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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.commons.csv;

import static org.apache.commons.csv.Constants.CR;
import static org.apache.commons.csv.Constants.LF;
import static org.apache.commons.csv.Constants.SP;

import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * Prints values in a CSV format.
 */
public final class CSVPrinter implements Flushable, Closeable {

    /** The place that the values get written. */
    private final Appendable out;
    private final CSVFormat format;

    /** True if we just began a new record. */
    private boolean newRecord = true;

    /**
     * Creates a printer that will print values to the given stream following the CSVFormat.
     * 

* Currently, only a pure encapsulation format or a pure escaping format is supported. Hybrid formats (encapsulation * and escaping with a different character) are not supported. *

* * @param out * stream to which to print. Must not be null. * @param format * the CSV format. Must not be null. * @throws IOException * thrown if the optional header cannot be printed. * @throws IllegalArgumentException * thrown if the parameters of the format are inconsistent or if either out or format are null. */ public CSVPrinter(final Appendable out, final CSVFormat format) throws IOException { Assertions.notNull(out, "out"); Assertions.notNull(format, "format"); this.out = out; this.format = format; // TODO: Is it a good idea to do this here instead of on the first call to a print method? // It seems a pain to have to track whether the header has already been printed or not. if (format.getHeaderComments() != null) { for (final String line : format.getHeaderComments()) { if (line != null) { this.printComment(line); } } } if (format.getHeader() != null && !format.getSkipHeaderRecord()) { this.printRecord((Object[]) format.getHeader()); } } // ====================================================== // printing implementation // ====================================================== @Override public void close() throws IOException { if (out instanceof Closeable) { ((Closeable) out).close(); } } /** * Flushes the underlying stream. * * @throws IOException * If an I/O error occurs */ @Override public void flush() throws IOException { if (out instanceof Flushable) { ((Flushable) out).flush(); } } /** * Gets the target Appendable. * * @return the target Appendable. */ public Appendable getOut() { return this.out; } /** * Prints the string as the next value on the line. The value will be escaped or encapsulated as needed. * * @param value * value to be output. * @throws IOException * If an I/O error occurs */ public void print(final Object value) throws IOException { format.print(value, out, newRecord); newRecord = false; } /** * Prints a comment on a new line among the delimiter separated values. * *

* Comments will always begin on a new line and occupy a least one full line. The character specified to start * comments and a space will be inserted at the beginning of each new line in the comment. *

* * If comments are disabled in the current CSV format this method does nothing. * * @param comment * the comment to output * @throws IOException * If an I/O error occurs */ public void printComment(final String comment) throws IOException { if (!format.isCommentMarkerSet()) { return; } if (!newRecord) { println(); } out.append(format.getCommentMarker().charValue()); out.append(SP); for (int i = 0; i < comment.length(); i++) { final char c = comment.charAt(i); switch (c) { case CR: if (i + 1 < comment.length() && comment.charAt(i + 1) == LF) { i++; } //$FALL-THROUGH$ break intentionally excluded. case LF: println(); out.append(format.getCommentMarker().charValue()); out.append(SP); break; default: out.append(c); break; } } println(); } /** * Outputs the record separator. * * @throws IOException * If an I/O error occurs */ public void println() throws IOException { format.println(out); newRecord = true; } /** * Prints the given values a single record of delimiter separated values followed by the record separator. * *

* The values will be quoted if needed. Quotes and newLine characters will be escaped. This method adds the record * separator to the output after printing the record, so there is no need to call {@link #println()}. *

* * @param values * values to output. * @throws IOException * If an I/O error occurs */ public void printRecord(final Iterable values) throws IOException { for (final Object value : values) { print(value); } println(); } /** * Prints the given values a single record of delimiter separated values followed by the record separator. * *

* The values will be quoted if needed. Quotes and newLine characters will be escaped. This method adds the record * separator to the output after printing the record, so there is no need to call {@link #println()}. *

* * @param values * values to output. * @throws IOException * If an I/O error occurs */ public void printRecord(final Object... values) throws IOException { format.printRecord(out, values); newRecord = true; } /** * Prints all the objects in the given collection handling nested collections/arrays as records. * *

* If the given collection only contains simple objects, this method will print a single record like * {@link #printRecord(Iterable)}. If the given collections contains nested collections/arrays those nested elements * will each be printed as records using {@link #printRecord(Object...)}. *

* *

* Given the following data structure: *

* *
     * 
     * List<String[]> data = ...
     * data.add(new String[]{ "A", "B", "C" });
     * data.add(new String[]{ "1", "2", "3" });
     * data.add(new String[]{ "A1", "B2", "C3" });
     * 
     * 
* *

* Calling this method will print: *

* *
     * 
     * A, B, C
     * 1, 2, 3
     * A1, B2, C3
     * 
     * 
* * @param values * the values to print. * @throws IOException * If an I/O error occurs */ public void printRecords(final Iterable values) throws IOException { for (final Object value : values) { if (value instanceof Object[]) { this.printRecord((Object[]) value); } else if (value instanceof Iterable) { this.printRecord((Iterable) value); } else { this.printRecord(value); } } } /** * Prints all the objects in the given array handling nested collections/arrays as records. * *

* If the given array only contains simple objects, this method will print a single record like * {@link #printRecord(Object...)}. If the given collections contains nested collections/arrays those nested * elements will each be printed as records using {@link #printRecord(Object...)}. *

* *

* Given the following data structure: *

* *
     * 
     * String[][] data = new String[3][]
     * data[0] = String[]{ "A", "B", "C" };
     * data[1] = new String[]{ "1", "2", "3" };
     * data[2] = new String[]{ "A1", "B2", "C3" };
     * 
     * 
* *

* Calling this method will print: *

* *
     * 
     * A, B, C
     * 1, 2, 3
     * A1, B2, C3
     * 
     * 
* * @param values * the values to print. * @throws IOException * If an I/O error occurs */ public void printRecords(final Object... values) throws IOException { for (final Object value : values) { if (value instanceof Object[]) { this.printRecord((Object[]) value); } else if (value instanceof Iterable) { this.printRecord((Iterable) value); } else { this.printRecord(value); } } } /** * Prints all the objects in the given JDBC result set. * * @param resultSet * result set the values to print. * @throws IOException * If an I/O error occurs * @throws SQLException * if a database access error occurs */ public void printRecords(final ResultSet resultSet) throws SQLException, IOException { final int columnCount = resultSet.getMetaData().getColumnCount(); while (resultSet.next()) { for (int i = 1; i <= columnCount; i++) { print(resultSet.getObject(i)); } println(); } } }




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