summaryrefslogtreecommitdiffstats
path: root/src/org/apache/commons/io/input/CharSequenceReader.java
diff options
context:
space:
mode:
Diffstat (limited to 'src/org/apache/commons/io/input/CharSequenceReader.java')
-rw-r--r--src/org/apache/commons/io/input/CharSequenceReader.java155
1 files changed, 155 insertions, 0 deletions
diff --git a/src/org/apache/commons/io/input/CharSequenceReader.java b/src/org/apache/commons/io/input/CharSequenceReader.java
new file mode 100644
index 000000000..6ee11d87d
--- /dev/null
+++ b/src/org/apache/commons/io/input/CharSequenceReader.java
@@ -0,0 +1,155 @@
+/*
+ * 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.commons.io.input;
+
+import java.io.Reader;
+import java.io.Serializable;
+
+/**
+ * {@link Reader} implementation that can read from String, StringBuffer,
+ * StringBuilder or CharBuffer.
+ * <p>
+ * <strong>Note:</strong> Supports {@link #mark(int)} and {@link #reset()}.
+ *
+ * @version $Revision: 610516 $ $Date: 2008-01-09 19:05:05 +0000 (Wed, 09 Jan 2008) $
+ * @since Commons IO 1.4
+ */
+public class CharSequenceReader extends Reader implements Serializable {
+
+ private final CharSequence charSequence;
+ private int idx;
+ private int mark;
+
+ /**
+ * Construct a new instance with the specified character sequence.
+ *
+ * @param charSequence The character sequence, may be <code>null</code>
+ */
+ public CharSequenceReader(CharSequence charSequence) {
+ this.charSequence = (charSequence != null ? charSequence : "");
+ }
+
+ /**
+ * Close resets the file back to the start and removes any marked position.
+ */
+ public void close() {
+ idx = 0;
+ mark = 0;
+ }
+
+ /**
+ * Mark the current position.
+ *
+ * @param readAheadLimit ignored
+ */
+ public void mark(int readAheadLimit) {
+ mark = idx;
+ }
+
+ /**
+ * Mark is supported (returns true).
+ *
+ * @return <code>true</code>
+ */
+ public boolean markSupported() {
+ return true;
+ }
+
+ /**
+ * Read a single character.
+ *
+ * @return the next character from the character sequence
+ * or -1 if the end has been reached.
+ */
+ public int read() {
+ if (idx >= charSequence.length()) {
+ return -1;
+ } else {
+ return charSequence.charAt(idx++);
+ }
+ }
+
+ /**
+ * Read the sepcified number of characters into the array.
+ *
+ * @param array The array to store the characters in
+ * @param offset The starting position in the array to store
+ * @param length The maximum number of characters to read
+ * @return The number of characters read or -1 if there are
+ * no more
+ */
+ public int read(char[] array, int offset, int length) {
+ if (idx >= charSequence.length()) {
+ return -1;
+ }
+ if (array == null) {
+ throw new NullPointerException("Character array is missing");
+ }
+ if (length < 0 || (offset + length) > array.length) {
+ throw new IndexOutOfBoundsException("Array Size=" + array.length +
+ ", offset=" + offset + ", length=" + length);
+ }
+ int count = 0;
+ for (int i = 0; i < length; i++) {
+ int c = read();
+ if (c == -1) {
+ return count;
+ }
+ array[offset + i] = (char)c;
+ count++;
+ }
+ return count;
+ }
+
+ /**
+ * Reset the reader to the last marked position (or the beginning if
+ * mark has not been called).
+ */
+ public void reset() {
+ idx = mark;
+ }
+
+ /**
+ * Skip the specified number of characters.
+ *
+ * @param n The number of characters to skip
+ * @return The actual number of characters skipped
+ */
+ public long skip(long n) {
+ if (n < 0) {
+ throw new IllegalArgumentException(
+ "Number of characters to skip is less than zero: " + n);
+ }
+ if (idx >= charSequence.length()) {
+ return -1;
+ }
+ int dest = (int)Math.min(charSequence.length(), (idx + n));
+ int count = dest - idx;
+ idx = dest;
+ return count;
+ }
+
+ /**
+ * Return a String representation of the underlying
+ * character sequence.
+ *
+ * @return The contents of the character sequence
+ */
+ public String toString() {
+ return charSequence.toString();
+ }
+}