Change the behavior to fail gracefuly in case the system is not suppo…

…rted, fixes #204
fusesource · Oct 11, 2021 · 98c430a · 98c430a
1 parent cb843bf
commit 98c430a
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Showing 5 changed files with 61 additions and 21 deletions.
diff --git a/src/main/java/org/fusesource/jansi/AnsiConsole.java b/src/main/java/org/fusesource/jansi/AnsiConsole.java
@@ -161,6 +161,12 @@ public class AnsiConsole {
      * reset when the streams are uninstalled.
      */
     public static final String JANSI_NORESET = "jansi.noreset";
+    /**
+     * If the <code>jansi.graceful</code> system property is set to false, any exception that occurs
+     * during the initialization will cause the library to report this exception and fail. The default
+     * behavior is to behave gracefully and fall back to pure emulation on posix systems.
+     */
+    public static final String JANSI_GRACEFUL = "jansi.graceful";
 
     /**
      * @deprecated this field will be made private in a future release, use {@link #sysOut()} instead

diff --git a/src/main/java/org/fusesource/jansi/AnsiMain.java b/src/main/java/org/fusesource/jansi/AnsiMain.java
@@ -57,10 +57,26 @@ public static void main(String... args) throws IOException {
         // info on native library
         System.out.println("library.jansi.path= " + System.getProperty("library.jansi.path", ""));
         System.out.println("library.jansi.version= " + System.getProperty("library.jansi.version", ""));
-        JansiLoader.initialize();
-        System.out.println("Jansi native library loaded from " + JansiLoader.getNativeLibraryPath());
-        if (JansiLoader.getNativeLibrarySourceUrl() != null) {
-            System.out.println("   which was auto-extracted from " + JansiLoader.getNativeLibrarySourceUrl());
+        boolean loaded = JansiLoader.initialize();
+        if (loaded) {
+            System.out.println("Jansi native library loaded from " + JansiLoader.getNativeLibraryPath());
+            if (JansiLoader.getNativeLibrarySourceUrl() != null) {
+                System.out.println("   which was auto-extracted from " + JansiLoader.getNativeLibrarySourceUrl());
+            }
+        } else {
+            String prev = System.getProperty(AnsiConsole.JANSI_GRACEFUL);
+            try {
+                System.setProperty(AnsiConsole.JANSI_GRACEFUL, "false");
+                JansiLoader.initialize();
+            } catch (Throwable e) {
+                e.printStackTrace(System.out);
+            } finally {
+                if (prev != null) {
+                    System.setProperty(AnsiConsole.JANSI_GRACEFUL, prev);
+                } else {
+                    System.clearProperty(AnsiConsole.JANSI_GRACEFUL);
+                }
+            }
         }
 
         System.out.println();
@@ -75,6 +91,7 @@ public static void main(String... args) throws IOException {
 
         System.out.println();
 
+        System.out.println(AnsiConsole.JANSI_GRACEFUL + "= " + System.getProperty(AnsiConsole.JANSI_GRACEFUL, ""));
         System.out.println(AnsiConsole.JANSI_MODE + "= " + System.getProperty(AnsiConsole.JANSI_MODE, ""));
         System.out.println(AnsiConsole.JANSI_OUT_MODE + "= " + System.getProperty(AnsiConsole.JANSI_OUT_MODE, ""));
         System.out.println(AnsiConsole.JANSI_ERR_MODE + "= " + System.getProperty(AnsiConsole.JANSI_ERR_MODE, ""));
@@ -171,7 +188,7 @@ private static String getJansiVersion() {
 
     private static void diagnoseTty(boolean stderr) {
         int fd = stderr ? CLibrary.STDERR_FILENO : CLibrary.STDOUT_FILENO;
-        int isatty = CLibrary.isatty(fd);
+        int isatty = CLibrary.LOADED ? CLibrary.isatty(fd) : 0;
 
         System.out.println("isatty(STD" + (stderr ? "ERR" : "OUT") + "_FILENO): " + isatty + ", System."
             + (stderr ? "err" : "out") + " " + ((isatty == 0) ? "is *NOT*" : "is") + " a terminal");

diff --git a/src/main/java/org/fusesource/jansi/internal/CLibrary.java b/src/main/java/org/fusesource/jansi/internal/CLibrary.java
@@ -26,13 +26,25 @@
 @SuppressWarnings("unused")
 public class CLibrary {
 
+    //
+    // Initialization
+    //
+
+    public static final boolean LOADED;
+
     static {
-        JansiLoader.initialize();
-        init();
+        LOADED = JansiLoader.initialize();
+        if (LOADED) {
+            init();
+        }
     }
 
     private static native void init();
 
+    //
+    // Constants
+    //
+
     public static int STDOUT_FILENO = 1;
 
     public static int STDERR_FILENO = 2;

diff --git a/src/main/java/org/fusesource/jansi/internal/JansiLoader.java b/src/main/java/org/fusesource/jansi/internal/JansiLoader.java
@@ -29,6 +29,8 @@
 import java.util.Properties;
 import java.util.Random;
 
+import org.fusesource.jansi.AnsiConsole;
+
 /**
  * Set the system properties, org.jansi.lib.path, org.jansi.lib.name,
  * appropriately so that jansi can find *.dll, *.jnilib and
@@ -41,7 +43,7 @@
  */
 public class JansiLoader {
 
-    private static boolean extracted = false;
+    private static boolean loaded = false;
     private static String nativeLibraryPath;
     private static String nativeLibrarySourceUrl;
 
@@ -53,15 +55,15 @@ public class JansiLoader {
      */
     public static synchronized boolean initialize() {
         // only cleanup before the first extract
-        if (!extracted) {
+        if (!loaded) {
             cleanup();
         }
         try {
             loadJansiNativeLibrary();
         } catch (Exception e) {
-            throw new RuntimeException("Unable to load jansi native library", e);
+            throw new RuntimeException("Unable to load jansi native library. You may want set the `jansi.graceful` system property to true to be able to use Jansi on your platform", e);
         }
-        return extracted;
+        return loaded;
     }
 
     public static String getNativeLibraryPath() {
@@ -263,7 +265,7 @@ private static boolean loadNativeLibrary(File libPath) {
      * @throws
      */
     private static void loadJansiNativeLibrary() throws Exception {
-        if (extracted) {
+        if (loaded) {
             return;
         }
 
@@ -283,14 +285,14 @@ private static void loadJansiNativeLibrary() throws Exception {
         if (jansiNativeLibraryPath != null) {
             String withOs = jansiNativeLibraryPath + "/" + OSInfo.getNativeLibFolderPathForCurrentOS();
             if (loadNativeLibrary(new File(withOs, jansiNativeLibraryName))) {
-                extracted = true;
+                loaded = true;
                 return;
             } else {
                 triedPaths.add(withOs);
             }
 
             if (loadNativeLibrary(new File(jansiNativeLibraryPath, jansiNativeLibraryName))) {
-                extracted = true;
+                loaded = true;
                 return;
             } else {
                 triedPaths.add(jansiNativeLibraryPath);
@@ -308,7 +310,7 @@ private static void loadJansiNativeLibrary() throws Exception {
             String tempFolder = getTempDir().getAbsolutePath();
             // Try extracting the library from jar
             if (extractAndLoadLibraryFile(jansiNativeLibraryPath, jansiNativeLibraryName, tempFolder)) {
-                extracted = true;
+                loaded = true;
                 return;
             } else {
                 triedPaths.add(jansiNativeLibraryPath);
@@ -322,16 +324,18 @@ private static void loadJansiNativeLibrary() throws Exception {
                 continue;
             }
             if (loadNativeLibrary(new File(ldPath, jansiNativeLibraryName))) {
-                extracted = true;
+                loaded = true;
                 return;
             } else {
                 triedPaths.add(ldPath);
             }
         }
 
-        extracted = false;
-        throw new Exception(String.format("No native library found for os.name=%s, os.arch=%s, paths=[%s]",
-                OSInfo.getOSName(), OSInfo.getArchName(), join(triedPaths, File.pathSeparator)));
+        loaded = false;
+        if (!Boolean.parseBoolean(System.getProperty(AnsiConsole.JANSI_GRACEFUL, "true"))) {
+            throw new Exception(String.format("No native library found for os.name=%s, os.arch=%s, paths=[%s]",
+                    OSInfo.getOSName(), OSInfo.getArchName(), join(triedPaths, File.pathSeparator)));
+        }
     }
 
     private static boolean hasResource(String path) {

diff --git a/src/main/java/org/fusesource/jansi/internal/Kernel32.java b/src/main/java/org/fusesource/jansi/internal/Kernel32.java
@@ -30,8 +30,9 @@
 public class Kernel32 {
 
     static {
-        JansiLoader.initialize();
-        init();
+        if (JansiLoader.initialize()) {
+            init();
+        }
     }
 
     private static native void init();