/* * Copyright 1999-2011 Alibaba Group. * * 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 com.alibaba.dubbo.common.io; import java.io.IOException; import java.io.Reader; /** * Thread unsafed StringReader. * * @author qian.lei */ public class UnsafeStringReader extends Reader { private String mString; private int mPosition, mLimit, mMark; public UnsafeStringReader(String str) { mString = str; mLimit = str.length(); mPosition = mMark = 0; } @Override public int read() throws IOException { ensureOpen(); if( mPosition >= mLimit ) return -1; return mString.charAt(mPosition++); } @Override public int read(char[] cs, int off, int len) throws IOException { ensureOpen(); if( (off < 0) || (off > cs.length) || (len < 0) || ((off + len) > cs.length) || ((off + len) < 0) ) throw new IndexOutOfBoundsException(); if( len == 0 ) return 0; if( mPosition >= mLimit ) return -1; int n = Math.min(mLimit - mPosition, len); mString.getChars(mPosition, mPosition + n, cs, off); mPosition += n; return n; } public long skip(long ns) throws IOException { ensureOpen(); if( mPosition >= mLimit ) return 0; long n = Math.min(mLimit - mPosition, ns); n = Math.max(-mPosition, n); mPosition += n; return n; } public boolean ready() throws IOException { ensureOpen(); return true; } @Override public boolean markSupported() { return true; } public void mark(int readAheadLimit) throws IOException { if( readAheadLimit < 0 ) throw new IllegalArgumentException("Read-ahead limit < 0"); ensureOpen(); mMark = mPosition; } public void reset() throws IOException { ensureOpen(); mPosition = mMark; } @Override public void close() throws IOException { mString = null; } private void ensureOpen() throws IOException { if( mString == null ) throw new IOException("Stream closed"); } }