org.apache.juneau.internal.CharSequenceReader Maven / Gradle / Ivy
// ***************************************************************************************************************************
// * 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.juneau.internal;
import java.io.*;
/**
* Similar to {@link StringReader} except reads from a generic {@link CharSequenceReader}.
*/
public final class CharSequenceReader extends BufferedReader {
private final CharSequence cs;
private String s;
private StringBuffer sb;
private StringBuilder sb2;
private int length;
private int next = 0;
/**
* Constructor.
*
* @param cs The char sequence to read from. Can be null .
*/
public CharSequenceReader(CharSequence cs) {
super(new StringReader(""), 1); // Does not actually use a reader.
if (cs == null)
cs = "";
this.cs = cs;
if (cs instanceof String)
s = (String)cs;
else if (cs instanceof StringBuffer)
sb = (StringBuffer)cs;
else if (cs instanceof StringBuilder)
sb2 = (StringBuilder)cs;
this.length = cs.length();
}
@Override /* Reader */
public int read() {
if (next >= length)
return -1;
return cs.charAt(next++);
}
@Override /* Reader */
public boolean markSupported() {
return false;
}
@Override /* Reader */
public int read(final char[] cbuf, final int off, final int len) {
if (next >= length)
return -1;
int n = Math.min(length - next, len);
if (s != null)
s.getChars(next, next + n, cbuf, off);
else if (sb != null)
sb.getChars(next, next + n, cbuf, off);
else if (sb2 != null)
sb2.getChars(next, next + n, cbuf, off);
else {
for (int i = 0; i < n; i++)
cbuf[off+i] = cs.charAt(next+i);
}
next += n;
return n;
}
@Override /* Reader */
public long skip(long ns) {
if (next >= length)
return 0;
long n = Math.min(length - next, ns);
n = Math.max(-next, n);
next += n;
return n;
}
@Override /* Reader */
public void close() {
// no-op
}
@Override /* Object */
public String toString() {
return cs.toString();
}
}