Fix issue #35: Allow to ignore empty filesets: <forbiddenapis ignoreE…

…mptyFileset="true"/>.

Fix issue #36: Allow signaturesFileList and signaturesFile nested elements to enforce existence (does not work with Filesets).

src/main/java/de/thetaphi/forbiddenapis/AntTask.java

@@ -23,6 +23,7 @@
 import org.apache.tools.ant.Project;
 import org.apache.tools.ant.Task;
 import org.apache.tools.ant.types.Path;
+import org.apache.tools.ant.types.FileList;
 import org.apache.tools.ant.types.FileSet;
 import org.apache.tools.ant.types.Reference;
 import org.apache.tools.ant.types.Resource;
@@ -55,6 +56,7 @@ public final class AntTask extends Task {
   private boolean internalRuntimeForbidden = false;
   private boolean restrictClassFilename = true;
   private boolean failOnMissingClasses = true;
+  private boolean ignoreEmptyFileset = false;
 
   @Override
   public void execute() throws BuildException {
@@ -112,12 +114,9 @@ protected void logInfo(String msg) {
         }
 
         @SuppressWarnings("unchecked")
-        Iterator<Resource> iter = (Iterator<Resource>) apiSignatures.iterator();
+        final Iterator<Resource> iter = (Iterator<Resource>) apiSignatures.iterator();
         while (iter.hasNext()) {
           final Resource r = iter.next();
-          if (!r.isExists()) { 
-            throw new BuildException("Signatures file does not exist: " + r);
-          }
           if (r instanceof StringResource) {
             final String s = ((StringResource) r).getValue();
             if (s != null && s.trim().length() > 0) {
@@ -142,23 +141,28 @@ protected void logInfo(String msg) {
       log("Loading classes to check...", Project.MSG_INFO);
       try {
         @SuppressWarnings("unchecked")
-        Iterator<Resource> iter = (Iterator<Resource>) classFiles.iterator();
-        if (!iter.hasNext()) {
-          throw new BuildException("There is no <fileset/> given or the fileset does not contain any class files to check.");
-        }
+        final Iterator<Resource> iter = (Iterator<Resource>) classFiles.iterator();
+        boolean foundClass = false;
         while (iter.hasNext()) {
           final Resource r = iter.next();
           final String name = r.getName();
           if (restrictClassFilename && name != null && !name.endsWith(".class")) {
             continue;
           }
-          if (!r.isExists()) { 
-            throw new BuildException("Class file does not exist: " + r);
-          }
           checker.addClassToCheck(r.getInputStream());
+          foundClass = true;
+        }
+        if (!foundClass) {
+          if (ignoreEmptyFileset) {
+            log("There is no <fileset/> or other resource collection given, or the collection does not contain any class files to check.", Project.MSG_WARN);
+            log("Scanned 0 class files.", Project.MSG_INFO);
+            return;
+          } else {
+            throw new BuildException("There is no <fileset/> or other resource collection given, or the collection does not contain any class files to check.");
+          }
         }
       } catch (IOException ioe) {
-        throw new BuildException("Failed to load one of the given class files:" + ioe);
+        throw new BuildException("Failed to load one of the given class files: " + ioe);
       }
 
       log("Scanning for API signatures and dependencies...", Project.MSG_INFO);
@@ -202,6 +206,22 @@ public FileSet createSignaturesFileSet() {
     return fs;
   }
 
+  /** List of files with API signatures as <signaturesFileList/> nested element */
+  public FileList createSignaturesFileList() {
+    final FileList fl = new FileList();
+    fl.setProject(getProject());
+    apiSignatures.add(fl);
+    return fl;
+  }
+
+  /** Single file with API signatures as <signaturesFile/> nested element */
+  public FileResource createSignaturesFile() {
+    final FileResource fr = new FileResource();
+    fr.setProject(getProject());
+    apiSignatures.add(fr);
+    return fr;
+  }
+
   public BundledSignaturesType createBundledSignatures() {
     final BundledSignaturesType s = new BundledSignaturesType();
     s.setProject(getProject());
@@ -278,4 +298,11 @@ public void setRestrictClassFilename(boolean restrictClassFilename) {
     this.restrictClassFilename = restrictClassFilename;
   }
 
+  /** Ignore empty fileset/resource collection and print a warning instead.
+   * Defaults to {@code false}.
+   */
+  public void setIgnoreEmptyFileSet(boolean ignoreEmptyFileset) {
+    this.ignoreEmptyFileset = ignoreEmptyFileset;
+  }
+
 }

src/test/antunit/TestClassReferences.xml

@@ -19,7 +19,7 @@
   <target name="testClassReferences">
     <au:expectfailure expectedMessage="Check for forbidden API calls failed, see log">
       <forbiddenapis>
-        <fileset file="Java5ClassReferences.class"/>
+        <file file="Java5ClassReferences.class"/>
         java.lang.Integer @ Forbidden class reference!
         java.util.List @ Forbidden class reference!
         java.util.AbstractCollection @ Forbidden class reference!

src/test/antunit/TestCommonsIOSignatures.xml

@@ -32,13 +32,7 @@
     <echo message="Testing signatures of version ${commons-io-version}..."/>
     <ivy:cachepath organisation="commons-io" module="commons-io" revision="${commons-io-version}"
       inline="true" conf="master" type="jar" pathid="commons-io.classpath" log="${ivy.logging}"/> 
-    <forbiddenapis bundledSignatures="${commons-io-signature}">
-      <classpath>
-        <path refid="path.run"/>
-        <path refid="commons-io.classpath"/>
-      </classpath>
-      <fileset refid="main.classes"/>
-    </forbiddenapis>
+    <forbiddenapis bundledSignatures="${commons-io-signature}" ignoreEmptyFileset="true" classpathref="commons-io.classpath"/>
   </target>
 
 </project>

src/test/antunit/TestFileSignatures.xml

@@ -37,4 +37,24 @@
     <au:assertLogContains level="error" text="java.lang.String#substring(int,int) [You are crazy that you disallow substrings]"/> 
   </target>
 
+  <target name="testFileList">
+    <au:expectfailure expectedMessage="Check for forbidden API calls failed, see log">
+      <forbiddenapis classpathref="path.run">
+        <fileset refid="main.classes"/>
+        <signaturesFilelist dir="." files="signatures1.txt"/>
+      </forbiddenapis>
+    </au:expectfailure>
+    <au:assertLogContains level="error" text="java.lang.String#substring(int,int) [You are crazy that you disallow substrings]"/> 
+  </target>
+
+  <target name="testFileResource">
+    <au:expectfailure expectedMessage="Check for forbidden API calls failed, see log">
+      <forbiddenapis classpathref="path.run">
+        <fileset refid="main.classes"/>
+        <signaturesFile file="signatures1.txt"/>
+      </forbiddenapis>
+    </au:expectfailure>
+    <au:assertLogContains level="error" text="java.lang.String#substring(int,int) [You are crazy that you disallow substrings]"/> 
+  </target>
+
 </project>

src/test/antunit/TestInternalRuntimeCalls.xml

@@ -19,7 +19,7 @@
   <target name="testInternalRuntimeForbidden">
     <au:expectfailure expectedMessage="Check for forbidden API calls failed, see log">
       <forbiddenapis internalRuntimeForbidden="true" failOnMissingClasses="false">
-        <fileset file="OracleInternalRuntime.class"/>
+        <file file="OracleInternalRuntime.class"/>
       </forbiddenapis>
     </au:expectfailure>
     <au:assertLogContains level="error" text="sun.misc.BASE64Encoder [non-public internal runtime class]"/> 

src/test/antunit/TestJava8.xml

@@ -19,7 +19,7 @@
   <target name="testDefaultMethodAndClosures">
     <au:expectfailure expectedMessage="Check for forbidden API calls failed, see log">
       <forbiddenapis failOnMissingClasses="false">
-        <fileset file="Java8Closures.class"/>
+        <file file="Java8Closures.class"/>
         java.io.Closeable @ Police alarm!
         java.lang.StringBuilder @ Police alarm!
         java.lang.Integer#compareTo(java.lang.Integer) @ Closure alarm!