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CSVUtil.java

package com . andon . springbootutil . util ;

import lombok . extern . slf4j . Slf4j ;

import org . apache . commons . csv . CSVFormat ;

import org . apache . commons . csv . CSVParser ;

import org . apache . commons . csv . CSVPrinter ;

import org . apache . commons . csv . CSVRecord ;

import org . springframework . util . ObjectUtils ;

import org . springframework . web . multipart . MultipartFile ;

import java . io .*;

import java . net . URL ;

import java . nio . charset . StandardCharsets ;

import java . nio . file . Files ;

import java . nio . file . Path ;

import java . nio . file . Paths ;

import java . util .*;

import java . util . function . Consumer ;

import java . util . function . Function ;

/**

* @author Andon

* 2021/12/21

* <p>

* csv文件上传下载

@ Slf4j

public class CSVUtil {

//行尾分隔符定义

private static final String NEW_LINE_SEPARATOR = java . security . AccessController . doPrivileged ( new sun . security . action . GetPropertyAction ( "line.separator" ));

//上传文件的存储位置

private final static URL PATH = Thread . currentThread (). getContextClassLoader (). getResource ( "" );

private static final CSVFormat CSV_FORMAT = CSVFormat . DEFAULT . builder (). setIgnoreEmptyLines ( false ). setRecordSeparator ( NEW_LINE_SEPARATOR ). setQuote ( null ). build ();

/**

* 上传文件

* @param multipartFile MultipartFile

public static File uploadFile ( MultipartFile multipartFile ) {

assert PATH != null ;

// 获取上传路径

String path = PATH . getPath () + UUID . randomUUID (). toString (). replaceAll ( "-" , "" ) + File . separator + multipartFile . getOriginalFilename ();

try {

// 通过将给定的路径名字符串转换为抽象路径名来创建新的 File实例

File file = new File ( path );

// 此抽象路径名表示的文件或目录是否存在

if (! file . getParentFile (). exists ()) {

// 创建由此抽象路径名命名的目录，包括任何必需但不存在的父目录

boolean mkdirs = file . getParentFile (). mkdirs ();

}

// 转换为一般file文件

multipartFile . transferTo ( file );

log . info ( "上传文件成功，文件名===>{}, 路径===>{}" , multipartFile . getOriginalFilename (), file . getPath ());

return file ;

} catch ( IOException e ) {

log . error ( "上传文件失败 error:{} e:{}" + e . getMessage (), e );

return null ;

}

/**

* 读取CSV文件的内容

* @param filePath 文件路径

* @param indexArr 参与计算的列的组合角标

* @return 表内容集合，key是组合ID，value是整行数据

public static Map < String , String > readCSVToMap ( String filePath , String [] indexArr ) throws IOException {

String charset = charset ( filePath );

try ( FileInputStream fileInputStream = new FileInputStream ( filePath )) {

return records ( fileInputStream , charset , csvRecords -> {

Map < String , String > map = new HashMap <>();

//通过首行获取列数量

int colNum = csvRecords . get ( 0 ). size ();

for ( CSVRecord record : csvRecords ) {

// 每行的内容

List < String > value = new ArrayList <>( colNum );

for ( int i = 0 ; i < colNum ; i ++) {

value . add ( record . get ( i ));

}

// 每行ID

List < String > key = new ArrayList <>( indexArr . length );

for ( String index : indexArr ) {

key . add ( record . get ( Integer . parseInt ( index )));

}

String id = String . join ( "," , key );

if (! map . containsKey ( id )) {

map . put ( id , String . join ( "," , value ));

}

return map ;

});

}

/**

* 读取CSV文件的内容

* @param filePath 文件路径

* @param indexArr 参与计算的列的组合角标

* @return 表内容集合，value是参与计算的列的数据

public static List < String > readCSVToList ( String filePath , String [] indexArr ) throws IOException {

String charset = charset ( filePath );

try ( FileInputStream fileInputStream = new FileInputStream ( filePath )) {

return records ( fileInputStream , charset , csvRecords -> {

List < String > values = new ArrayList <>();

for ( CSVRecord record : csvRecords ) {

// 每行的内容

List < String > value = new ArrayList <>();

if ( ObjectUtils . isEmpty ( indexArr )) {

for ( String item : record ) {

value . add ( item . trim ());

}

} else {

value = new ArrayList <>( indexArr . length );

for ( String index : indexArr ) {

value . add ( record . get ( Integer . parseInt ( index )));

}

values . add ( String . join ( "," , value ));

}

return values ;

});

}

/**

* 读取CSV数据条目数

* @param filePath 文件路径

* @return 数据条目数

public static long readDataCount ( String filePath ) {

String charset = charset ( filePath );

try ( FileInputStream fileInputStream = new FileInputStream ( filePath )) {

return records ( fileInputStream , charset , csvRecords -> Long . valueOf ( csvRecords . size ()));

} catch ( IOException e ) {

log . error ( "解析CSV内容失败 error:{} e:{}" , e . getMessage (), e );

}

return 0 ;

}

/**

* 创建文件

public static File createFile ( String ... filePath ) throws IOException {

assert PATH != null ;

Path path = Paths . get ( PATH . getPath (). substring ( 1 ), filePath );

if (! path . getParent (). toFile (). exists ()) {

Files . createDirectory ( path . getParent ());

}

Files . deleteIfExists ( path );

Files . createFile ( path );

return path . toFile ();

}

public static void recordIterator ( String filePath , Consumer < Iterator < CSVRecord >> recordIteratorHandler ) throws IOException {

try ( FileInputStream fileInputStream = new FileInputStream ( filePath )) {

recordIterator ( fileInputStream , charset ( filePath ), recordIteratorHandler );

}

public static void recordIterator ( InputStream inputStream , String charset , Consumer < Iterator < CSVRecord >> recordIteratorHandler ) throws IOException {

try ( InputStreamReader inputStreamReader = new InputStreamReader ( inputStream , charset );

BufferedReader bufferedReader = new BufferedReader ( inputStreamReader );) {

CSVParser parser = CSV_FORMAT . parse ( bufferedReader );

recordIteratorHandler . accept ( parser . iterator ());

}

/**

* 增量写文件

public static void appendContentToFile ( File file , List < String []> values ) throws IOException {

synchronized ( CSVUtil . class ) {

try ( BufferedWriter bufferedWriter = new BufferedWriter ( new OutputStreamWriter ( new FileOutputStream ( file , true ), StandardCharsets . UTF_8 ))) {

CSVPrinter printer = new CSVPrinter ( bufferedWriter , CSV_FORMAT );

for ( String [] value : values ) {

printer . printRecord ( Arrays . asList ( value ));

}

printer . close ();

}

/**

* 创建CSV文件

* @param fileName File

* @param head 表头

* @param values 表体

public static File makeTempCSV ( String fileName , String [] head , List < String []> values ) throws IOException {

// 创建文件

assert PATH != null ;

File file = File . createTempFile ( fileName , ".csv" , new File ( PATH . getPath ()));

try ( BufferedWriter bufferedWriter = new BufferedWriter ( new OutputStreamWriter ( new FileOutputStream ( file ), StandardCharsets . UTF_8 ))) {

CSVPrinter printer = new CSVPrinter ( bufferedWriter , CSV_FORMAT );

// 写入表头

printer . printRecord ( Arrays . asList ( head ));

// 写入内容

for ( String [] value : values ) {

printer . printRecord ( Arrays . asList ( value ));

}

printer . close ();

}

return file ;

}

private static < R > R records ( InputStream inputStream , String charset , Function < List < CSVRecord >, R > recordsHandler ) throws IOException {

try ( InputStreamReader inputStreamReader = new InputStreamReader ( inputStream , charset );

BufferedReader bufferedReader = new BufferedReader ( inputStreamReader );) {

CSVParser parser = CSV_FORMAT . parse ( bufferedReader );

// 读取文件每行内容

List < CSVRecord > records = parser . getRecords ();

return recordsHandler . apply ( records );

}

/**

* 判断文件字符编码

public static String charset ( String path ) {

String charset = "GBK" ;

byte [] first3Bytes = new byte [ 3 ];

try {

boolean checked = false ;

BufferedInputStream bis = new BufferedInputStream ( new FileInputStream ( path ));

bis . mark ( 0 );

int read = bis . read ( first3Bytes , 0 , 3 );

if ( read == - 1 ) {

bis . close ();

return charset ; // 文件编码为 ANSI

} else if ( first3Bytes [ 0 ] == ( byte ) 0xFF && first3Bytes [ 1 ] == ( byte ) 0xFE ) {

charset = "UTF-16LE" ; // 文件编码为 Unicode

checked = true ;

} else if ( first3Bytes [ 0 ] == ( byte ) 0xFE && first3Bytes [ 1 ] == ( byte ) 0xFF ) {

charset = "UTF-16BE" ; // 文件编码为 Unicode big endian

checked = true ;

} else if ( first3Bytes [ 0 ] == ( byte ) 0xEF && first3Bytes [ 1 ] == ( byte ) 0xBB

&& first3Bytes [ 2 ] == ( byte ) 0xBF ) {

charset = "UTF-8" ; // 文件编码为 UTF-8

checked = true ;

}

bis . reset ();

if (! checked ) {

while (( read = bis . read ()) != - 1 ) {

if ( read >= 0xF0 )

break ;

if ( 0x80 <= read && read <= 0xBF ) // 单独出现BF以下的，也算是GBK

break ;

if ( 0xC0 <= read && read <= 0xDF ) {

read = bis . read ();

if ( 0x80 > read || read > 0xBF ) {

break ; // 双字节 (0xC0 - 0xDF),(0x80 - 0xBF),也可能在GB编码内

}

} else if ( 0xE0 <= read ) { // 也有可能出错，但是几率较小

read = bis . read ();

if ( 0x80 <= read && read <= 0xBF ) {

read = bis . read ();

if ( 0x80 <= read && read <= 0xBF ) {

charset = "UTF-8" ;

}

break ;

}

bis . close ();

} catch ( Exception e ) {

e . printStackTrace ();

}

log . info ( "--文件-> [{}] 采用的字符集为: [{}]" , path , charset );

return charset ;

}

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CSVUtil.java

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