Added a file parameter for file inclusion

README.md

@@ -126,6 +126,10 @@ Optional system properties:
       List of files to process, instead of processing all files.
       This is useful for a build tool to support incremental compilation.
 
+  retrolambda.includedFile
+      A file listing the files to process (one file per line), instead of processing all files.
+      This is useful for a build tool to support incremental compilation.
+
 If the Java agent is used, then Retrolambda will use it to capture the
 lambda classes generated by Java. Otherwise Retrolambda will hook into
 Java's internal lambda dumping API, which is more susceptible to suddenly

retrolambda/src/main/java/net/orfjackal/retrolambda/Config.java

@@ -4,9 +4,13 @@
 
 package net.orfjackal.retrolambda;
 
+import com.google.common.base.Charsets;
+import com.google.common.io.*;
+import com.google.common.io.Files;
 import org.objectweb.asm.Opcodes;
 
-import java.io.File;
+import java.io.*;
+import java.nio.charset.Charset;
 import java.nio.file.*;
 import java.util.*;
 import java.util.stream.Collectors;
@@ -20,6 +24,7 @@ public class Config {
     public static final String OUTPUT_DIR = PREFIX + "outputDir";
     public static final String CLASSPATH = PREFIX + "classpath";
     public static final String INCLUDED_FILES = PREFIX + "includedFiles";
+    public static final String INCLUDED_FILE = PREFIX + "includedFile";
 
     private static final List<String> requiredProperties = new ArrayList<>();
     private static final List<String> requiredPropertiesHelp = new ArrayList<>();
@@ -159,6 +164,29 @@ public List<Path> getIncludedFiles() {
                 .collect(Collectors.toList());
     }
 
+    static {
+        optionalParameterHelp(INCLUDED_FILE,
+                "A file listing the files to process (one file per line), instead of processing all files.",
+                "This is useful for a build tool to support incremental compilation.");
+    }
+
+    public List<Path> getIncludedFileList() {
+        String filePath = p.getProperty(INCLUDED_FILE);
+        if (filePath == null) {
+            return null;
+        }
+        File file = Paths.get(filePath).toFile();
+
+        try {
+            return Files.readLines(file, Charsets.UTF_8).stream()
+                    .filter(s -> !s.isEmpty())
+                    .map(Paths::get)
+                    .collect(Collectors.toList());
+        } catch (IOException e) {
+            return Collections.emptyList();
+        }
+    }
+
     // help
 
     public String getHelp() {

retrolambda/src/main/java/net/orfjackal/retrolambda/Retrolambda.java

@@ -4,6 +4,7 @@
 
 package net.orfjackal.retrolambda;
 
+import com.google.common.collect.Lists;
 import net.orfjackal.retrolambda.files.*;
 import net.orfjackal.retrolambda.interfaces.*;
 import net.orfjackal.retrolambda.lambdas.*;
@@ -21,13 +22,23 @@ public static void run(Config config) throws Throwable {
         Path inputDir = config.getInputDir();
         Path outputDir = config.getOutputDir();
         String classpath = config.getClasspath();
-        List<Path> includedFiles = config.getIncludedFiles();
+        List<Path> includedFilesByArgument = config.getIncludedFileList();
+        List<Path> includedFilesByFileList = config.getIncludedFiles();
+
         System.out.println("Bytecode version: " + bytecodeVersion + " (" + config.getJavaVersion() + ")");
         System.out.println("Default methods:  " + defaultMethodsEnabled);
         System.out.println("Input directory:  " + inputDir);
         System.out.println("Output directory: " + outputDir);
         System.out.println("Classpath:        " + classpath);
-        if (includedFiles != null) {
+
+        List<Path> includedFiles  = Lists.newArrayList();
+        if (includedFilesByArgument != null) {
+            includedFiles.addAll(includedFilesByArgument);
+        }
+        if (includedFilesByFileList != null) {
+            includedFiles.addAll(includedFilesByFileList);
+        }
+        if (!includedFiles.isEmpty()) {
             System.out.println("Included files:   " + includedFiles.size());
         }
 

retrolambda/src/test/java/net/orfjackal/retrolambda/ConfigTest.java

@@ -4,12 +4,17 @@
 
 package net.orfjackal.retrolambda;
 
+import com.google.common.base.*;
+import com.google.common.collect.Lists;
+import com.google.common.io.Files;
 import org.junit.*;
 import org.junit.rules.ExpectedException;
 
-import java.io.File;
+import java.io.*;
 import java.nio.file.Paths;
 import java.util.*;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.*;
@@ -72,4 +77,41 @@ public void included_files() {
         systemProperties.setProperty(Config.INCLUDED_FILES, "/foo/one.class" + File.pathSeparator + "/foo/two.class");
         assertThat("multiple values", config().getIncludedFiles(), is(Arrays.asList(Paths.get("/foo/one.class"), Paths.get("/foo/two.class"))));
     }
-}
+
+    @Test
+    public void included_file() throws IOException {
+        assertThat("not set", config().getIncludedFileList(), is(nullValue()));
+
+        systemProperties.setProperty(Config.INCLUDED_FILE, "");
+        assertThat("zero values", config().getIncludedFileList(), is(empty()));
+
+        // Single file
+        File singleTmp = File.createTempFile("test",".list");
+        singleTmp.deleteOnExit();
+
+        List<String> file = Lists.newArrayList("foo.java");
+        String delimiter = System.getProperty("line.separator");
+        Files.write(file.stream()
+                .collect(Collectors.joining(delimiter)), singleTmp, Charsets.UTF_8);
+
+        systemProperties.setProperty(Config.INCLUDED_FILE, singleTmp.getAbsolutePath());
+        assertThat("one value", config().getIncludedFileList(), is(
+                file.stream()
+                        .map(f -> Paths.get(f))
+                        .collect(Collectors.toList())));
+
+        // Multiple files
+        File multiTmp = File.createTempFile("test",".list");
+        multiTmp.deleteOnExit();
+
+        List<String> files = Lists.newArrayList("foo.java", "bar.java");
+        Files.write(files.stream()
+                .collect(Collectors.joining(delimiter)), multiTmp, Charsets.UTF_8);
+
+        systemProperties.setProperty(Config.INCLUDED_FILE, multiTmp.getAbsolutePath());
+        assertThat("two values", config().getIncludedFileList(), is(
+                files.stream()
+                        .map(f -> Paths.get(f))
+                        .collect(Collectors.toList())));
+    }
+}