Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.thrift; import java.io.Serializable; import java.nio.ByteBuffer; import java.util.Comparator; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import java.util.SortedMap; import java.util.TreeMap; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; public final class TBaseHelper { private TBaseHelper() { } private static final Comparator comparator = new NestedStructureComparator(); public static int compareTo(Object o1, Object o2) { if (o1 instanceof Comparable) { return compareTo((Comparable) o1, (Comparable) o2); } else if (o1 instanceof List) { return compareTo((List) o1, (List) o2); } else if (o1 instanceof Set) { return compareTo((Set) o1, (Set) o2); } else if (o1 instanceof Map) { return compareTo((Map) o1, (Map) o2); } else if (o1 instanceof byte[]) { return compareTo((byte[]) o1, (byte[]) o2); } else { throw new IllegalArgumentException("Cannot compare objects of type " + o1.getClass()); } } public static int compareTo(boolean a, boolean b) { return Boolean.compare(a, b); } public static int compareTo(byte a, byte b) { return Byte.compare(a, b); } public static int compareTo(short a, short b) { return Short.compare(a, b); } public static int compareTo(int a, int b) { return Integer.compare(a, b); } public static int compareTo(long a, long b) { return Long.compare(a, b); } public static int compareTo(double a, double b) { return Double.compare(a, b); } public static int compareTo(String a, String b) { return a.compareTo(b); } public static int compareTo(byte[] a, byte[] b) { int compare = compareTo(a.length, b.length); if (compare == 0) { for (int i = 0; i < a.length; i++) { compare = compareTo(a[i], b[i]); if (compare != 0) { break; } } } return compare; } public static int compareTo(Comparable a, Comparable b) { return a.compareTo(b); } public static int compareTo(List a, List b) { int compare = compareTo(a.size(), b.size()); if (compare == 0) { for (int i = 0; i < a.size(); i++) { compare = comparator.compare(a.get(i), b.get(i)); if (compare != 0) { break; } } } return compare; } public static int compareTo(Set a, Set b) { int compare = compareTo(a.size(), b.size()); if (compare == 0) { ArrayList sortedA = new ArrayList(a); ArrayList sortedB = new ArrayList(b); Collections.sort(sortedA, comparator); Collections.sort(sortedB, comparator); Iterator iterA = sortedA.iterator(); Iterator iterB = sortedB.iterator(); // Compare each item. while (iterA.hasNext() && iterB.hasNext()) { compare = comparator.compare(iterA.next(), iterB.next()); if (compare != 0) { break; } } } return compare; } public static int compareTo(Map a, Map b) { int lastComparison = compareTo(a.size(), b.size()); if (lastComparison != 0) { return lastComparison; } // Sort a and b so we can compare them. SortedMap sortedA = new TreeMap(comparator); sortedA.putAll(a); Iterator<Map.Entry> iterA = sortedA.entrySet().iterator(); SortedMap sortedB = new TreeMap(comparator); sortedB.putAll(b); Iterator<Map.Entry> iterB = sortedB.entrySet().iterator(); // Compare each item. while (iterA.hasNext() && iterB.hasNext()) { Map.Entry entryA = iterA.next(); Map.Entry entryB = iterB.next(); lastComparison = comparator.compare(entryA.getKey(), entryB.getKey()); if (lastComparison != 0) { return lastComparison; } lastComparison = comparator.compare(entryA.getValue(), entryB.getValue()); if (lastComparison != 0) { return lastComparison; } } return 0; } /** * Comparator to compare items inside a structure (e.g. a list, set, or map). */ private static class NestedStructureComparator implements Comparator, Serializable { public int compare(Object oA, Object oB) { if (oA == null && oB == null) { return 0; } else if (oA == null) { return -1; } else if (oB == null) { return 1; } else if (oA instanceof List) { return compareTo((List) oA, (List) oB); } else if (oA instanceof Set) { return compareTo((Set) oA, (Set) oB); } else if (oA instanceof Map) { return compareTo((Map) oA, (Map) oB); } else if (oA instanceof byte[]) { return compareTo((byte[]) oA, (byte[]) oB); } else { return compareTo((Comparable) oA, (Comparable) oB); } } } public static void toString(Collection<ByteBuffer> bbs, StringBuilder sb) { Iterator<ByteBuffer> it = bbs.iterator(); if (!it.hasNext()) { sb.append("[]"); } else { sb.append("["); while (true) { ByteBuffer bb = it.next(); org.apache.thrift.TBaseHelper.toString(bb, sb); if (!it.hasNext()) { sb.append("]"); return; } else { sb.append(", "); } } } } public static void toString(ByteBuffer bb, StringBuilder sb) { byte[] buf = bb.array(); int arrayOffset = bb.arrayOffset(); int offset = arrayOffset + bb.position(); int origLimit = arrayOffset + bb.limit(); int limit = (origLimit - offset > 128) ? offset + 128 : origLimit; for (int i = offset; i < limit; i++) { if (i > offset) { sb.append(" "); } sb.append(paddedByteString(buf[i])); } if (origLimit != limit) { sb.append("..."); } } public static String paddedByteString(byte b) { int extended = (b | 0x100) & 0x1ff; return Integer.toHexString(extended).toUpperCase().substring(1); } public static byte[] byteBufferToByteArray(ByteBuffer byteBuffer) { if (wrapsFullArray(byteBuffer)) { return byteBuffer.array(); } byte[] target = new byte[byteBuffer.remaining()]; byteBufferToByteArray(byteBuffer, target, 0); return target; } public static boolean wrapsFullArray(ByteBuffer byteBuffer) { return byteBuffer.hasArray() && byteBuffer.position() == 0 && byteBuffer.arrayOffset() == 0 && byteBuffer.remaining() == byteBuffer.capacity(); } public static int byteBufferToByteArray(ByteBuffer byteBuffer, byte[] target, int offset) { int remaining = byteBuffer.remaining(); System.arraycopy(byteBuffer.array(), byteBuffer.arrayOffset() + byteBuffer.position(), target, offset, remaining); return remaining; } public static ByteBuffer rightSize(ByteBuffer in) { if (in == null) { return null; } if (wrapsFullArray(in)) { return in; } return ByteBuffer.wrap(byteBufferToByteArray(in)); } public static ByteBuffer copyBinary(final ByteBuffer orig) { if (orig == null) { return null; } ByteBuffer copy = ByteBuffer.wrap(new byte[orig.remaining()]); if (orig.hasArray()) { System.arraycopy(orig.array(), orig.arrayOffset() + orig.position(), copy.array(), 0, orig.remaining()); } else { orig.slice().get(copy.array()); } return copy; } public static byte[] copyBinary(final byte[] orig) { return (orig == null) ? null : Arrays.copyOf(orig, orig.length); } public static int hashCode(long value) { return Long.hashCode(value); } public static int hashCode(double value) { return Double.hashCode(value); } }