/*
* © Copyright IBM Corp. 2012-2013
*
* 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.ibm.commons.util.io;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import com.ibm.commons.util.FastStringBuffer;
/**
* Utilities for working with streams
* @ibm-api
*/
public class StreamUtil {
/**
* Call close on an output stream and ignore any exception.
* @param s the stream to call .close() on
* @return OuputStream null
* @ibm-api
*/
public static OutputStream close(OutputStream s) {
if (s!=null) {
try {
s.close();
}
catch (IOException ioe) {
/** ignore */
}
}
return null;
}
/**
* Call close on an input stream and ignore any exception.
* @param s the stream to call .close() on
* @return InputStream null
* @ibm-api
*/
public static InputStream close(InputStream s) {
if (s!=null) {
try {
s.close();
}
catch (IOException ioe) {
/** ignore */
}
}
return null;
}
/**
* Call close on a Writer and ignore any exception.
* @param s the Writer to call .close() on
* @return Writer null
* @ibm-api
*/
public static Writer close(Writer w) {
if (w!=null) {
try {
w.close();
}
catch (IOException ioe) {
/** ignore */
}
}
return null;
}
/**
* Call close on a Reader and ignore any exception.
* @param s the Reader to call .close() on
* @return Reader null
* @ibm-api
*/
public static Reader close(Reader r) {
if (r!=null) {
try {
r.close();
}
catch (IOException ioe) {
/** ignore */
}
}
return null;
}
/**
* Copy contents of one stream onto another
* @param is input stream
* @param os output stream
* @ibm-api
*/
public static long copyStream(InputStream is, OutputStream os) throws IOException {
return copyStream(is, os, 8192);
}
/**
* Copy contents of one stream onto another
* @param is input stream
* @param os output stream
* @param bufferSize size of buffer to use for copy
*
* Note: there are cases where InputStream.available() returns > 0 but in
* actual fact the stream won't be able to read anything, so we need to
* handle the fact that InputStream.read() may return -1
* @ibm-api
*/
public static long copyStream(InputStream is, OutputStream os, int bufferSize) throws IOException {
byte[] buffer = new byte[bufferSize];
long totalBytes = 0;
int readBytes;
while( (readBytes = is.read(buffer))>0 ) {
os.write(buffer, 0, readBytes);
totalBytes += readBytes;
}
return totalBytes;
}
/**
* Copy contents of one stream onto another
* @param is input stream
* @param os output stream
* @ibm-api
*/
public static long copyStream(Reader is, Writer os) throws IOException {
return copyStream(is, os, 8192);
}
/**
* Copy contents of one character stream onto another
* @param is input stream
* @param os output stream
* @param bufferSize size of buffer to use for copy
*
* Note: there are cases where InputStream.available() returns > 0 but in
* actual fact the stream won't be able to read anything, so we need to
* handle the fact that InputStream.read() may return -1
* @ibm-api
*/
public static long copyStream(Reader is, Writer os, int bufferSize) throws IOException {
char[] buffer = new char[bufferSize];
long totalBytes = 0;
int readBytes;
while( (readBytes = is.read(buffer))>0 ) {
os.write(buffer, 0, readBytes);
totalBytes += readBytes;
}
return totalBytes;
}
/**
* Read a UTF string as written by writeUTF.
* This handles the null strings
* @ibm-api
*/
public static String readUTF(ObjectInput in) throws IOException {
boolean isnull = in.readBoolean();
return isnull ? null : in.readUTF();
}
/**
* Writes a UTF string to be read by readUTF().
* This handles the null strings
* @ibm-api
*/
public static void writeUTF(ObjectOutput out, String s) throws IOException {
if(s==null) {
out.writeBoolean(true);
} else {
out.writeBoolean(false);
out.writeUTF(s);
}
}
/**
* Read a string from a reader.
* @ibm-api
*/
public static String readString(Reader reader) throws IOException {
FastStringBuffer sb = new FastStringBuffer();
sb.load(reader);
return sb.toString();
}
/**
* Read a string from an input stream using the default encoding.
* @ibm-api
*/
public static String readString(InputStream is) throws IOException {
FastStringBuffer sb = new FastStringBuffer();
sb.load(new InputStreamReader(is));
return sb.toString();
}
/**
* Read a string from an input stream using a specific encoding.
* @ibm-api
*/
public static String readString(InputStream is, String encoding) throws IOException {
FastStringBuffer sb = new FastStringBuffer();
sb.load(new InputStreamReader(is,encoding));
return sb.toString();
}
/**
* Fill a buffer as much as we can from InputStream.
* @ibm-api
*/
public static int fillBuffer(byte[] buffer, InputStream is) throws IOException {
int pos=0; int r;
do {
r = is.read(buffer,pos,buffer.length-pos);
if(r>0) { pos+=r; }
} while(r>0 && r<buffer.length);
return pos;
}
}