Lots of API changes, move from nulls to throwing exceptions

Author: Jonathing

build.gradle

@@ -49,6 +49,8 @@ tasks.register('javaProbeJar', Jar) {
 }
 
 dependencies {
+    compileOnly libs.nulls
+
     implementation libs.jopt
     implementation libs.gson
     implementation libs.jtar

settings.gradle

@@ -14,6 +14,8 @@ dependencyResolutionManagement {
         plugin 'gradleutils', 'net.minecraftforge.gradleutils' version '2.6.0'
         plugin 'shadow', 'com.gradleup.shadow' version '9.0.0-beta13'
 
+        library 'nulls', 'org.jetbrains:annotations:26.0.2-1'
+
         library 'gson', 'com.google.code.gson:gson:2.10.1'           // > 2.9.0 needs Java 7
         library 'jopt', 'net.sf.jopt-simple:jopt-simple:6.0-alpha-3' // Java 8
         library 'jtar', 'org.kamranzafar:jtar:2.3'

src/main/java/net/minecraftforge/java_provisioner/Disco.java

@@ -6,13 +6,13 @@
 
 import java.io.File;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
-import net.minecraftforge.java_provisioner.Disco.Arch;
 import net.minecraftforge.java_provisioner.Disco.Distro;
 import net.minecraftforge.java_provisioner.api.IJavaInstall;
-import net.minecraftforge.util.os.OS;
+import net.minecraftforge.java_provisioner.api.JavaLocatingFailedException;
+import net.minecraftforge.java_provisioner.api.JavaProvisioningFailedException;
 
 /**
  * Locates java installs that have been downloaded from the <a href="https://github.com/foojayio/discoapi">disco API</a>
@@ -44,45 +44,50 @@ public DiscoLocator(File cache, boolean offline) {
     }
 
     @Override
-    public File find(int version) {
-        List<IJavaInstall> results = findInternal(version);
-        return results.isEmpty() ? null : results.get(0).home();
+    public File find(int version) throws JavaLocatingFailedException {
+        return findInternal(version).installs().get(0).home();
     }
 
     @Override
-    public List<IJavaInstall> findAll() {
+    public JavaLocatorResult findAll() throws JavaLocatingFailedException {
         return findInternal(-1);
     }
 
-    private List<IJavaInstall> findInternal(int version) {
+    private JavaLocatorResult findInternal(int version) throws JavaLocatingFailedException {
         if (!cache.exists() || !cache.isDirectory())
-            return Collections.emptyList();
+            throw new JavaLocatingFailedException("Java Provisioner has not provisioned any Java installations");
 
         List<IJavaInstall> results = new ArrayList<>();
-        for (File dir : cache.listFiles()) {
+        List<Throwable> errors = new ArrayList<>();
+
+        File[] listFiles;
+        try {
+            listFiles = Objects.requireNonNull(cache.listFiles());
+        } catch (Exception e) {
+            throw new JavaLocatingFailedException("An unexpected error occured trying to query the Disco cache: " + cache, e);
+        }
+
+        for (File dir : listFiles) {
             if (!dir.isDirectory())
                 continue;
 
             log("Disco Cache: \"" + dir.getAbsolutePath() + "\"");
 
-            IJavaInstall ret = fromPath(dir);
-            if (ret != null) {
-                if (version == -1) {
-                    results.add(ret);
-                } else if (ret.majorVersion() != version) {
-                    log("  Wrong version: Was " + ret.majorVersion() + " wanted " + version);
-                } else {
-                    results.add(ret);
-                    return results;
-                }
+            try {
+                results.add(fromPath(dir, version));
+            } catch (Exception e) {
+                errors.add(e);
             }
         }
 
-        return results;
+        if (!results.isEmpty())
+            return new JavaLocatorResult(results, errors);
+
+        throw Throwing.provisioningFailed("Failed to find any Java installations from Disco cache", errors);
     }
 
     @Override
-    public IJavaInstall provision(int version) {
+    public IJavaInstall provision(int version, Distro distro) throws JavaProvisioningFailedException {
         log("Locators failed to find any suitable installs, attempting Disco download");
         Disco disco = new Disco(cache, offline) { // TODO: [DISCO][Logging] Add a proper logging handler sometime
             @Override
@@ -96,34 +101,31 @@ protected void error(String message) {
             }
         };
 
-        List<Disco.Package> jdks = disco.getPackages(version, Disco.CURRENT_OS, Distro.TEMURIN, Disco.CURRENT_ARCH);
-        if (jdks == null || jdks.isEmpty()) {
-            log("Failed to find any distros from Disco for " + version + " " + Disco.CURRENT_OS + " " + Disco.CURRENT_ARCH + " " + Distro.TEMURIN);
-
-            // Try any vendor
-            jdks = disco.getPackages(version, Disco.CURRENT_OS, null, Disco.CURRENT_ARCH);
-            if (jdks == null || jdks.isEmpty()) {
-                log("Failed to find any distros from Disco for " + version + " " + Disco.CURRENT_OS + " " + Disco.CURRENT_ARCH);
-
-                // Try any Architecture and just hope for the best
-                jdks = disco.getPackages(version, Disco.CURRENT_OS, null, null);
-                if (jdks == null || jdks.isEmpty()) {
-                    log("Failed to find any distros from Disco for " + version + " " + Disco.CURRENT_OS);
-                    return null;
-                }
+        List<Disco.Package> jdks;
+        try {
+            jdks = disco.getPackages(version, Disco.CURRENT_OS, distro, Disco.CURRENT_ARCH);
+        } catch (Exception e) {
+            log(String.format("Failed to find any JDKs from Disco for: %s%d - %s %s", distro != null ? distro + " " : "", version, Disco.CURRENT_OS, Disco.CURRENT_ARCH));
+
+            // Try any Architecture and just hope for the best
+            try {
+                jdks = disco.getPackages(version, Disco.CURRENT_OS, distro, null);
+            } catch (Exception suppressed) {
+                log(String.format("Failed to find any JDKs from Disco for: %s%d - %s ANY", distro != null ? distro + " " : "", version, Disco.CURRENT_OS));
+                e.addSuppressed(suppressed);
+                throw new JavaProvisioningFailedException("Failed to provision Disco download", e);
             }
         }
 
-        log("Found " + jdks.size() + " download canidates");
+        log("Found " + jdks.size() + " download candidates");
         Disco.Package pkg = jdks.get(0);
         log("Selected " + pkg.distribution + ": " + pkg.filename);
 
-        File java_home = disco.extract(pkg);
-
-        if (java_home == null)
-            return null;
-
-        IJavaInstall result = fromPath(java_home);
-        return result;
+        try {
+            File java_home = disco.extract(pkg);
+            return fromPath(java_home);
+        } catch (Exception e) {
+            throw new JavaProvisioningFailedException("Failed to provision Disco download: " + pkg.filename, e);
+        }
     }
 }

src/main/java/net/minecraftforge/java_provisioner/DiscoLocator.java

@@ -100,12 +100,17 @@ private static boolean downloadJdk(
         Log.info("    Cache:   " + cache.getAbsolutePath());
         Disco disco = new Disco(new File(cache, "jdks"));
 
-        List<Disco.Package> jdks = disco.getPackages(javaVersion, os, distro, arch);
-        Disco.Package pkg = null;
-        if (jdks == null || jdks.isEmpty()) {
+        List<Disco.Package> jdks;
+        try {
+            jdks = disco.getPackages(javaVersion, os, distro, arch);
+            if (jdks.isEmpty())
+                throw new Exception("No download found");
+        } catch (Exception e) {
             Log.error("Failed to find any download, try specifying a different java version or distro");
             return false;
-        } else if (jdks.size() == 1 || auto) {
+        }
+        Disco.Package pkg = null;
+        if (jdks.size() == 1 || auto) {
             pkg = jdks.get(0);
         } else if (jdks.size() > 1) {
             for (int x = 0; x < jdks.size(); x++) {
@@ -135,10 +140,16 @@ private static boolean downloadJdk(
 
         Log.info();
 
-        File java_home = disco.extract(pkg);
+        File java_home;
+        try {
+            java_home = disco.extract(pkg);
+        } catch (Exception e) {
+            throw new RuntimeException("Failed to extract downloaded package", e);
+        }
 
-        if (java_home == null)
-            System.exit(1);
+        // No longer needed as we throw if no java home, but just in case:
+        //if (java_home == null)
+        //    System.exit(1);
 
         ProcessUtils.Result result = ProcessUtils.testJdk(java_home);
         if (result.exitCode != 0) {