java解析CSV文件三种方法(openCSV)
@
一、简介
1、pom.xml
<!-- csv文件解析依赖 -->
<dependency>
<groupId>com.opencsv</groupId>
<artifactId>opencsv</artifactId>
<version>5.4</version>
</dependency>
二、手动解析CSV文件
// 析csv文件并转成bean（方法一）
public static List<CsvFile> getCsvDataMethod1(MultipartFile file) {
ArrayList<CsvFile> csvFileList = new ArrayList<>();
InputStreamReader in = null;
String s = null;
try {
in = new InputStreamReader(file.getInputStream(), "utf-8");
BufferedReader bufferedReader = new BufferedReader(in);
String line = null;
while ((line = bufferedReader.readLine()) != null) {
String[] split = line.split(",");
CsvFile csvFile = new CsvFile();
csvFile.setName(splitResult(split[0]));
csvFile.setTitle(splitResult(split[1]));
csvFile.setNumber(splitResult(split[2]));
csvFile.setType(splitResult(split[3]));
csvFile.setPersonnel(splitResult(split[4]));
csvFile.setTime(splitResult(split[5]));
csvFileList.add(csvFile);
}
} catch (IOException e) {
e.printStackTrace();
}
return csvFileList;
}
去重引号""
private static String splitResult(String once) {
String result = "";
for (int i = 0; i < once.length(); i++) {
if (once.charAt(i) != '"') {
result += once.charAt(i);
}
}
return result;
}
三、openCSV解析CSV文件
/**
* 解析csv文件并转成bean（方法二）
*
* @param file csv文件
* @return 数组
*/
public static List<String[]> getCsvDataMethod2(MultipartFile file) {
List<String[]> list = new ArrayList<String[]>();
int i = 0;
try {
CSVReader csvReader = new CSVReaderBuilder(
new BufferedReader(
new InputStreamReader(file.getInputStream(), "utf-8"))).build();
Iterator<String[]> iterator = csvReader.iterator();
while (iterator.hasNext()) {
String[] next = iterator.next();
//去除第一行的表头，从第二行开始
if (i >= 1) {
list.add(next);
}
i++;
}
return list;
} catch (Exception e) {
System.out.println("CSV文件读取异常");
return list;
}
}
四、openCSV解析CSV文件(结果为实体类)
工具类:
/**
* 解析csv文件并转成bean（方法三）
*
* @param file csv文件
* @param clazz 类
* @param <T> 泛型
* @return 泛型bean集合
*/
public static <T> List<T> getCsvDataMethod3(MultipartFile file, Class<T> clazz) {
InputStreamReader in = null;
CsvToBean<T> csvToBean = null;
try {
in = new InputStreamReader(file.getInputStream(), "utf-8");
HeaderColumnNameMappingStrategy<T> strategy = new HeaderColumnNameMappingStrategy<>();
strategy.setType(clazz);
csvToBean = new CsvToBeanBuilder<T>(in).withMappingStrategy(strategy).build();
} catch (Exception e) {
logger.error("数据转化失败");
return null;
}
return csvToBean.parse();
}
实体类：
import com.opencsv.bean.CsvBindByName;
import lombok.Data;
@Data
public class CsvFile {
@CsvBindByName(column = "name")
private String name;
@CsvBindByName(column = "title")
private String title;
@CsvBindByName(column = "number")
private String number;
@CsvBindByName(column = "type")
private String type;
@CsvBindByName(column = "personnel")
private String personnel;
@CsvBindByName(column = "time")
private String time;
}
五、整理完成的CsvUtils
import com.lydms.testopencsv.domain.CsvFile;
import com.opencsv.CSVReader;
import com.opencsv.CSVReaderBuilder;
import com.opencsv.bean.CsvToBean;
import com.opencsv.bean.CsvToBeanBuilder;
import com.opencsv.bean.HeaderColumnNameMappingStrategy;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.web.multipart.MultipartFile;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class CsvUtils {
private static final Logger logger = LogManager.getLogger(CsvUtils.class);
/**
* 解析csv文件并转成bean（方法二）
*
* @param file csv文件
* @return 数组
*/
public static List<String[]> getCsvDataMethod2(MultipartFile file) {
List<String[]> list = new ArrayList<String[]>();
int i = 0;
try {
CSVReader csvReader = new CSVReaderBuilder(
new BufferedReader(
new InputStreamReader(file.getInputStream(), "utf-8"))).build();
Iterator<String[]> iterator = csvReader.iterator();
while (iterator.hasNext()) {
String[] next = iterator.next();
//去除第一行的表头，从第二行开始
if (i >= 1) {
list.add(next);
}
i++;
}
return list;
} catch (Exception e) {
System.out.println("CSV文件读取异常");
return list;
}
}
/**
* 解析csv文件并转成bean（方法三）
*
* @param file csv文件
* @param clazz 类
* @param <T> 泛型
* @return 泛型bean集合
*/
public static <T> List<T> getCsvDataMethod3(MultipartFile file, Class<T> clazz) {
InputStreamReader in = null;
CsvToBean<T> csvToBean = null;
try {
in = new InputStreamReader(file.getInputStream(), "utf-8");
HeaderColumnNameMappingStrategy<T> strategy = new HeaderColumnNameMappingStrategy<>();
strategy.setType(clazz);
csvToBean = new CsvToBeanBuilder<T>(in).withMappingStrategy(strategy).build();
} catch (Exception e) {
logger.error("数据转化失败");
return null;
}
return csvToBean.parse();
}
/**
* 解析csv文件并转成bean（方法一）
*
* @param file
* @return
*/
public static List<CsvFile> getCsvDataMethod1(MultipartFile file) {
ArrayList<CsvFile> csvFileList = new ArrayList<>();
InputStreamReader in = null;
String s = null;
try {
in = new InputStreamReader(file.getInputStream(), "utf-8");
BufferedReader bufferedReader = new BufferedReader(in);
String line = null;
while ((line = bufferedReader.readLine()) != null) {
String[] split = line.split(",");
CsvFile csvFile = new CsvFile();
csvFile.setName(splitResult(split[0]));
csvFile.setTitle(splitResult(split[1]));
csvFile.setNumber(splitResult(split[2]));
csvFile.setType(splitResult(split[3]));
csvFile.setPersonnel(splitResult(split[4]));
csvFile.setTime(splitResult(split[5]));
csvFileList.add(csvFile);
}
} catch (IOException e) {
e.printStackTrace();
}
return csvFileList;
}
private static String splitResult(String once) {
String result = "";
for (int i = 0; i < once.length(); i++) {
if (once.charAt(i) != '"') {
result += once.charAt(i);
}
}
return result;
}
}
六、相关地址
https://www.cnblogs.com/xhj99/p/13536465.html
https://github.com/li395092734/test-opencsv
https://files.cnblogs.com/files/blogs/604830/csvfile.zip
