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/*
* Copyright 2011 Vaadin Ltd.
*
* 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.vaadin.data.util;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.nio.charset.Charset;
/**
* Property implementation for wrapping a text file.
*
* Supports reading and writing of a File from/to String.
*
* {@link ValueChangeListener}s are supported, but only fire when
* setValue(Object) is explicitly called. {@link ReadOnlyStatusChangeListener}s
* are supported but only fire when setReadOnly(boolean) is explicitly called.
*
*/
@SuppressWarnings("serial")
public class TextFileProperty extends AbstractProperty<String> {
private File file;
private Charset charset = null;
/**
* Wrap given file with property interface.
*
* Setting the file to null works, but getValue() will return null.
*
* @param file
* File to be wrapped.
*/
public TextFileProperty(File file) {
this.file = file;
}
/**
* Wrap the given file with the property interface and specify character
* set.
*
* Setting the file to null works, but getValue() will return null.
*
* @param file
* File to be wrapped.
* @param charset
* Charset to be used for reading and writing the file.
*/
public TextFileProperty(File file, Charset charset) {
this.file = file;
this.charset = charset;
}
/*
* (non-Javadoc)
*
* @see com.vaadin.data.Property#getType()
*/
@Override
public Class<String> getType() {
return String.class;
}
/*
* (non-Javadoc)
*
* @see com.vaadin.data.Property#getValue()
*/
@Override
public String getValue() {
if (file == null) {
return null;
}
try {
FileInputStream fis = new FileInputStream(file);
InputStreamReader isr = charset == null ? new InputStreamReader(fis)
: new InputStreamReader(fis, charset);
BufferedReader r = new BufferedReader(isr);
StringBuilder b = new StringBuilder();
char buf[] = new char[8 * 1024];
int len;
while ((len = r.read(buf)) != -1) {
b.append(buf, 0, len);
}
r.close();
isr.close();
fis.close();
return b.toString();
} catch (FileNotFoundException e) {
return null;
} catch (IOException e) {
throw new RuntimeException(e);
}
}
/*
* (non-Javadoc)
*
* @see com.vaadin.data.Property#isReadOnly()
*/
@Override
public boolean isReadOnly() {
return file == null || super.isReadOnly() || !file.canWrite();
}
/*
* (non-Javadoc)
*
* @see com.vaadin.data.Property#setValue(java.lang.Object)
*/
@Override
public void setValue(String newValue) throws ReadOnlyException {
if (isReadOnly()) {
throw new ReadOnlyException();
}
if (file == null) {
return;
}
try {
FileOutputStream fos = new FileOutputStream(file);
OutputStreamWriter osw = charset == null ? new OutputStreamWriter(
fos) : new OutputStreamWriter(fos, charset);
BufferedWriter w = new BufferedWriter(osw);
w.append(newValue.toString());
w.flush();
w.close();
osw.close();
fos.close();
fireValueChange();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
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