classlib: Add nio's channel interfaces (#751)

- Add the basic java.nio.channels.Channel interfaces.
 - Add several nio exception types.
 - Add UncheckedIOException

classlib/src/main/java/org/teavm/classlib/java/io/TUncheckedIOException.java

@@ -0,0 +1,15 @@
+package org.teavm.classlib.java.io;
+
+import java.io.IOException;
+
+public class TUncheckedIOException extends RuntimeException {
+    private static final long serialVersionUID = 1645785175445590213L;
+
+    public TUncheckedIOException(IOException cause) {
+        super(cause);
+    }
+
+    public TUncheckedIOException(String message, IOException cause) {
+        super(message, cause);
+    }
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TByteChannel.java

@@ -0,0 +1,4 @@
+package org.teavm.classlib.java.nio.channels;
+
+public interface TByteChannel extends TReadableByteChannel, TWritableByteChannel {
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TChannel.java

@@ -0,0 +1,11 @@
+package org.teavm.classlib.java.nio.channels;
+
+import org.teavm.classlib.java.io.TCloseable;
+
+import java.io.IOException;
+
+public interface TChannel extends TCloseable {
+    boolean isOpen();
+
+    void close() throws IOException;
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TClosedChannelException.java

@@ -0,0 +1,7 @@
+package org.teavm.classlib.java.nio.channels;
+
+import java.io.IOException;
+
+public class TClosedChannelException extends IOException {
+    private static final long serialVersionUID = 5928119801967419918L;
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TNonReadableChannelException.java

@@ -0,0 +1,5 @@
+package org.teavm.classlib.java.nio.channels;
+
+public class TNonReadableChannelException extends IllegalStateException {
+    private static final long serialVersionUID = -2344456823086925506L;
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TNonWritableChannelException.java

@@ -0,0 +1,5 @@
+package org.teavm.classlib.java.nio.channels;
+
+public class TNonWritableChannelException extends IllegalStateException {
+    private static final long serialVersionUID = -837317372114923332L;
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TReadableByteChannel.java

@@ -0,0 +1,9 @@
+package org.teavm.classlib.java.nio.channels;
+
+import org.teavm.classlib.java.nio.TByteBuffer;
+
+import java.io.IOException;
+
+public interface TReadableByteChannel extends TChannel {
+    int read(TByteBuffer dst) throws IOException;
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TSeekableByteChannel.java

@@ -0,0 +1,13 @@
+package org.teavm.classlib.java.nio.channels;
+
+import java.io.IOException;
+
+public interface TSeekableByteChannel extends TByteChannel {
+    long position();
+
+    TSeekableByteChannel position(long newPosition) throws IOException;
+
+    long size() throws IOException;
+
+    TSeekableByteChannel truncate(long size) throws IOException;
+}

classlib/src/main/java/org/teavm/classlib/java/nio/channels/TWritableByteChannel.java

@@ -0,0 +1,9 @@
+package org.teavm.classlib.java.nio.channels;
+
+import org.teavm.classlib.java.nio.TByteBuffer;
+
+import java.io.IOException;
+
+public interface TWritableByteChannel extends TChannel {
+    int write(TByteBuffer src) throws IOException;
+}

classlib/src/main/java/org/teavm/classlib/java/nio/file/TAccessDeniedException.java

@@ -0,0 +1,13 @@
+package org.teavm.classlib.java.nio.file;
+
+public class TAccessDeniedException extends TFileSystemException {
+    private static final long serialVersionUID = 6428707745039365878L;
+
+    public TAccessDeniedException(String file) {
+        super(file);
+    }
+
+    public TAccessDeniedException(String file, String other, String reason) {
+        super(file, other, reason);
+    }
+}

classlib/src/main/java/org/teavm/classlib/java/nio/file/TFileSystemException.java

@@ -0,0 +1,47 @@
+package org.teavm.classlib.java.nio.file;
+
+import java.io.IOException;
+
+public class TFileSystemException extends IOException {
+    private static final long serialVersionUID = 9093298181737952280L;
+
+    private final String file;
+    private final String other;
+    private final String reason;
+
+    public TFileSystemException(String file) {
+        this.file = file;
+        this.other = null;
+        this.reason = null;
+    }
+
+    public TFileSystemException(String file, String other, String reason) {
+        super(reason);
+        this.file = file;
+        this.other = other;
+        this.reason = reason;
+    }
+
+    public String getFile() {
+        return file;
+    }
+
+    public String getOtherFile() {
+        return other;
+    }
+
+    public String getReason() {
+        return reason;
+    }
+
+    @Override
+    public String getMessage() {
+        if (file == null && other == null) return reason;
+
+        StringBuilder out = new StringBuilder();
+        if (file != null) out.append(file);
+        if (other != null) out.append(" -> ").append(other);
+        if (reason != null) out.append(": ").append(reason);
+        return out.toString();
+    }
+}