package sample.context.report.csv;
import java.io.*;
import java.util.*;
import org.apache.commons.lang3.StringUtils;
import lombok.*;
import sample.InvocationException;
/**
* CSVの読込処理をサポートするユーティリティです。
*/
@Data
@AllArgsConstructor
public class CsvReader {
private byte[] data;
private InputStream ins;
private CsvLayout layout = new CsvLayout();
/** バイナリリソース経由での読み込み時にtrue */
public boolean fromBinary() {
return data != null;
}
/**
* CSV読込処理を行います。
* <p>大量データ処理を想定してメモリ内に全展開するのではなく、Iteratorを用いた
* 行処理形式を利用しています。
* @param logic
*/
public void read(final CsvReadLine logic) {
InputStream ins = null;
try {
ins = fromBinary() ? new ByteArrayInputStream(data) : this.ins;
readStream(ins, logic);
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new InvocationException("リソース処理中に例外が発生しました", e);
} finally {
if (fromBinary()) {
closeQuietly(ins);
}
}
}
private void closeQuietly(final Closeable closeable) {
try {
if (closeable != null) {
closeable.close();
}
} catch (final IOException ioe) {
}
}
public void readStream(final InputStream in, final CsvReadLine logic) throws Exception {
PushbackReader reader = new PushbackReader(new InputStreamReader(in, layout.getCharset()), 2);
try {
int lineNum = 0;
boolean title = false;
while (hasNext(in, reader)) {
lineNum++;
List<String> row = readStreamLine(reader); // ヘッダ定義でも行を読み込み、シークを先に進める
if (lineNum == 1 && StringUtils.isNotBlank(layout.getHeader())) {
title = true;
continue; // ヘッダ定義存在時は最初の行をスキップ
}
logic.execute(title ? lineNum - 1 : lineNum, row);
}
} finally {
closeQuietly(reader);
}
}
/** 行の存在判定を行います */
private boolean hasNext(final InputStream in, final PushbackReader reader) throws Exception {
in.available();
int i = reader.read();
if (i != -1) {
reader.unread(i);
return true;
}
return false;
}
/** InputStreamから行文字列を取得してparseLineを実行します */
private List<String> readStreamLine(final PushbackReader reader) throws Exception {
boolean inQt = false;
char qt = layout.getQuote();
String eol = layout.getEolSymbols();
StringBuilder sb = new StringBuilder();
int cp = -1;
while ((cp = nextCodePoint(reader)) != -1) {
sb.appendCodePoint(cp);
if (qt == cp) {
if (inQt) {
int len = 1;
while ((cp = nextCodePoint(reader)) != -1) {
if (qt == cp) {// エスケープ
len++;
sb.appendCodePoint(cp);
} else { // 終端
reader.unread(Character.toChars(cp));
break;
}
}
if (len % 2 != 0) {
inQt = (len != 1);
} else {
inQt = true;
}
} else if (!layout.isNonQuote()) {
inQt = true;
}
}
if (!inQt && sb.toString().endsWith(eol)) { // 行処理
return parseRow(stripEol(sb));
}
}
if (sb.length() > 0) {
if (sb.toString().endsWith(eol)) {
return parseRow(stripEol(sb));
} else {
return parseRow(sb.toString());
}
}
return new ArrayList<>();
}
/** サロゲートペアを考慮した次の文字位置を返します */
private int nextCodePoint(final PushbackReader r) throws IOException {
int i = r.read();
if (i == -1) {
return -1;
}
char ch = (char) i;
if (Character.isHighSurrogate(ch)) {
char lo = (char) r.read();
if (Character.isLowSurrogate(lo)) {
return Character.toCodePoint(ch, lo);
} else {
throw new IOException("想定外のサロゲートペアを検出しました。[" + String.valueOf(ch) + ", " + String.valueOf(lo) + "]");
}
}
return String.valueOf(ch).codePointAt(0);
}
private String stripEol(StringBuilder sb) {
return sb.substring(0, sb.length() - layout.getEolSymbols().length());
}
/** CSV文字列を解析して列一覧を返します */
public List<String> parseRow(String row) {
int pdelim = String.valueOf(layout.getDelim()).codePointAt(0);
int pquote = String.valueOf(layout.getQuote()).codePointAt(0);
List<String> columns = new ArrayList<>();
StringBuilder column = new StringBuilder();
boolean inQuote = false;
int max = row.codePointCount(0, row.length());
for (int i = 0; i < max; i = row.offsetByCodePoints(i, 1)) {
int c = row.codePointAt(i);
if (c == pquote) {
if (inQuote) {
int cnt = 1;
column.append(Character.toChars(c));
int next = row.offsetByCodePoints(i, 1);
for (; next < max; next = row.offsetByCodePoints(next, 1)) {
int c2 = row.codePointAt(next);
if (c2 != pquote) {
break;
} else {
column.append(Character.toChars(c2));
cnt++;
i = next;
}
}
if (cnt % 2 != 0) {
inQuote = false;
}
} else if (!layout.isNonQuote()) {
inQuote = true;
column.append(Character.toChars(c));
} else {
column.append(Character.toChars(c));
}
} else if (c == pdelim && !inQuote) { // 列切替
columns.add(unescape(StringUtils.trimToEmpty(column.toString())));
column = new StringBuilder();
inQuote = false;
} else { // 末尾追記
column.append(Character.toChars(c));
}
}
columns.add(unescape(StringUtils.trimToEmpty(column.toString())));
return columns;
}
private String unescape(String input) {
if (StringUtils.isBlank(input) || layout.isNonQuote()) {
return input;
}
char delim = layout.getDelim();
char quote = layout.getQuote();
String quoteStr = String.valueOf(quote);
String eolStr = layout.getEolSymbols();
List<String> eols = new ArrayList<>(eolStr.length());
for (int i = 0, n = eolStr.codePointCount(0, eolStr.length()); i < n; i++) {
eols.add(String.valueOf(Character.toChars(eolStr.codePointAt(i))));
}
if (input.charAt(0) != quote || input.charAt(input.length() - 1) != quote) {
return input;
}
String quoteless = input.subSequence(1, input.length() - 1).toString();
String unescape;
boolean eolsAny = false;
for (String eol : eols) {
if (StringUtils.containsAny(quoteless, eol)) {
eolsAny = true;
break;
}
}
if (StringUtils.containsAny(quoteless, delim, quote) || eolsAny) {
unescape = StringUtils.replace(quoteless, quoteStr + quoteStr, quoteStr);
} else {
unescape = input;
}
int q1 = unescape.indexOf(quote);
int q2 = unescape.lastIndexOf(quoteStr);
if (q1 != q2 && q1 == 0 && unescape.endsWith(quoteStr)) {
return unescape.substring(1, q2);
}
return unescape;
}
public static CsvReader of(byte[] data) {
return new CsvReader(data, null, new CsvLayout());
}
public static CsvReader of(byte[] data, CsvLayout layout) {
return new CsvReader(data, null, layout);
}
public static CsvReader of(InputStream ins) {
return new CsvReader(null, ins, new CsvLayout());
}
public static CsvReader of(InputStream ins, CsvLayout layout) {
return new CsvReader(null, ins, layout);
}
/** 行レベルのCSV読込処理を表現します。 */
public static interface CsvReadLine {
/**
* @param lineNum 実行行番号(1開始)
* @param cols 解析された列一覧
*/
void execute(int lineNum, final List<String> cols);
}
}
