quick sketch of java/io/*

classpath/java/io/InputStream.java

@@ -0,0 +1,27 @@
+package java.io;
+
+public abstract class InputStream {
+  public abstract int read() throws IOException;
+
+  public int read(byte[] buffer) throws IOException {
+    return read(buffer, 0, buffer.length);
+  }
+
+  public int read(byte[] buffer, int offset, int length) throws IOException {
+    for (int i = 0; i < length; ++i) {
+      int c = read();
+      if (c == -1) {
+        if (i == 0) {
+          return -1;
+        } else {
+          return i;
+        }
+      } else {
+        buffer[offset + i] = (byte) (c & 0xFF);
+      }
+    }
+    return length;
+  }
+
+  public void close() throws IOException { }
+}