Refactoring AnsiConsoleSupport (#266)

src/main/java/org/fusesource/jansi/AnsiConsole.java

@@ -31,6 +31,9 @@
 import org.fusesource.jansi.io.AnsiProcessor;
 import org.fusesource.jansi.io.FastBufferedOutputStream;
 
+import static org.fusesource.jansi.internal.AnsiConsoleSupportHolder.getCLibrary;
+import static org.fusesource.jansi.internal.AnsiConsoleSupportHolder.getKernel32;
+
 /**
  * Provides consistent access to an ANSI aware console PrintStream or an ANSI codes stripping PrintStream
  * if not on a terminal (see
@@ -155,10 +158,21 @@ public class AnsiConsole {
  */
  public static final String JANSI_GRACEFUL = "jansi.graceful";
 
+ /**
+ * The {@code jansi.providers} system property can be set to control which internal provider
+ * will be used. If this property is not set, the {@code ffm} provider will be used if available,
+ * else the {@code jni} one will be used. If set, this property is interpreted as a comma
+ * separated list of provider names to try in order.
+ */
  public static final String JANSI_PROVIDERS = "jansi.providers";
+ /**
+ * The name of the {@code jni} provider.
+ */
  public static final String JANSI_PROVIDER_JNI = "jni";
+ /**
+ * The name of the {@code ffm} provider.
+ */
  public static final String JANSI_PROVIDER_FFM = "ffm";
- public static final String JANSI_PROVIDERS_DEFAULT = JANSI_PROVIDER_FFM + "," + JANSI_PROVIDER_JNI;
 
  /**
  * @deprecated this field will be made private in a future release, use {@link #sysOut()} instead
@@ -536,12 +550,4 @@ static synchronized void initStreams() {
  initialized = true;
  }
  }
-
- private static AnsiConsoleSupport.Kernel32 getKernel32() {
- return AnsiConsoleSupport.getInstance().getKernel32();
- }
-
- private static AnsiConsoleSupport.CLibrary getCLibrary() {
- return AnsiConsoleSupport.getInstance().getCLibrary();
- }
 }

src/main/java/org/fusesource/jansi/AnsiMain.java

@@ -23,10 +23,11 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.PrintStream;
-import java.nio.charset.StandardCharsets;
 import java.util.Properties;
 
 import org.fusesource.jansi.Ansi.Attribute;
+import org.fusesource.jansi.internal.AnsiConsoleSupport;
+import org.fusesource.jansi.internal.AnsiConsoleSupportHolder;
 import org.fusesource.jansi.internal.JansiLoader;
 import org.fusesource.jansi.internal.MingwSupport;
 
@@ -56,9 +57,8 @@ public static void main(String... args) throws IOException {
 
  System.out.println();
 
- System.out.println("jansi.providers= "
- + System.getProperty(AnsiConsole.JANSI_PROVIDERS, AnsiConsole.JANSI_PROVIDERS_DEFAULT));
- String provider = AnsiConsoleSupport.getInstance().getProviderName();
+ System.out.println("jansi.providers= " + System.getProperty(AnsiConsole.JANSI_PROVIDERS, ""));
+ String provider = AnsiConsoleSupportHolder.getProviderName();
  System.out.println("Selected provider: " + provider);
 
  if (AnsiConsole.JANSI_PROVIDER_JNI.equals(provider)) {
@@ -204,8 +204,8 @@ private static void diagnoseTty(boolean stderr) {
  int isatty;
  int width;
  if (AnsiConsole.IS_WINDOWS) {
- long console = AnsiConsoleSupport.getInstance().getKernel32().getStdHandle(!stderr);
- isatty = AnsiConsoleSupport.getInstance().getKernel32().isTty(console);
+ long console = AnsiConsoleSupportHolder.getKernel32().getStdHandle(!stderr);
+ isatty = AnsiConsoleSupportHolder.getKernel32().isTty(console);
  if ((AnsiConsole.IS_CONEMU || AnsiConsole.IS_CYGWIN || AnsiConsole.IS_MSYSTEM) && isatty == 0) {
  MingwSupport mingw = new MingwSupport();
  String name = mingw.getConsoleName(!stderr);
@@ -217,12 +217,12 @@ private static void diagnoseTty(boolean stderr) {
  width = 0;
  }
  } else {
- width = AnsiConsoleSupport.getInstance().getKernel32().getTerminalWidth(console);
+ width = AnsiConsoleSupportHolder.getKernel32().getTerminalWidth(console);
  }
  } else {
  int fd = stderr ? AnsiConsoleSupport.CLibrary.STDERR_FILENO : AnsiConsoleSupport.CLibrary.STDOUT_FILENO;
- isatty = AnsiConsoleSupport.getInstance().getCLibrary().isTty(fd);
- width = AnsiConsoleSupport.getInstance().getCLibrary().getTerminalWidth(fd);
+ isatty = AnsiConsoleSupportHolder.getCLibrary().isTty(fd);
+ width = AnsiConsoleSupportHolder.getCLibrary().getTerminalWidth(fd);
  }
 
  System.out.println("isatty(STD" + (stderr ? "ERR" : "OUT") + "_FILENO): " + isatty + ", System."

src/main/java/org/fusesource/jansi/WindowsSupport.java

@@ -15,18 +15,16 @@
  */
 package org.fusesource.jansi;
 
+import org.fusesource.jansi.internal.AnsiConsoleSupportHolder;
+
 public class WindowsSupport {
 
  public static String getLastErrorMessage() {
- int errorCode = getKernel32().getLastError();
+ int errorCode = AnsiConsoleSupportHolder.getKernel32().getLastError();
  return getErrorMessage(errorCode);
  }
 
  public static String getErrorMessage(int errorCode) {
- return getKernel32().getErrorMessage(errorCode);
- }
-
- private static AnsiConsoleSupport.Kernel32 getKernel32() {
- return AnsiConsoleSupport.getInstance().getKernel32();
+ return AnsiConsoleSupportHolder.getKernel32().getErrorMessage(errorCode);
  }
 }

src/main/java/org/fusesource/jansi/AnsiConsoleSupport.java → src/main/java/org/fusesource/jansi/internal/AnsiConsoleSupport.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.fusesource.jansi;
+package org.fusesource.jansi.internal;
 
 import java.io.IOException;
 import java.io.OutputStream;
@@ -56,8 +56,4 @@ interface Kernel32 {
  CLibrary getCLibrary();
 
  Kernel32 getKernel32();
-
- static AnsiConsoleSupport getInstance() {
- return AnsiConsoleSupportHolder.get();
- }
 }

src/main/java/org/fusesource/jansi/internal/AnsiConsoleSupportHolder.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2009-2023 the original author(s).
+ *
+ * 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 org.fusesource.jansi.internal;
+
+import static org.fusesource.jansi.AnsiConsole.JANSI_PROVIDERS;
+
+public final class AnsiConsoleSupportHolder {
+
+ private static final String PROVIDER_NAME;
+ private static final AnsiConsoleSupport.CLibrary CLIBRARY;
+ private static final AnsiConsoleSupport.Kernel32 KERNEL32;
+ private static final Throwable ERR;
+
+ private static AnsiConsoleSupport getDefaultProvider() {
+ try {
+ // Call the specialized constructor to check whether the module has native access enabled
+ // If not, fallback to JNI to avoid the JDK printing warnings in stderr
+ return (AnsiConsoleSupport) Class.forName("org.fusesource.jansi.internal.ffm.AnsiConsoleSupportImpl")
+ .getConstructor(boolean.class)
+ .newInstance(true);
+ } catch (Throwable ignored) {
+ }
+
+ return new org.fusesource.jansi.internal.jni.AnsiConsoleSupportImpl();
+ }
+
+ private static AnsiConsoleSupport findProvider(String providerList) {
+ String[] providers = providerList.split(",");
+
+ RuntimeException error = null;
+
+ for (String provider : providers) {
+ try {
+ return (AnsiConsoleSupport)
+ Class.forName("org.fusesource.jansi.internal." + provider + ".AnsiConsoleSupportImpl")
+ .getConstructor()
+ .newInstance();
+ } catch (Throwable t) {
+ if (error == null) {
+ error = new RuntimeException("Unable to create AnsiConsoleSupport provider");
+ }
+
+ error.addSuppressed(t);
+ }
+ }
+
+ // User does not specify any provider, falling back to the default
+ if (error == null) {
+ return getDefaultProvider();
+ }
+
+ throw error;
+ }
+
+ static {
+ String providerList = System.getProperty(JANSI_PROVIDERS);
+
+ AnsiConsoleSupport ansiConsoleSupport = null;
+ Throwable err = null;
+
+ try {
+ if (providerList == null) {
+ ansiConsoleSupport = getDefaultProvider();
+ } else {
+ ansiConsoleSupport = findProvider(providerList);
+ }
+ } catch (Throwable e) {
+ err = e;
+ }
+
+ String providerName = null;
+ AnsiConsoleSupport.CLibrary clib = null;
+ AnsiConsoleSupport.Kernel32 kernel32 = null;
+
+ if (ansiConsoleSupport != null) {
+ try {
+ providerName = ansiConsoleSupport.getProviderName();
+ clib = ansiConsoleSupport.getCLibrary();
+ kernel32 = OSInfo.isWindows() ? ansiConsoleSupport.getKernel32() : null;
+ } catch (Throwable e) {
+ err = e;
+ }
+ }
+
+ PROVIDER_NAME = providerName;
+ CLIBRARY = clib;
+ KERNEL32 = kernel32;
+ ERR = err;
+ }
+
+ public static String getProviderName() {
+ return PROVIDER_NAME;
+ }
+
+ public static AnsiConsoleSupport.CLibrary getCLibrary() {
+ if (CLIBRARY == null) {
+ throw new RuntimeException("Unable to get the instance of CLibrary", ERR);
+ }
+
+ return CLIBRARY;
+ }
+
+ public static AnsiConsoleSupport.Kernel32 getKernel32() {
+ if (KERNEL32 == null) {
+ if (OSInfo.isWindows()) {
+ throw new RuntimeException("Unable to get the instance of Kernel32", ERR);
+ } else {
+ throw new UnsupportedOperationException("Not Windows");
+ }
+ }
+
+ return KERNEL32;
+ }
+}

src/main/java/org/fusesource/jansi/ffm/AnsiConsoleSupportFfm.java → src/main/java/org/fusesource/jansi/internal/ffm/AnsiConsoleSupportImpl.java

@@ -13,21 +13,30 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.fusesource.jansi.ffm;
+package org.fusesource.jansi.internal.ffm;
 
 import java.io.IOException;
 import java.io.OutputStream;
 import java.lang.foreign.Arena;
 import java.lang.foreign.MemorySegment;
 import java.lang.foreign.ValueLayout;
 
-import org.fusesource.jansi.AnsiConsoleSupport;
+import org.fusesource.jansi.internal.AnsiConsoleSupport;
 import org.fusesource.jansi.internal.OSInfo;
 import org.fusesource.jansi.io.AnsiProcessor;
 
-import static org.fusesource.jansi.ffm.Kernel32.*;
+import static org.fusesource.jansi.internal.ffm.Kernel32.*;
+
+public final class AnsiConsoleSupportImpl implements AnsiConsoleSupport {
+
+ public AnsiConsoleSupportImpl() {}
+
+ public AnsiConsoleSupportImpl(boolean checkNativeAccess) {
+ if (checkNativeAccess && !AnsiConsoleSupportImpl.class.getModule().isNativeAccessEnabled()) {
+ throw new UnsupportedOperationException("Native access is not enabled for the current module");
+ }
+ }
 
-public class AnsiConsoleSupportFfm implements AnsiConsoleSupport {
  @Override
  public String getProviderName() {
  return "ffm";
@@ -88,7 +97,7 @@ public int getLastError() {
 
  @Override
  public String getErrorMessage(int errorCode) {
- return org.fusesource.jansi.ffm.Kernel32.getErrorMessage(errorCode);
+ return org.fusesource.jansi.internal.ffm.Kernel32.getErrorMessage(errorCode);
  }
 
  @Override

src/main/java/org/fusesource/jansi/ffm/Kernel32.java → src/main/java/org/fusesource/jansi/internal/ffm/Kernel32.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.fusesource.jansi.ffm;
+package org.fusesource.jansi.internal.ffm;
 
 import java.io.IOException;
 import java.lang.foreign.AddressLayout;
@@ -309,7 +309,8 @@ public static String getErrorMessage(int errorCode) {
  int bufferSize = 160;
  try (Arena arena = Arena.ofConfined()) {
  MemorySegment data = arena.allocate(bufferSize);
- FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM, null, errorCode, 0, data, bufferSize, null);
+ FormatMessageW(
+ FORMAT_MESSAGE_FROM_SYSTEM, MemorySegment.NULL, errorCode, 0, data, bufferSize, MemorySegment.NULL);
  return new String(data.toArray(JAVA_BYTE), StandardCharsets.UTF_16LE).trim();
  }
  }