Fix signed byte to int conversion in ByteBuffer wrappers. Refactor

DoubleBuffer

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TByteBuffer.java

@@ -199,6 +199,14 @@ public abstract class TByteBuffer extends TBuffer implements TComparable<TByteBu
         return this;
     }
 
+    public abstract char getChar();
+
+    public abstract TByteBuffer putChar(char value);
+
+    public abstract char getChar(int index);
+
+    public abstract TByteBuffer putChar(int index, char value);
+
     public abstract TCharBuffer asCharBuffer();
 
     public abstract TShortBuffer asShortBuffer();
@@ -208,4 +216,6 @@ public abstract class TByteBuffer extends TBuffer implements TComparable<TByteBu
     public abstract TLongBuffer asLongBuffer();
 
     public abstract TFloatBuffer asFloatBuffer();
+
+    public abstract TDoubleBuffer asDoubleBuffer();
 }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TByteBufferImpl.java

@@ -103,6 +103,71 @@ class TByteBufferImpl extends TByteBuffer {
         return readOnly;
     }
 
+    @Override
+    public char getChar() {
+        if (position + 1 >= limit) {
+            throw new TBufferUnderflowException();
+        }
+        int a = array[start + position] & 0xFF;
+        int b = array[start + position + 1] & 0xFF;
+        position += 2;
+        if (order == TByteOrder.BIG_ENDIAN) {
+            return (char)(a << 8 | b);
+        } else {
+            return (char)(b << 8 | a);
+        }
+    }
+
+    @Override
+    public TByteBuffer putChar(char value) {
+        if (readOnly) {
+            throw new TReadOnlyBufferException();
+        }
+        if (position + 1 >= limit) {
+            throw new TBufferOverflowException();
+        }
+        if (order == TByteOrder.BIG_ENDIAN) {
+            array[start + position++] = (byte)(value >> 8);
+            array[start + position++] = (byte)value;
+        } else {
+            array[start + position++] = (byte)value;
+            array[start + position++] = (byte)(value >> 8);
+        }
+        return this;
+    }
+
+    @Override
+    public char getChar(int index) {
+        if (index < 0 || index + 1 >= limit) {
+            throw new IndexOutOfBoundsException("Index " + index + " is outside of range [0;" + (limit - 1) + ")");
+        }
+        int a = array[start + index] & 0xFF;
+        int b = array[start + index + 1] & 0xFF;
+        if (order == TByteOrder.BIG_ENDIAN) {
+            return (char)(a << 8 | b);
+        } else {
+            return (char)(b << 8 | a);
+        }
+    }
+
+    @Override
+    public TByteBuffer putChar(int index, char value) {
+        if (readOnly) {
+            throw new TReadOnlyBufferException();
+        }
+        if (index < 0 || index + 1 >= limit) {
+            throw new IndexOutOfBoundsException("Index " + index + " is outside of range [0;" + (limit - 1) + ")");
+        }
+        if (order == TByteOrder.BIG_ENDIAN) {
+            array[start + index] = (byte)(value >> 8);
+            array[start + index + 1] = (byte)value;
+        } else {
+            array[start + index] = (byte)value;
+            array[start + index + 1] = (byte)(value >> 8);
+        }
+        return this;
+    }
+
     @Override
     public TCharBuffer asCharBuffer() {
         int sz = remaining() / 2;
@@ -147,4 +212,13 @@ class TByteBufferImpl extends TByteBuffer {
         result.byteOrder = order;
         return result;
     }
+
+    @Override
+    public TDoubleBuffer asDoubleBuffer() {
+        int sz = remaining() / 8;
+        TDoubleBufferOverByteBuffer result = new TDoubleBufferOverByteBuffer(start + position, sz, this, 0, sz,
+                isReadOnly());
+        result.byteOrder = order;
+        return result;
+    }
 }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TCharBufferOverByteBuffer.java

@@ -45,9 +45,11 @@ class TCharBufferOverByteBuffer extends TCharBufferImpl {
     char getChar(int index) {
         int value;
         if (byteOrder == TByteOrder.BIG_ENDIAN) {
-            value = (byteByffer.array[start + index * 2] << 8) | (byteByffer.array[start + index * 2 + 1]);
+            value = ((byteByffer.array[start + index * 2] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 2 + 1] & 0xFF);
         } else {
-            value = (byteByffer.array[start + index * 2 + 1] << 8) | (byteByffer.array[start + index * 2]);
+            value = ((byteByffer.array[start + index * 2 + 1] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 2] & 0xFF);
         }
         return (char)value;
     }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TDoubleBuffer.java

@@ -20,13 +20,8 @@ package org.teavm.classlib.java.nio;
  * @author Alexey Andreev <konsoletyper@gmail.com>
  */
 public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubleBuffer> {
-    int start;
-    double[] array;
-
-    TDoubleBuffer(int start, int capacity, double[] array, int position, int limit) {
+    TDoubleBuffer(int capacity, int position, int limit) {
         super(capacity);
-        this.start = start;
-        this.array = array;
         this.position = position;
         this.limit = limit;
     }
@@ -35,11 +30,11 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
         if (capacity < 0) {
             throw new IllegalArgumentException("Capacity is negative: " + capacity);
         }
-        return new TDoubleBufferImpl(capacity);
+        return new TDoubleBufferOverArray(capacity);
     }
 
     public static TDoubleBuffer wrap(double[] array, int offset, int length) {
-        return new TDoubleBufferImpl(0, array.length, array, offset, offset + length, false);
+        return new TDoubleBufferOverArray(0, array.length, array, offset, offset + length, false);
     }
 
     public static TDoubleBuffer wrap(double[] array) {
@@ -60,6 +55,10 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
 
     public abstract TDoubleBuffer put(int index, double b);
 
+    abstract double getElement(int index);
+
+    abstract void putElement(int index, double value);
+
     public TDoubleBuffer get(double[] dst, int offset, int length) {
         if (offset < 0 || offset >= dst.length) {
             throw new IndexOutOfBoundsException("Offset " + offset + " is outside of range [0;" + dst.length + ")");
@@ -74,9 +73,9 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
         if (length < 0) {
             throw new IndexOutOfBoundsException("Length " + length + " must be non-negative");
         }
-        int pos = position + start;
+        int pos = position;
         for (int i = 0; i < length; ++i) {
-            dst[offset++] = array[pos++];
+            dst[offset++] = getElement(pos++);
         }
         position += length;
         return this;
@@ -87,7 +86,20 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
     }
 
     public TDoubleBuffer put(TDoubleBuffer src) {
-        return put(src.array, src.start + src.position, src.remaining());
+        if (isReadOnly()) {
+            throw new TReadOnlyBufferException();
+        }
+        if (remaining() < src.remaining()) {
+            throw new TBufferOverflowException();
+        }
+        int length = src.remaining();
+        int pos = position;
+        int offset = src.position;
+        for (int i = 0; i < length; ++i) {
+            putElement(pos++, src.getElement(offset++));
+        }
+        position += length;
+        return this;
     }
 
     public TDoubleBuffer put(double[] src, int offset, int length) {
@@ -107,9 +119,9 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
         if (length < 0) {
             throw new IndexOutOfBoundsException("Length " + length + " must be non-negative");
         }
-        int pos = position + start;
+        int pos = position;
         for (int i = 0; i < length; ++i) {
-            array[pos++] = src[offset++];
+            putElement(pos++, src[offset++]);
         }
         position += length;
         return this;
@@ -120,20 +132,26 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
     }
 
     @Override
-    public boolean hasArray() {
-        return true;
+    public final boolean hasArray() {
+        return isArrayPresent();
     }
 
     @Override
     public final double[] array() {
-        return array;
+        return getArray();
     }
 
     @Override
-    public int arrayOffset() {
-        return start;
+    public final int arrayOffset() {
+        return getArrayOffset();
     }
 
+    abstract boolean isArrayPresent();
+
+    abstract double[] getArray();
+
+    abstract int getArrayOffset();
+
     public abstract TDoubleBuffer compact();
 
     @Override
@@ -148,10 +166,10 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
     @Override
     public int hashCode() {
         int hashCode = 0;
-        int pos = position + start;
+        int pos = position;
         for (int i = position; i < limit; ++i) {
-            long e = Double.doubleToLongBits(array[pos++]);
-            hashCode = 31 * hashCode + (int)e + (int)(e >>> 32);
+            long elem = Double.doubleToLongBits(getElement(pos++));
+            hashCode = 31 * hashCode + (int)elem + (int)(elem >>> 32);
         }
         return hashCode;
     }
@@ -169,10 +187,10 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
         if (sz != other.remaining()) {
             return false;
         }
-        int a = position + start;
-        int b = other.position + other.start;
+        int a = position;
+        int b = other.position;
         for (int i = 0; i < sz; ++i) {
-            if (array[a++] != other.array[b++]) {
+            if (getElement(a++) != other.getElement(b++)) {
                 return false;
             }
         }
@@ -185,14 +203,16 @@ public abstract class TDoubleBuffer extends TBuffer implements Comparable<TDoubl
             return 0;
         }
         int sz = Math.min(remaining(), other.remaining());
-        int a = position + start;
-        int b = other.position + other.start;
+        int a = position;
+        int b = other.position;
         for (int i = 0; i < sz; ++i) {
-            int r = Double.compare(array[a++], other.array[b++]);
+            int r = Double.compare(getElement(a++), other.getElement(b++));
             if (r != 0) {
                 return r;
             }
         }
         return Integer.compare(remaining(), other.remaining());
     }
+
+    public abstract TByteOrder order();
 }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TDoubleBufferImpl.java

@@ -19,50 +19,45 @@ package org.teavm.classlib.java.nio;
  *
  * @author Alexey Andreev <konsoletyper@gmail.com>
  */
-class TDoubleBufferImpl extends TDoubleBuffer {
-    private boolean readOnly;
-
-    public TDoubleBufferImpl(int capacity) {
-        this(0, capacity, new double[capacity], 0, capacity, false);
-    }
-
-    public TDoubleBufferImpl(int start, int capacity, double[] array, int position, int limit, boolean readOnly) {
-        super(start, capacity, array, position, limit);
-        this.readOnly = readOnly;
+abstract class TDoubleBufferImpl extends TDoubleBuffer {
+    public TDoubleBufferImpl(int capacity, int position, int limit) {
+        super(capacity, position, limit);
     }
 
     @Override
     public TDoubleBuffer slice() {
-        return new TDoubleBufferImpl(position, limit - position,  array, 0, limit - position, readOnly);
+        return duplicate(position, limit - position, 0, limit - position, isReadOnly());
     }
 
     @Override
     public TDoubleBuffer duplicate() {
-        return new TDoubleBufferImpl(start, capacity, array, position, limit, readOnly);
+        return duplicate(0, capacity, position, limit, isReadOnly());
     }
 
     @Override
     public TDoubleBuffer asReadOnlyBuffer() {
-        return new TDoubleBufferImpl(start, capacity, array, position, limit, true);
+        return duplicate(0, capacity, position, limit, true);
     }
 
+    abstract TDoubleBuffer duplicate(int start, int capacity, int position, int limit, boolean readOnly);
+
     @Override
     public double get() {
         if (position >= limit) {
             throw new TBufferUnderflowException();
         }
-        return array[start + position++];
+        return getElement(position++);
     }
 
     @Override
     public TDoubleBuffer put(double b) {
-        if (readOnly) {
+        if (isReadOnly()) {
             throw new TReadOnlyBufferException();
         }
         if (position >= limit) {
             throw new TBufferOverflowException();
         }
-        array[start + position++] = b;
+        putElement(position++, b);
         return this;
     }
 
@@ -71,32 +66,31 @@ class TDoubleBufferImpl extends TDoubleBuffer {
         if (index < 0 || index >= limit) {
             throw new IndexOutOfBoundsException("Index " + index + " is outside of range [0;" + limit + ")");
         }
-        return array[start + index];
+        return getElement(index);
     }
 
     @Override
     public TDoubleBuffer put(int index, double b) {
-        if (readOnly) {
+        if (isReadOnly()) {
             throw new TReadOnlyBufferException();
         }
         if (index < 0 || index >= limit) {
             throw new IndexOutOfBoundsException("Index " + index + " is outside of range [0;" + limit + ")");
         }
-        array[start + index] = b;
+        putElement(index, b);
         return this;
     }
 
     @Override
     public TDoubleBuffer compact() {
-        if (readOnly) {
+        if (isReadOnly()) {
             throw new TReadOnlyBufferException();
         }
         if (position > 0) {
             int sz = remaining();
-            int dst = start;
-            int src = start + position;
+            int src = position;
             for (int i = 0; i < sz; ++i) {
-                array[dst++] = array[src++];
+                putElement(i, getElement(src++));
             }
             position = sz;
         }
@@ -112,6 +106,8 @@ class TDoubleBufferImpl extends TDoubleBuffer {
 
     @Override
     public boolean isReadOnly() {
-        return readOnly;
+        return readOnly();
     }
+
+    abstract boolean readOnly();
 }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TDoubleBufferOverArray.java

@@ -0,0 +1,77 @@
+/*
+ *  Copyright 2014 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.nio;
+
+/**
+ *
+ * @author Alexey Andreev <konsoletyper@gmail.com>
+ */
+class TDoubleBufferOverArray extends TDoubleBufferImpl {
+    boolean readOnly;
+    int start;
+    double[] array;
+
+    public TDoubleBufferOverArray(int capacity) {
+        this(0, capacity, new double[capacity], 0, capacity, false);
+    }
+
+    public TDoubleBufferOverArray(int start, int capacity, double[] array, int position, int limit, boolean readOnly) {
+        super(capacity, position, limit);
+        this.start = start;
+        this.readOnly = readOnly;
+        this.array = array;
+    }
+
+    @Override
+    TDoubleBuffer duplicate(int start, int capacity, int position, int limit, boolean readOnly) {
+        return new TDoubleBufferOverArray(this.start + start, capacity, array, position, limit, readOnly);
+    }
+
+    @Override
+    double getElement(int index) {
+        return array[index + start];
+    }
+
+    @Override
+    void putElement(int index, double value) {
+        array[index + start] = value;
+    }
+
+    @Override
+    boolean isArrayPresent() {
+        return true;
+    }
+
+    @Override
+    double[] getArray() {
+        return array;
+    }
+
+    @Override
+    int getArrayOffset() {
+        return start;
+    }
+
+    @Override
+    boolean readOnly() {
+        return readOnly;
+    }
+
+    @Override
+    public TByteOrder order() {
+        return TByteOrder.BIG_ENDIAN;
+    }
+}

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TDoubleBufferOverByteBuffer.java

@@ -0,0 +1,117 @@
+/*
+ *  Copyright 2014 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.nio;
+
+/**
+ *
+ * @author Alexey Andreev <konsoletyper@gmail.com>
+ */
+class TDoubleBufferOverByteBuffer extends TDoubleBufferImpl {
+    private TByteBufferImpl byteByffer;
+    TByteOrder byteOrder = TByteOrder.BIG_ENDIAN;
+    boolean readOnly;
+    private int start;
+
+    public TDoubleBufferOverByteBuffer(int start, int capacity, TByteBufferImpl byteBuffer, int position, int limit,
+            boolean readOnly) {
+        super(capacity, position, limit);
+        this.start = start;
+        this.byteByffer = byteBuffer;
+        this.readOnly = readOnly;
+    }
+
+    @Override
+    TDoubleBuffer duplicate(int start, int capacity, int position, int limit, boolean readOnly) {
+        TDoubleBufferOverByteBuffer result = new TDoubleBufferOverByteBuffer(this.start + start * 2, capacity,
+                byteByffer, position, limit, readOnly);
+        result.byteOrder = byteOrder;
+        return result;
+    }
+
+    @Override
+    double getElement(int index) {
+        long value;
+        if (byteOrder == TByteOrder.BIG_ENDIAN) {
+            value = (((long)byteByffer.array[start + index * 8] & 0xFF) << 56) |
+                    (((long)byteByffer.array[start + index * 8 + 1] & 0xFF) << 48) |
+                    (((long)byteByffer.array[start + index * 8 + 2] & 0xFF) << 40) |
+                    (((long)byteByffer.array[start + index * 8 + 3] & 0xFF) << 32) |
+                    (((long)byteByffer.array[start + index * 8 + 4] & 0xFF) << 24) |
+                    (((long)byteByffer.array[start + index * 8 + 5] & 0xFF) << 16) |
+                    (((long)byteByffer.array[start + index * 8 + 6] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 8 + 7] & 0xFF);
+        } else {
+            value = (byteByffer.array[start + index * 8] & 0xFF) |
+                    (((long)byteByffer.array[start + index * 8 + 1] & 0xFF) << 8) |
+                    (((long)byteByffer.array[start + index * 8 + 2] & 0xFF) << 16) |
+                    (((long)byteByffer.array[start + index * 8 + 3] & 0xFF) << 24) |
+                    (((long)byteByffer.array[start + index * 8 + 4] & 0xFF) << 32) |
+                    (((long)byteByffer.array[start + index * 8 + 5] & 0xFF) << 40) |
+                    (((long)byteByffer.array[start + index * 8 + 6] & 0xFF) << 48) |
+                    (((long)byteByffer.array[start + index * 8 + 7] & 0xFF) << 56);
+        }
+        return Double.longBitsToDouble(value);
+    }
+
+    @Override
+    void putElement(int index, double d) {
+        long value = Double.doubleToLongBits(d);
+        if (byteOrder == TByteOrder.BIG_ENDIAN) {
+            byteByffer.array[start + index * 8] = (byte)(value >> 56);
+            byteByffer.array[start + index * 8 + 1] = (byte)(value >> 48);
+            byteByffer.array[start + index * 8 + 2] = (byte)(value >> 40);
+            byteByffer.array[start + index * 8 + 3] = (byte)(value >> 32);
+            byteByffer.array[start + index * 8 + 4] = (byte)(value >> 24);
+            byteByffer.array[start + index * 8 + 5] = (byte)(value >> 16);
+            byteByffer.array[start + index * 8 + 6] = (byte)(value >> 8);
+            byteByffer.array[start + index * 8 + 7] = (byte)value;
+        } else {
+            byteByffer.array[start + index * 8] = (byte)value;
+            byteByffer.array[start + index * 8 + 1] = (byte)(value >> 8);
+            byteByffer.array[start + index * 8 + 2] = (byte)(value >> 16);
+            byteByffer.array[start + index * 8 + 3] = (byte)(value >> 24);
+            byteByffer.array[start + index * 8 + 4] = (byte)(value >> 32);
+            byteByffer.array[start + index * 8 + 5] = (byte)(value >> 40);
+            byteByffer.array[start + index * 8 + 6] = (byte)(value >> 48);
+            byteByffer.array[start + index * 8 + 7] = (byte)(value >> 56);
+        }
+    }
+
+    @Override
+    boolean isArrayPresent() {
+        return false;
+    }
+
+    @Override
+    double[] getArray() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    int getArrayOffset() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    boolean readOnly() {
+        return readOnly;
+    }
+
+    @Override
+    public TByteOrder order() {
+        return byteOrder;
+    }
+}

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TFloatBufferOverByteBuffer.java

@@ -45,15 +45,15 @@ class TFloatBufferOverByteBuffer extends TFloatBufferImpl {
     float getElement(int index) {
         int value;
         if (byteOrder == TByteOrder.BIG_ENDIAN) {
-            value = (byteByffer.array[start + index * 4] << 24) |
-                    (byteByffer.array[start + index * 4 + 1] << 16) |
-                    (byteByffer.array[start + index * 4 + 2] << 8) |
-                    (byteByffer.array[start + index * 4 + 3]);
+            value = ((byteByffer.array[start + index * 4] & 0xFF) << 24) |
+                    ((byteByffer.array[start + index * 4 + 1] & 0xFF) << 16) |
+                    ((byteByffer.array[start + index * 4 + 2] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 4 + 3] & 0xFF);
         } else {
-            value = (byteByffer.array[start + index * 4]) |
-                    (byteByffer.array[start + index * 4 + 1] << 8) |
-                    (byteByffer.array[start + index * 4 + 2] << 16) |
-                    (byteByffer.array[start + index * 4 + 3] << 24);
+            value = (byteByffer.array[start + index * 4] & 0xFF) |
+                    ((byteByffer.array[start + index * 4 + 1] & 0xFF) << 8) |
+                    ((byteByffer.array[start + index * 4 + 2] & 0xFF) << 16) |
+                    ((byteByffer.array[start + index * 4 + 3] & 0xFF) << 24);
         }
         return Float.intBitsToFloat(value);
     }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TIntBufferOverByteBuffer.java

@@ -45,15 +45,15 @@ public class TIntBufferOverByteBuffer extends TIntBufferImpl {
     int getElement(int index) {
         int value;
         if (byteOrder == TByteOrder.BIG_ENDIAN) {
-            value = (byteByffer.array[start + index * 4] << 24) |
-                    (byteByffer.array[start + index * 4 + 1] << 16) |
-                    (byteByffer.array[start + index * 4 + 2] << 8) |
-                    (byteByffer.array[start + index * 4 + 3]);
+            value = ((byteByffer.array[start + index * 4] & 0xFF) << 24) |
+                    ((byteByffer.array[start + index * 4 + 1] & 0xFF) << 16) |
+                    ((byteByffer.array[start + index * 4 + 2] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 4 + 3] & 0xFF);
         } else {
-            value = (byteByffer.array[start + index * 4]) |
-                    (byteByffer.array[start + index * 4 + 1] << 8) |
-                    (byteByffer.array[start + index * 4 + 2] << 16) |
-                    (byteByffer.array[start + index * 4 + 3] << 24);
+            value = (byteByffer.array[start + index * 4] & 0xFF) |
+                    ((byteByffer.array[start + index * 4 + 1] & 0xFF) << 8) |
+                    ((byteByffer.array[start + index * 4 + 2] & 0xFF) << 16) |
+                    ((byteByffer.array[start + index * 4 + 3] & 0xFF) << 24);
         }
         return value;
     }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TLongBufferOverByteBuffer.java

@@ -45,23 +45,23 @@ class TLongBufferOverByteBuffer extends TLongBufferImpl {
     long getElement(int index) {
         long value;
         if (byteOrder == TByteOrder.BIG_ENDIAN) {
-            value = ((long)byteByffer.array[start + index * 8] << 56) |
-                    ((long)byteByffer.array[start + index * 8 + 1] << 48) |
-                    ((long)byteByffer.array[start + index * 8 + 2] << 40) |
-                    ((long)byteByffer.array[start + index * 8 + 3] << 32) |
-                    ((long)byteByffer.array[start + index * 8 + 4] << 24) |
-                    ((long)byteByffer.array[start + index * 8 + 5] << 16) |
-                    ((long)byteByffer.array[start + index * 8 + 6] << 8) |
-                    byteByffer.array[start + index * 8 + 7];
+            value = (((long)byteByffer.array[start + index * 8] & 0xFF) << 56) |
+                    (((long)byteByffer.array[start + index * 8 + 1] & 0xFF) << 48) |
+                    (((long)byteByffer.array[start + index * 8 + 2] & 0xFF) << 40) |
+                    (((long)byteByffer.array[start + index * 8 + 3] & 0xFF) << 32) |
+                    (((long)byteByffer.array[start + index * 8 + 4] & 0xFF) << 24) |
+                    (((long)byteByffer.array[start + index * 8 + 5] & 0xFF) << 16) |
+                    (((long)byteByffer.array[start + index * 8 + 6] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 8 + 7] & 0xFF);
         } else {
-            value = byteByffer.array[start + index * 8] |
-                    ((long)byteByffer.array[start + index * 8 + 1] << 8) |
-                    ((long)byteByffer.array[start + index * 8 + 2] << 16) |
-                    ((long)byteByffer.array[start + index * 8 + 3] << 24) |
-                    ((long)byteByffer.array[start + index * 8 + 4] << 32) |
-                    ((long)byteByffer.array[start + index * 8 + 5] << 40) |
-                    ((long)byteByffer.array[start + index * 8 + 6] << 48) |
-                    ((long)byteByffer.array[start + index * 8 + 7] << 56);
+            value = (byteByffer.array[start + index * 8] & 0xFF) |
+                    (((long)byteByffer.array[start + index * 8 + 1] & 0xFF) << 8) |
+                    (((long)byteByffer.array[start + index * 8 + 2] & 0xFF) << 16) |
+                    (((long)byteByffer.array[start + index * 8 + 3] & 0xFF) << 24) |
+                    (((long)byteByffer.array[start + index * 8 + 4] & 0xFF) << 32) |
+                    (((long)byteByffer.array[start + index * 8 + 5] & 0xFF) << 40) |
+                    (((long)byteByffer.array[start + index * 8 + 6] & 0xFF) << 48) |
+                    (((long)byteByffer.array[start + index * 8 + 7] & 0xFF) << 56);
         }
         return value;
     }

teavm-classlib/src/main/java/org/teavm/classlib/java/nio/TShortBufferOverByteBuffer.java

@@ -45,9 +45,11 @@ class TShortBufferOverByteBuffer extends TShortBufferImpl {
     short getElement(int index) {
         int value;
         if (byteOrder == TByteOrder.BIG_ENDIAN) {
-            value = (byteByffer.array[start + index * 2] << 8) | (byteByffer.array[start + index * 2 + 1]);
+            value = ((byteByffer.array[start + index * 2] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 2 + 1] & 0xFF);
         } else {
-            value = (byteByffer.array[start + index * 2 + 1] << 8) | (byteByffer.array[start + index * 2]);
+            value = ((byteByffer.array[start + index * 2 + 1] & 0xFF) << 8) |
+                    (byteByffer.array[start + index * 2] & 0xFF);
         }
         return (short)value;
     }