net.sf.rubycollect4j.RubyIO Maven / Gradle / Ivy
/**
*
* @author Wei-Ming Wu
*
*
* Copyright 2013 Wei-Ming Wu
*
* 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 net.sf.rubycollect4j;
import static net.sf.rubycollect4j.RubyCollections.Hash;
import static net.sf.rubycollect4j.RubyCollections.hp;
import static net.sf.rubycollect4j.RubyCollections.newRubyEnumerator;
import static net.sf.rubycollect4j.RubyCollections.ra;
import static net.sf.rubycollect4j.RubyIO.Mode.R;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Map;
import java.util.Map.Entry;
import java.util.logging.Level;
import java.util.logging.Logger;
import net.sf.rubycollect4j.block.Block;
import net.sf.rubycollect4j.block.TransformBlock;
import net.sf.rubycollect4j.iter.EachLineIterable;
/**
*
* RubyIO implements part of the methods refer to the IO class of Ruby.
*
*/
public class RubyIO {
/**
*
* This Mode enum contains all open modes of RubyIO.
* r : Read.
* r+ : Read and Write.
* w : Write.
* w+ : Write and Read.
* a : Append.
* a+ : Append and Read.
*
*/
public enum Mode {
/**
* Read.
*/
R("r", true, false),
/**
* Read and Write.
*/
RW("r+", true, true),
/**
* Write.
*/
W("w", false, true),
/**
* Write and Read.
*/
WR("w+", true, true),
/**
* Append.
*/
A("a", false, true),
/**
* Append and Read.
*/
AR("a+", true, true);
private static final Map modeMap = Hash(
ra(values()).map(new TransformBlock>() {
@Override
public Entry yield(Mode item) {
return hp(item.toString(), item);
}
})).freeze();
private final String mode;
private final boolean isReadable;
private final boolean isWritable;
private Mode(String mode, boolean isReadable, boolean isWritable) {
this.mode = mode;
this.isReadable = isReadable;
this.isWritable = isWritable;
}
/**
* Checks if it is readable.
*
* @return true if it allows to be read, false otherwise
*/
public boolean isReadable() {
return isReadable;
}
/**
* Checks if it is Writable.
*
* @return true if it allows to be written, false otherwise
*/
public boolean isWritable() {
return isWritable;
}
/**
* Retrieves a Mode from a String.
*
* @param mode
* mode in String form
* @return a Mode
* @throws IllegalArgumentException
* if the permission is not matched any of the Mode
*/
public static Mode fromString(String mode) {
if (modeMap.containsKey(mode))
return modeMap.get(mode);
else
throw new IllegalArgumentException(
"ArgumentError: invalid access mode " + mode);
}
@Override
public String toString() {
return mode;
}
}
private static final Logger logger = Logger.getLogger(RubyIO.class.getName());
protected final File file;
protected final RandomAccessFile raFile;
protected final Mode mode;
/**
* Creates a RubyIO by given path and mode.
*
* @param path
* of a File
* @param mode
* r, rw, w, w+, a, a+
* @see Mode
* @return a RubyIO
*/
public static RubyIO open(String path, String mode) {
RubyIO io = null;
try {
io = new RubyIO(new File(path), Mode.fromString(mode));
} catch (IOException e) {
logger.log(Level.SEVERE, null, e);
throw new RuntimeException(e);
}
return io;
}
/**
* Creates a RubyIO by given file. Sets the mode to read-only.
*
* @param path
* of a file
* @return a RubyIO
*/
public static RubyIO open(String path) {
return open(path, R.toString());
}
/**
* Creates an RubyIO by given File and Mode.
*
* @param file
* a File
* @param mode
* a Mode
* @see Mode
* @throws NullPointerException
* if file is null
* @throws IOException
* if file can't not open
*/
public RubyIO(File file, Mode mode) throws IOException {
if (file == null)
throw new NullPointerException();
this.file = file;
switch (mode) {
case RW:
raFile = new RandomAccessFile(file, "rws");
this.mode = mode;
raFile.seek(0);
break;
case W:
raFile = new RandomAccessFile(file, "rws");
this.mode = mode;
raFile.setLength(0);
raFile.seek(0);
break;
case WR:
raFile = new RandomAccessFile(file, "rws");
this.mode = mode;
raFile.setLength(0);
raFile.seek(0);
break;
case A:
raFile = new RandomAccessFile(file, "rws");
this.mode = mode;
raFile.seek(raFile.length());
break;
case AR:
raFile = new RandomAccessFile(file, "rws");
this.mode = mode;
raFile.seek(raFile.length());
break;
default:
raFile = new RandomAccessFile(file, "r");
this.mode = Mode.R;
break;
}
}
/**
* Returns a RubyEnumerator of lines in given file.
*
* @param path
* of a File
* @return a RubyEnumerator
*/
public static RubyEnumerator foreach(String path) {
return newRubyEnumerator(new EachLineIterable(new File(path)));
}
/**
* Iterates a file line by line.
*
* @param path
* of a File
* @param block
* to process each line
*/
public static void foreach(String path, Block block) {
newRubyEnumerator(new EachLineIterable(new File(path))).each(block);
}
/**
* Closes this IO.
*/
public void close() {
try {
raFile.close();
} catch (IOException e) {
logger.log(Level.SEVERE, null, e);
throw new RuntimeException(e);
}
}
/**
* Returns a RubyEnumerator of lines in the file.
*
* @return a RubyEnumerator
* @throws IllegalStateException
* if file is not readable
*/
public RubyEnumerator eachLine() {
if (mode.isReadable() == false)
throw new IllegalStateException("IOError: not opened for reading");
return newRubyEnumerator(new EachLineIterable(file));
}
/**
* Writes a line in the file.
*
* @param words
* to write a line
* @throws IllegalStateException
* if file is not writable
*/
public void puts(String words) {
if (mode.isWritable() == false)
throw new IllegalStateException("IOError: not opened for writing");
try {
raFile.write(words.getBytes());
raFile.writeBytes(System.getProperty("line.separator"));
} catch (IOException e) {
logger.log(Level.SEVERE, null, e);
throw new RuntimeException(e);
}
}
/**
* Reads the content of a file.
*
* @return a String
* @throws IllegalStateException
* if file is not readable
*/
public String read() {
if (mode.isReadable() == false)
throw new IllegalStateException("IOError: not opened for reading");
StringBuilder sb = new StringBuilder();
try {
BufferedReader reader = new BufferedReader(new FileReader(file));
char[] buf = new char[1024];
int numOfChars = 0;
while ((numOfChars = reader.read(buf)) != -1) {
sb.append(String.valueOf(buf, 0, numOfChars));
}
reader.close();
} catch (IOException e) {
logger.log(Level.SEVERE, null, e);
throw new RuntimeException(e);
}
return sb.toString();
}
/**
* Moves the cursor to certain position.
*
* @param pos
* of the file
*/
public void seek(long pos) {
try {
raFile.seek(pos);
} catch (IOException e) {
logger.log(Level.SEVERE, null, e);
throw new RuntimeException(e);
}
}
/**
* Writes to the file.
*
* @param words
* to write
* @return the number of written bytes.
* @throws IllegalStateException
* if file is not writable
*/
public int write(String words) {
if (mode.isWritable() == false)
throw new IllegalStateException("IOError: not opened for writing");
try {
raFile.write(words.getBytes());
} catch (IOException e) {
logger.log(Level.SEVERE, null, e);
throw new RuntimeException(e);
}
return words.getBytes().length;
}
@Override
public String toString() {
return "RubyIO{path=" + file.getPath() + ", mode=" + mode + "}";
}
}
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