CSVUtil 实现 csv文件上传下载，判断字符集编码
CSVUtil 实现 csv文件上传下载，判断字符集编码
-
- 一、maven依赖
- 二、CSVUtil.java
- 三、CSVController.java（测试）
- 四、测试结果
GitHub: link. 欢迎star
注意：本篇博客风格（不多比比就是撸代码!!!）
一、maven依赖
<dependency>
<groupId>org.apache.commonsgroupId>
<artifactId>commons-csvartifactId>
<version>1.9.0version>
dependency>
二、CSVUtil.java
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 javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.*;
import java.util.function.Function;
/**
* @author Andon
* 2021/12/21
*
* 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;
}
/**
* 下载文件
*
* @param response HttpServletResponse
* @param file File
*/
public static boolean downloadFile(HttpServletResponse response, File file, String fileName) {
FileInputStream fileInputStream = null;
BufferedInputStream bufferedInputStream = null;
OutputStream os = null;
try {
// 设置csv文件下载头信息
response.setContentType("application/octet-stream");
response.addHeader("Content-Disposition", "attachment; filename=" + new String(fileName.getBytes(StandardCharsets.UTF_8), "ISO8859-1") + ".csv");
fileInputStream = new FileInputStream(file);
bufferedInputStream = new BufferedInputStream(fileInputStream);
os = response.getOutputStream();
//MS产本头部需要插入BOM
//如果不写入这几个字节，会导致用Excel打开时，中文显示乱码
os.write(new byte[]{(byte) 0xEF, (byte) 0xBB, (byte) 0xBF});
byte[] buffer = new byte[1024];
int i = bufferedInputStream.read(buffer);
while (i != -1) {
os.write(buffer, 0, i);
i = bufferedInputStream.read(buffer);
}
return true;
} catch (IOException e) {
e.printStackTrace();
} finally {
//关闭流
if (os != null) {
try {
os.flush();
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (bufferedInputStream != null) {
try {
bufferedInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fileInputStream != null) {
try {
fileInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
boolean delete = file.delete();
}
return false;
}
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;
}
}
三、CSVController.java（测试）
import com.andon.springbootutil.util.CSVUtil;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
* @author Andon
* 2021/12/21
*/
@Slf4j
@Api(tags = "CSV")
@RequestMapping("/csv")
@RestController
public class CSVController {
@ApiOperation("上传")
@PostMapping(value = "/upload")
public List<String> upload(MultipartFile multipartFile) throws IOException {
File file = CSVUtil.uploadFile(multipartFile);
assert file != null;
long count = CSVUtil.readDataCount(file.getPath());
log.info("文件-> [{}] count={}", file.getPath(), count);
List<String> list = CSVUtil.readCSVToList(file.getPath(), null);
boolean delete = file.delete();
boolean parentFileDelete = file.getParentFile().delete();
return list;
}
@ApiOperation("下载")
@GetMapping(value = "/download")
public void download(String fileName, String head, String values, HttpServletResponse httpServletResponse) throws IOException {
String[] headArr = head.split(",");
List<String[]> valueList = new ArrayList<>(headArr.length + 1);
String[] valueArr = values.split("\\|");
for (String value : valueArr) {
valueList.add(value.split(","));
}
fileName += "_" + System.currentTimeMillis();
File file = CSVUtil.makeTempCSV(fileName, headArr, valueList);
boolean b = CSVUtil.downloadFile(httpServletResponse, file, fileName);
}
}
四、测试结果
GitHub: link. 欢迎star