您需要在编译器类路径中包含输出目录。请注意我是如何在下面的类路径中包含 targetDirectory 的：
/**
* Compiles Java source-code.
* <p/>
* @author Gili Tzabari
*/
public final class JavaCompiler
{
private List<Path> sourcePath = new ArrayList<>();
private List<Path> classPath = new ArrayList<>();
private final Set<DebugType> debugOptions = new HashSet<>(Arrays.asList(DebugType.LINES,
DebugType.SOURCE, DebugType.VARIABLES));
/**
* Sets the compiler classpath.
* <p/>
* @param sourcePath the paths to search for the source format of dependent classes
* @throws NullPointerException if sourcePath is null
* @throws IllegalArgumentException if sourcePath refers to a non-existent path or a non-directory
* @return the JavaCompiler
*/
public JavaCompiler sourcePath(List<Path> sourcePath)
{
Preconditions.checkNotNull(sourcePath, "sourcePath may not be null");
for (Path path: sourcePath)
{
if (!Files.exists(path))
{
throw new IllegalArgumentException("sourcePath refers to non-existant path: " + path.
toAbsolutePath());
}
if (!Files.isDirectory(path))
{
throw new IllegalArgumentException("sourcePath refers to a non-directory: " + path.
toAbsolutePath());
}
}
this.sourcePath = ImmutableList.copyOf(sourcePath);
return this;
}
/**
* Sets the compiler classpath.
* <p/>
* @param classPath the paths to search for the compiled format of dependent classes
* @throws NullPointerException if classPath is null
* @throws IllegalArgumentException if classPath refers to a non-existent path
* @return the JavaCompiler
*/
public JavaCompiler classPath(List<Path> classPath)
{
Preconditions.checkNotNull(classPath, "classPath may not be null");
for (Path path: classPath)
{
if (!Files.exists(path))
{
throw new IllegalArgumentException("classPath refers to non-existant path: " + path.
toAbsolutePath());
}
}
this.classPath = ImmutableList.copyOf(classPath);
return this;
}
/**
* Indicates the kind of debugging information the generated files should contain.
* <p/>
* @param debugOptions the kind of debugging information the generated files should contain. By
* default all debugging information is generated.
* @return the JavaCompiler object
*/
public JavaCompiler debug(DebugType... debugOptions)
{
this.debugOptions.clear();
this.debugOptions.addAll(Arrays.asList(debugOptions));
return this;
}
/**
* Compiles the source code.
* <p/>
* @param sourceFiles the source files to compile
* @param targetDirectory the directory to compile into. This path included in the compiler
* classpath.
* @throws IllegalArgumentException if sourceFiles, targetDirectory are null; or if sourceFiles
* refers to a non-existent file or a non-file; or if targetDirectory is not a directory
* @throws CompilationException if the operation fails
*/
public void run(final Collection<Path> sourceFiles, final Path targetDirectory)
throws IllegalArgumentException, CompilationException
{
if (sourceFiles == null)
throw new IllegalArgumentException("sourceFiles may not be null");
if (sourceFiles.isEmpty())
return;
for (Path file: sourceFiles)
{
if (!Files.exists(file))
{
throw new IllegalArgumentException("sourceFiles refers to a non-existant file: "
+ file.toAbsolutePath());
}
if (!Files.isRegularFile(file))
{
throw new IllegalArgumentException("sourceFiles refers to a non-file: "
+ file.toAbsolutePath());
}
}
if (targetDirectory == null)
throw new IllegalArgumentException("targetDirectory may not be null");
if (!Files.exists(targetDirectory))
{
throw new IllegalArgumentException("targetDirectory must exist: " + targetDirectory.
toAbsolutePath());
}
if (!Files.isDirectory(targetDirectory))
{
throw new IllegalArgumentException("targetDirectory must be a directory: " + targetDirectory.
toAbsolutePath());
}
Set<Path> uniqueSourceFiles = ImmutableSet.copyOf(sourceFiles);
Set<Path> uniqueSourcePath = ImmutableSet.copyOf(sourcePath);
final javax.tools.JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (compiler == null)
{
throw new AssertionError("javax.tools.JavaCompiler is not available. Is tools.jar missing "
+ "from the classpath?");
}
final DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<>();
final StandardJavaFileManager fileManager = compiler.getStandardFileManager(diagnostics, null,
null);
Iterable<? extends JavaFileObject> compilationUnits;
try
{
Set<File> modifiedFiles = getModifiedFiles(uniqueSourceFiles, uniqueSourcePath,
targetDirectory, new HashSet<Path>());
if (modifiedFiles.isEmpty())
return;
compilationUnits = fileManager.getJavaFileObjectsFromFiles(modifiedFiles);
}
catch (IOException e)
{
throw new CompilationException(e);
}
final List<Path> effectiveClasspath = new ArrayList<>();
effectiveClasspath.add(targetDirectory);
effectiveClasspath.addAll(classPath);
final List<String> options = new ArrayList<>();
options.add("-cp");
options.add(Joiner.on(File.pathSeparatorChar).join(effectiveClasspath));
final StringBuilder debugLine = new StringBuilder("-g:");
for (DebugType type: debugOptions)
{
switch (type)
{
case LINES:
{
debugLine.append("lines,");
break;
}
case SOURCE:
{
debugLine.append("source,");
break;
}
case VARIABLES:
{
debugLine.append("vars,");
break;
}
default:
throw new AssertionError(type);
}
}
if (!debugOptions.isEmpty())
{
debugLine.deleteCharAt(debugLine.length() - ",".length());
options.add(debugLine.toString());
}
if (!uniqueSourcePath.isEmpty())
{
options.add("-sourcepath");
options.add(Joiner.on(File.pathSeparatorChar).join(uniqueSourcePath));
}
options.add("-s");
options.add(targetDirectory.toString());
options.add("-d");
options.add(targetDirectory.toString());
final Writer output = null;
final CompilationTask task = compiler.getTask(output, fileManager, diagnostics, options, null,
compilationUnits);
final boolean result = task.call();
try
{
printDiagnostics(diagnostics, options, sourceFiles);
}
catch (IOException e)
{
throw new BuildException(e);
}
if (!result)
throw new CompilationException();
try
{
fileManager.close();
}
catch (IOException e)
{
throw new BuildException(e);
}
}
/**
* Returns the java source-code file corresponding to a class name.
* <p/>
* @param className the fully-qualified class name to look up
* @param sourcePath the source-code search path
* @return null if no match was found
*/
private static File getJavaSource(String className, Set<File> sourcePath)
{
// TODO: check for class files instead of source
for (File path: sourcePath)
{
File result = classNameToFile(path, className);
if (!result.exists())
continue;
return result;
}
return null;
}
/**
* Converts a class name to its source-code file.
* <p/>
* @param sourcePath the source-code search path
* @param className the fully-qualified class name
* @return the source-code file
*/
private static File classNameToFile(File sourcePath, String className)
{
return new File(sourcePath, className.replace(".", "/") + ".java");
}
/**
* Displays any compilation errors.
* <p/>
* @param diagnostics the compiler diagnostics
* @param options the command-line options passed to the compiler
* @param sourceFiles the source files to compile
* @throws IOException if an I/O error occurs
*/
private void printDiagnostics(final DiagnosticCollector<JavaFileObject> diagnostics,
final List<String> options, final Collection<Path> sourceFiles) throws IOException
{
Logger log = LoggerFactory.getLogger(JavaCompiler.class.getName() + ".stderr");
int errors = 0;
int warnings = 0;
boolean firstTime = true;
for (Diagnostic<? extends JavaFileObject> diagnostic: diagnostics.getDiagnostics())
{
if (firstTime)
{
firstTime = false;
StringBuilder message = new StringBuilder();
message.append("Invoking: javac ");
for (String token: options)
message.append(token).append(" ");
message.append(Joiner.on(" ").join(sourceFiles));
log.debug(message.toString());
}
JavaFileObject source = diagnostic.getSource();
if (source == null)
log.error(diagnostic.getMessage(null));
else
{
StringBuilder message = new StringBuilder();
message.append(source.getName());
if (diagnostic.getLineNumber() != Diagnostic.NOPOS)
message.append(":").append(diagnostic.getLineNumber());
message.append(": ").append(diagnostic.getMessage(null));
log.error(message.toString());
try (BufferedReader reader =
new BufferedReader(new InputStreamReader(source.openInputStream())))
{
String line = null;
for (long lineNumber = 0, size = diagnostic.getLineNumber(); lineNumber < size;
++lineNumber)
{
line = reader.readLine();
if (line == null)
break;
}
if (line != null)
{
log.error(line);
message = new StringBuilder();
for (long i = 1, size = diagnostic.getColumnNumber(); i < size; ++i)
message.append(" ");
message.append("^");
log.error(message.toString());
}
}
}
switch (diagnostic.getKind())
{
case ERROR:
{
++errors;
break;
}
case NOTE:
case OTHER:
case WARNING:
case MANDATORY_WARNING:
{
++warnings;
break;
}
default:
throw new AssertionError(diagnostic.getKind());
}
}
if (errors > 0)
{
StringBuilder message = new StringBuilder();
message.append(errors).append(" error");
if (errors > 1)
message.append("s");
log.error(message.toString());
}
if (warnings > 0)
{
StringBuilder message = new StringBuilder();
message.append(warnings).append(" warning");
if (warnings > 1)
message.append("s");
log.warn(message.toString());
}
}
/**
* Returns the source-code files that have been modified.
* <p/>
* @param sourceFiles the source files to process
* @param sourcePath the source file search path
* @param targetDirectory the directory to compile into
* @param unmodifiedFiles files that are known not to have been modified
* @return all changed source-code files that are accepted by the filter
* @throws IOException if an I/O error occurs
*/
private Set<File> getModifiedFiles(final Set<Path> sourceFiles,
final Set<Path> sourcePath, final Path targetDirectory, final Set<Path> unmodifiedFiles)
throws IOException
{
// TODO: Right now all files are assumed to have been modified
Set<File> result = new HashSet<>();
for (Path path: sourceFiles)
result.add(path.toFile());
return result;
}
/**
* Returns the command-line representation of the object.
* <p/>
* @param sourceFiles the source files to compile
* @param targetDirectory the directory to compile into
* @param sourcePath the source file search path
* @return the command-line representation of the object
* @throws IllegalArgumentException if the classpath contains non-file components
* @throws IOException if an I/O error occurs
*/
private List<String> toCommandLine(final Collection<Path> sourceFiles, final Path targetDirectory,
final Collection<Path> sourcePath)
throws IOException
{
final List<String> result = Lists.newArrayList("javac");
if (!classPath.isEmpty())
{
result.add("-cp");
try
{
final StringBuilder line = new StringBuilder();
for (final Iterator<Path> i = classPath.iterator(); i.hasNext();)
{
line.append(i.next().getParent().toString());
if (i.hasNext())
line.append(File.pathSeparatorChar);
}
result.add(line.toString());
}
catch (IllegalArgumentException e)
{
// Occurs if URL does not refer to a file
throw new IllegalStateException(e);
}
}
for (File javaFile: getModifiedFiles(ImmutableSet.copyOf(sourceFiles),
ImmutableSet.copyOf(sourcePath), targetDirectory, new HashSet<Path>()))
{
result.add(javaFile.getPath());
}
result.add("-d");
result.add(targetDirectory.getParent().toString());
return result;
}
@Override
public String toString()
{
return getClass().getName() + "[classPath=" + classPath + "]";
}
/**
* The type of debugging information that generated files may contain.
* <p/>
* @author Gili Tzabari
*/
@SuppressWarnings("PublicInnerClass")
public enum DebugType
{
/**
* No debugging information.
*/
NONE,
/**
* Line number information.
*/
LINES,
/**
* Local variable information.
*/
VARIABLES,
/**
* Source file information.
*/
SOURCE
}
}