/*
* Copyright 2016 the original author or authors.
*
* 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.springframework.batch.item.file.builder;
import org.springframework.batch.item.file.FlatFileFooterCallback;
import org.springframework.batch.item.file.FlatFileHeaderCallback;
import org.springframework.batch.item.file.FlatFileItemWriter;
import org.springframework.batch.item.file.transform.LineAggregator;
import org.springframework.core.io.Resource;
import org.springframework.util.Assert;
/**
* A builder implementation for the {@link FlatFileItemWriter}
*
* @author Michael Minella
* @since 4.0
* @see FlatFileItemWriter
*/
public class FlatFileItemWriterBuilder<T> {
private Resource resource;
private boolean forceSync = false;
private String lineSeparator = FlatFileItemWriter.DEFAULT_LINE_SEPARATOR;
private LineAggregator<T> lineAggregator;
private String encoding = FlatFileItemWriter.DEFAULT_CHARSET;
private boolean shouldDeleteIfExists = true;
private boolean append = false;
private boolean shouldDeleteIfEmpty = false;
private boolean saveState = true;
private FlatFileHeaderCallback headerCallback;
private FlatFileFooterCallback footerCallback;
private boolean transactional = FlatFileItemWriter.DEFAULT_TRANSACTIONAL;
private String name;
/**
* The name used to calculate the key within the
* {@link org.springframework.batch.item.ExecutionContext}. Required if
* {@link FlatFileItemWriterBuilder#saveState(boolean)} is set to true.
*
* @param name name of the writer instance
* @return The current instance of the builder.
* @see FlatFileItemWriter#setName(String)
*/
public FlatFileItemWriterBuilder<T> name(String name) {
this.name = name;
return this;
}
/**
* The {@link Resource} to be used as output.
*
* @param resource the output of the writer.
* @return The current instance of the builder.
* @see FlatFileItemWriter#setResource(Resource)
*/
public FlatFileItemWriterBuilder<T> resource(Resource resource) {
this.resource = resource;
return this;
}
/**
* A flag indicating that changes should be force-synced to disk on flush. Defaults
* to false.
*
* @param forceSync value to set the flag to
* @return The current instance of the builder.
* @see FlatFileItemWriter#setForceSync(boolean)
*/
public FlatFileItemWriterBuilder<T> forceSync(boolean forceSync) {
this.forceSync = forceSync;
return this;
}
/**
* String used to separate lines in output. Defaults to the System property
* line.separator.
*
* @param lineSeparator value to use for a line separator
* @return The current instance of the builder.
* @see FlatFileItemWriter#setLineSeparator(String)
*/
public FlatFileItemWriterBuilder<T> lineSeparator(String lineSeparator) {
this.lineSeparator = lineSeparator;
return this;
}
/**
* Line aggregator used to build the String version of each item.
*
* @param lineAggregator {@link LineAggregator} implementation
* @return The current instance of the builder.
* @see FlatFileItemWriter#setLineAggregator(LineAggregator)
*/
public FlatFileItemWriterBuilder<T> lineAggregator(LineAggregator<T> lineAggregator) {
this.lineAggregator = lineAggregator;
return this;
}
/**
* Encoding used for output.
*
* @param encoding encoding type.
* @return The current instance of the builder.
* @see FlatFileItemWriter#setEncoding(String)
*/
public FlatFileItemWriterBuilder<T> encoding(String encoding) {
this.encoding = encoding;
return this;
}
/**
* If set to true, once the step is complete, if the resource previously provdied is
* empty, it will be deleted.
*
* @param shouldDelete defaults to false
* @return The current instance of the builder
* @see FlatFileItemWriter#setShouldDeleteIfEmpty(boolean)
*/
public FlatFileItemWriterBuilder<T> shouldDeleteIfEmpty(boolean shouldDelete) {
this.shouldDeleteIfEmpty = shouldDelete;
return this;
}
/**
* If set to true, upon the start of the step, if the resource already exists, it will
* be deleted and recreated.
*
* @param shouldDelete defaults to true
* @return The current instance of the builder
* @see FlatFileItemWriter#setShouldDeleteIfExists(boolean)
*/
public FlatFileItemWriterBuilder<T> shouldDeleteIfExists(boolean shouldDelete) {
this.shouldDeleteIfExists = shouldDelete;
return this;
}
/**
* If set to true and the file exists, the output will be appended to the existing
* file.
*
* @param append defaults to false
* @return The current instance of the builder
* @see FlatFileItemWriter#setAppendAllowed(boolean)
*/
public FlatFileItemWriterBuilder<T> append(boolean append) {
this.append = append;
return this;
}
/**
* If set to false, the state of the output is not maintained and restart is not
* supported.
*
* @param saveState defaults to true
* @return The current instance of the builder
* @see FlatFileItemWriter#setSaveState(boolean)
*/
public FlatFileItemWriterBuilder<T> saveState(boolean saveState) {
this.saveState = saveState;
return this;
}
/**
* A callback for header processing.
*
* @param callback {@link FlatFileHeaderCallback} impl
* @return The current instance of the builder
* @see FlatFileItemWriter#setHeaderCallback(FlatFileHeaderCallback)
*/
public FlatFileItemWriterBuilder<T> headerCallback(FlatFileHeaderCallback callback) {
this.headerCallback = callback;
return this;
}
/**
* A callback for footer processing
* @param callback {@link FlatFileFooterCallback} impl
* @return The current instance of the builder
* @see FlatFileItemWriter#setFooterCallback(FlatFileFooterCallback)
*/
public FlatFileItemWriterBuilder<T> footerCallback(FlatFileFooterCallback callback) {
this.footerCallback = callback;
return this;
}
/**
* If set to true, the flushing of the buffer is delayed while a transaction is active.
*
* @param transactional defaults to true
* @return The current instance of the builder
* @see FlatFileItemWriter#setTransactional(boolean)
*/
public FlatFileItemWriterBuilder<T> transactional(boolean transactional) {
this.transactional = transactional;
return this;
}
/**
* Validates and builds a {@link FlatFileItemWriter}.
*
* @return a {@link FlatFileItemWriter}
*/
public FlatFileItemWriter<T> build() {
Assert.notNull(this.lineAggregator, "A LineAggregator is required");
Assert.notNull(this.resource, "A Resource is required");
if(this.saveState) {
Assert.hasText(this.name, "A name is required when saveState is true");
}
FlatFileItemWriter<T> writer = new FlatFileItemWriter<>();
writer.setName(this.name);
writer.setAppendAllowed(this.append);
writer.setEncoding(this.encoding);
writer.setFooterCallback(this.footerCallback);
writer.setForceSync(this.forceSync);
writer.setHeaderCallback(this.headerCallback);
writer.setLineAggregator(this.lineAggregator);
writer.setLineSeparator(this.lineSeparator);
writer.setResource(this.resource);
writer.setSaveState(this.saveState);
writer.setShouldDeleteIfEmpty(this.shouldDeleteIfEmpty);
writer.setShouldDeleteIfExists(this.shouldDeleteIfExists);
writer.setTransactional(this.transactional);
return writer;
}
}