org.jsmpp.util.SequentialBytesReader Maven / Gradle / Ivy
/*
* 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.jsmpp.util;
/**
* Utility to read value from bytes sequentially.
*
* @author uudashr
*
*/
class SequentialBytesReader {
private byte[] bytes;
int cursor;
public SequentialBytesReader(byte[] bytes) {
this.bytes = bytes;
cursor = 0;
}
public byte readByte() {
return bytes[cursor++];
}
public int readInt() {
int val = OctetUtil.bytesToInt(bytes, cursor);
cursor += 4;
return val;
}
public byte[] readBytesUntilNull() {
// TODO uudashr: we can do some improvement here
int i = cursor;
while (bytes[i++] != (byte)0) {
}
int length = i - 1 - cursor;
if (length == 0) {
cursor += 1 + length;
return new byte[] {};
}
byte[] data = new byte[length];
System.arraycopy(bytes, cursor, data, 0, length);
cursor += 1 + length;
return data;
}
/**
* @return String value. Nullable.
*/
public String readCString() {
// TODO uudashr: we can do some improvement here
int i = cursor;
while (bytes[i++] != (byte)0) {
}
int length = i - 1 - cursor;
if (length == 0) {
cursor += 1 + length;
return null;
}
String val = new String(bytes, cursor, length);
cursor += 1 + length;
return val;
}
public byte[] readBytes(int length) {
if (length == 0)
return new byte[0];
byte[] data = new byte[length];
System.arraycopy(bytes, cursor, data, 0, length);
cursor += length;
return data;
}
public byte[] readBytes(byte length) {
return readBytes(length & 0xff);
}
/**
* @param length
* @return String value. Nullable.
*/
public String readString(int length) {
if (length == 0)
return null;
String val = new String(bytes, cursor, length);
cursor += length;
return val;
}
public short readShort() {
short value = OctetUtil.bytesToShort(bytes, cursor);
cursor += 2;
return value;
}
/**
* @param length
* @return String value. Nullable.
*/
public String readString(byte length) {
/*
* you have to convert the signed byte into unsigned byte (in
* integer representation) with & operand by 0xff
*/
return readString(length & 0xff);
}
public int remainBytesLength() {
return bytes.length - cursor;
}
public boolean hasMoreBytes() {
return cursor < (bytes.length - 1);
}
public void resetCursor() {
cursor = 0;
}
public byte[] getBytes() {
return bytes;
}
}
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