Java Read CSV File In Java With OpenCSV library 以及中文件乱码解决, Mapping CSV with Java beans

sample.csv文件:

COUNTRY,CAPITAL,POPULATIONIndia,New Delhi, 1.21BPeople's republic of China,Beijing, 1.34BUnited States,Washington D.C., 0.31B

一.使用readNext()方法一行一行读CSV文件,返回字符串数组

package com.jiangge.csv.opencsvtest;import java.io.FileReader;import java.io.IOException;import au.com.bytecode.opencsv.CSVReader;//COUNTRY,CAPITAL,POPULATION//India,New Delhi, 1.21B//People's republic of China,Beijing, 1.34B//United States,Washington D.C., 0.31B/** * use readNext() method of CSVReader class to read CSV file line by line.  * It returns a String array for each value in row. */public class ReadLineByLine {public static void main(String[] args) throws IOException {String csvFilename = "C:\\sample.csv";CSVReader csvReader = new CSVReader(new FileReader(csvFilename));String[] row = null;while((row = csvReader.readNext()) != null) {    System.out.println(row[0] + " # " + row[1] + " #  " + row[2]);}//...csvReader.close();}}

输出结果:

COUNTRY # CAPITAL #  POPULATIONIndia # New Delhi #   1.21BPeople's republic of China # Beijing #   1.34BUnited States # Washington D.C. #   0.31B

二 使用 readAll()方法一次读取整个CSV文件,返回 List

package com.jiangge.csv.opencsvtest;import java.io.FileReader;import java.io.IOException;import java.util.List;import au.com.bytecode.opencsv.CSVReader;//COUNTRY,CAPITAL,POPULATION//India,New Delhi, 1.21B//People's republic of China,Beijing, 1.34B//United States,Washington D.C., 0.31B/** * read full CSV file once. The readAll() method of CSVReader class comes handy for this. * The readAll() method returns a List of String[] for given CSV file. * @author jiangge */public class ReadAllTest {public static void main(String[] args) throws IOException {String[] row = null;String csvFilename = "C:\\sample.csv"; CSVReader csvReader = new CSVReader(new FileReader(csvFilename));List content = csvReader.readAll(); for (Object object : content) {    row = (String[]) object;    System.out.println(row[0] + " # " + row[1]+ " #  " + row[2]);}//...csvReader.close();}}

输出结果:

COUNTRY # CAPITAL #  POPULATIONIndia # New Delhi #   1.21BPeople's republic of China # Beijing #   1.34BUnited States # Washington D.C. #   0.31B

三. 使用其他的分隔符号, 和跳过某些行--具体解释看这里:点击打开链接

CSVReader reader = new CSVReader(new FileReader(file), ';')
CSVReader reader = new CSVReader(new FileReader(file), '#')

跳过前5行,从第6行开始:

CSVReader reader = new CSVReader(new FileReader(file), ',', '\'', 5);

 
四.Mapping CSV with Java beans

1.java bean

package com.jiangge.csv.opencsvtest;public class Country {private String countryName;private String capital;private String population;public String getPopulation() {return population;}public void setPopulation(String population) {this.population = population;}public String getCountryName() {return countryName;}public void setCountryName(String countryName) {this.countryName = countryName;}public String getCapital() {return capital;}public void setCapital(String capital) {this.capital = capital;}}

2.关联JavaBean,Now we can map this bean with Opencsv and read the CSV file

package com.jiangge.csv.opencsvtest;import java.io.DataInputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.InputStreamReader;import java.util.List;import au.com.bytecode.opencsv.CSVReader;import au.com.bytecode.opencsv.bean.ColumnPositionMappingStrategy;import au.com.bytecode.opencsv.bean.CsvToBean;//COUNTRY,CAPITAL,POPULATION//India,New Delhi, 1.21B//People's republic of China,Beijing, 1.34B//United States,Washington D.C., 0.31B/** * map this bean(Country.java) with Opencsv and read the CSV file. Check out below example: * @author jiangge */public class JavaBeanMapWithCSV {public static void main(String[] args) throws FileNotFoundException {ColumnPositionMappingStrategy strategy = new ColumnPositionMappingStrategy();strategy.setType(Country.class); // 关联JavaBeanString[] columns = new String[] {"countryName", "capital"}; // the fields to bind do in your JavaBean,JavaBean里的类变量属性strategy.setColumnMapping(columns);CsvToBean csv = new CsvToBean();String csvFilename = "C:\\sample.csv";CSVReader csvReader = new CSVReader(new FileReader(csvFilename));//    DataInputStream in = new DataInputStream(new FileInputStream(new File(csvFilename)));//        csvReader = new CSVReader(new InputStreamReader(in,"utf-8"),',', '\'', 1); //这两行注释掉的内容可以解决中文乱码问题        List list = csv.parse(strategy, csvReader);for (Object object : list) {Country country = (Country) object;System.out.println(country.getCapital());}}}

输出结果:

CAPITALNew DelhiBeijingWashington D.C.

OpenCSV library中文乱码解决方法:

DataInputStream in = new DataInputStream(new FileInputStream(new File(csvFilename)));csvReader = new CSVReader(new InputStreamReader(in,"utf-8"),',', '\'', 1); //这两行注释掉的内容可以解决中文乱码问题

如果想让 属性为 int类型,该如何办呢?参考我这篇文章:http://blog.csdn.net/xiaowanggedege/article/details/17799049

参考资料:

http://viralpatel.net/blogs/java-read-write-csv-file/