default value of the {@link ClientFactoryBuilder#useHttp2Preface(boolean)} option.
* Note that this value has effect only if a user did not specify it.
*
* This flag is enabled by default. Specify the
* {@code -Dcom.linecorp.armeria.defaultUseHttp2Preface=false} JVM option to disable it.
*/
public static boolean defaultUseHttp2Preface() {
return DEFAULT_USE_HTTP2_PREFACE;
}
/**
* Returns the default value of the {@link ClientFactoryBuilder#useHttp1Pipelining(boolean)} option.
* Note that this value has effect only if a user did not specify it.
*
*
This flag is disabled by default. Specify the
* {@code -Dcom.linecorp.armeria.defaultUseHttp1Pipelining=true} JVM option to enable it.
*/
public static boolean defaultUseHttp1Pipelining() {
return DEFAULT_USE_HTTP1_PIPELINING;
}
/**
* Returns the default value of the {@code backoffSpec} parameter when instantiating a {@link Backoff}
* using {@link Backoff#of(String)}. Note that this value has effect only if a user did not specify the
* {@code defaultBackoffSpec} in the constructor call.
*
*
The default value of this flag is {@value DEFAULT_DEFAULT_BACKOFF_SPEC}. Specify the
* {@code -Dcom.linecorp.armeria.defaultBackoffSpec=} JVM option to override the default value.
*/
public static String defaultBackoffSpec() {
return DEFAULT_BACKOFF_SPEC;
}
/**
* Returns the default maximum number of total attempts. Note that this value has effect only if a user
* did not specify it when creating a {@link RetryingHttpClient} or a {@link RetryingRpcClient}.
*
* The default value of this flag is {@value #DEFAULT_DEFAULT_MAX_TOTAL_ATTEMPTS}. Specify the
* {@code -Dcom.linecorp.armeria.defaultMaxTotalAttempts=} JVM option to
* override the default value.
*/
public static int defaultMaxTotalAttempts() {
return DEFAULT_MAX_TOTAL_ATTEMPTS;
}
/**
* Returns the value of the {@code routeCache} parameter. It would be used to create a Caffeine
* {@link Cache} instance using {@link Caffeine#from(String)} for routing a request. The {@link Cache}
* would hold the mappings of {@link PathMappingContext} and the designated {@link ServiceConfig}
* for a request to improve server performance.
*
* The default value of this flag is {@value DEFAULT_ROUTE_CACHE_SPEC}. Specify the
* {@code -Dcom.linecorp.armeria.routeCache=} JVM option to override the default value.
* Also, specify {@code -Dcom.linecorp.armeria.routeCache=off} JVM option to disable it.
*/
public static Optional routeCacheSpec() {
return ROUTE_CACHE_SPEC;
}
/**
* Returns the value of the {@code parsedPathCache} parameter. It would be used to create a Caffeine
* {@link Cache} instance using {@link Caffeine#from(String)} mapping raw HTTP paths to parsed pair of
* path and query, after validation.
*
* The default value of this flag is {@value DEFAULT_PARSED_PATH_CACHE_SPEC}. Specify the
* {@code -Dcom.linecorp.armeria.parsedPathCache=} JVM option to override the default value.
* Also, specify {@code -Dcom.linecorp.armeria.parsedPathCache=off} JVM option to disable it.
*/
public static Optional parsedPathCacheSpec() {
return PARSED_PATH_CACHE_SPEC;
}
/**
* Returns the value of the {@code headerValueCache} parameter. It would be used to create a Caffeine
* {@link Cache} instance using {@link Caffeine#from(String)} mapping raw HTTP ascii header values to
* {@link String}.
*
* The default value of this flag is {@value DEFAULT_HEADER_VALUE_CACHE_SPEC}. Specify the
* {@code -Dcom.linecorp.armeria.headerValueCache=} JVM option to override the default value.
* Also, specify {@code -Dcom.linecorp.armeria.headerValueCache=off} JVM option to disable it.
*/
public static Optional headerValueCacheSpec() {
return HEADER_VALUE_CACHE_SPEC;
}
/**
* Returns the value of the {@code cachedHeaders} parameter which contains a comma-separated list of
* headers whose values are cached using {@code headerValueCache}.
*
* The default value of this flag is {@value DEFAULT_CACHED_HEADERS}. Specify the
* {@code -Dcom.linecorp.armeria.cachedHeaders=} JVM option to override the default value.
*/
public static List cachedHeaders() {
return CACHED_HEADERS;
}
/**
* Returns the value of the {@code compositeServiceCache} parameter. It would be used to create a
* Caffeine {@link Cache} instance using {@link Caffeine#from(String)} for routing a request.
* The {@link Cache} would hold the mappings of {@link PathMappingContext} and the designated
* {@link ServiceConfig} for a request to improve server performance.
*
* The default value of this flag is {@value DEFAULT_COMPOSITE_SERVICE_CACHE_SPEC}. Specify the
* {@code -Dcom.linecorp.armeria.compositeServiceCache=} JVM option to override the default value.
* Also, specify {@code -Dcom.linecorp.armeria.compositeServiceCache=off} JVM option to disable it.
*/
public static Optional compositeServiceCacheSpec() {
return COMPOSITE_SERVICE_CACHE_SPEC;
}
private static Optional caffeineSpec(String name, String defaultValue) {
final String spec = get(name, defaultValue, value -> {
try {
if (!"off".equals(value)) {
CaffeineSpec.parse(value);
}
return true;
} catch (Exception e) {
return false;
}
});
return "off".equals(spec) ? Optional.empty()
: Optional.of(spec);
}
private static boolean getBoolean(String name, boolean defaultValue) {
return getBoolean(name, defaultValue, value -> true);
}
private static boolean getBoolean(String name, boolean defaultValue, Predicate validator) {
return "true".equals(getNormalized(name, String.valueOf(defaultValue), value -> {
if ("true".equals(value)) {
return validator.test(true);
}
if ("false".equals(value)) {
return validator.test(false);
}
return false;
}));
}
private static int getInt(String name, int defaultValue, IntPredicate validator) {
return Integer.parseInt(getNormalized(name, String.valueOf(defaultValue), value -> {
try {
return validator.test(Integer.parseInt(value));
} catch (Exception e) {
// null or non-integer
return false;
}
}));
}
private static long getLong(String name, long defaultValue, LongPredicate validator) {
return Long.parseLong(getNormalized(name, String.valueOf(defaultValue), value -> {
try {
return validator.test(Long.parseLong(value));
} catch (Exception e) {
// null or non-integer
return false;
}
}));
}
private static String get(String name, String defaultValue, Predicate validator) {
final String fullName = PREFIX + name;
final String value = System.getProperty(fullName);
if (value == null) {
logger.info("{}: {} (default)", fullName, defaultValue);
return defaultValue;
}
if (validator.test(value)) {
logger.info("{}: {}", fullName, value);
return value;
}
logger.info("{}: {} (default instead of: {})", fullName, defaultValue, value);
return defaultValue;
}
private static String getNormalized(String name, String defaultValue, Predicate validator) {
final String fullName = PREFIX + name;
final String value = getLowerCased(fullName);
if (value == null) {
logger.info("{}: {} (default)", fullName, defaultValue);
return defaultValue;
}
if (validator.test(value)) {
logger.info("{}: {}", fullName, value);
return value;
}
logger.info("{}: {} (default instead of: {})", fullName, defaultValue, value);
return defaultValue;
}
@Nullable
private static String getLowerCased(String fullName) {
String value = System.getProperty(fullName);
if (value != null) {
value = Ascii.toLowerCase(value);
}
return value;
}
private Flags() {}
}