Some small, random fixes for JavaBuilder that increase error reporting, fix JavaDoc strings, ...

I found having stack traces very helpful while I was debugging an issue where the JavaBuilder ran out of file handles and crashed, but only printed "Compilation failed: No more file handles" and didn't tell me which part of the code actually tried to open the file.

--
MOS_MIGRATED_REVID=95529141

4 files changed, 9 insertions, 7 deletions

diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java
index 1ba28bf0bc..766d1f55e7 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java
@@ -13,7 +13,9 @@
 // limitations under the License.
 
 package com.google.devtools.build.buildjar;
+
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Throwables;
 import com.google.common.io.Files;
 import com.google.devtools.build.buildjar.javac.JavacRunner;
 import com.google.devtools.build.buildjar.javac.JavacRunnerImpl;
@@ -85,9 +87,7 @@ public abstract class AbstractJavaBuilder extends AbstractLibraryBuilder {
           } catch (JavacException e) {
             message[0] = e.getMessage();
           } catch (Exception e) {
-            // Some exceptions have a null message, yet the stack trace is useful
-            e.printStackTrace();
-            message[0] = "java compilation threw exception: " + e.getMessage();
+            message[0] = Throwables.getStackTraceAsString(e);
           }
         }
       }, 4L * 1024 * 1024);  // 4MB stack
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java
index 0ba15cd4fd..63d3cac13c 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java
@@ -102,8 +102,11 @@ public abstract class BazelJavaBuilder {
           ? new ReducedClasspathJavaLibraryBuilder()
           : new SimpleJavaLibraryBuilder();
       builder.run(build, System.err);
-    } catch (IOException | InvalidCommandLineException e) {
-      System.err.println(CMDNAME + " threw exception : " + e.getMessage());
+    } catch (InvalidCommandLineException e) {
+      System.err.println(CMDNAME + " threw exception: " + e.getMessage());
+      return 1;
+    } catch (IOException e) {
+      e.printStackTrace();
       return 1;
     }
     return 0;
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/JarCreator.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/JarCreator.java
index ead7ceb3dc..a233358263 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/JarCreator.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/JarCreator.java
@@ -191,7 +191,6 @@ public class JarCreator extends JarHelper {
       createJar.execute();
     } catch (IOException e) {
       e.printStackTrace();
-      System.err.println(e.getMessage());
       System.exit(1);
     }
     long stop = System.currentTimeMillis();
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/BlazeJavacMain.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/BlazeJavacMain.java
index eeb471c0bc..057c145a74 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/BlazeJavacMain.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/BlazeJavacMain.java
@@ -52,7 +52,7 @@ public class BlazeJavacMain {
    * Compose {@link com.sun.tools.javac.main.Main} and perform custom setup before deferring to
    * its compile() method.
    *
-   * Historically BlazeJavacMain extended javac's Main and overrode methods to get the desired
+   * <p>Historically BlazeJavacMain extended javac's Main and overrode methods to get the desired
    * custom behaviour. That approach created incompatibilities when upgrading to newer versions of
    * javac, so composition is preferred.
    */