JAVA写CSV文件

た入场券 2022-06-12 03:44 258阅读 0赞

CSV是以逗号间隔的文本文件，其文件以纯文本形式存储表格数据（数字和文本）。

在JAVA中可以通过输出文件流的方式将数据写入CSV文件。

首先定义一个对象类

public class Person {
    
    	private String name;
    	
    	private int age;
    	
    	private int sex;
    	
    	private String phone;
    	
    	private String address;
    }

然后填充下数据

List<Person> dataList = new ArrayList<Person>();
    		Person person1 = new Person();
    		person1.setName("張三");
    		person1.setSex(1);
    		person1.setAge(55);
    		person1.setPhone("13911111111");
    		person1.setAddress("北京海淀区");
    		dataList.add(person1);
    		Person person2 = new Person();
    		person2.setName("小美");
    		person2.setSex(0);
    		person2.setAge(20);
    		person2.setPhone("13911112222");
    		person2.setAddress("北京西城区");
    		dataList.add(person2);
    		Person person3 = new Person();
    		person3.setName("小明");
    		person3.setSex(1);
    		person3.setAge(25);
    		person3.setPhone("13933333333");
    		person3.setAddress("北京海淀区");
    		dataList.add(person3);

调用写文件流方法

public void writeCSV(List<Person> dataList, String finalPath) {
    		FileOutputStream out = null;
    		OutputStreamWriter osw = null;
    		BufferedWriter bw = null;
    		try {
    			File finalCSVFile = new File(finalPath);
    			out = new FileOutputStream(finalCSVFile);
    			osw = new OutputStreamWriter(out, "UTF-8");
    			// 手动加上BOM标识
    			osw.write(new String(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF }));
    			bw = new BufferedWriter(osw);
    			/**
    			 * 往CSV中写新数据
    			 */
    			String title = "";
    			title = "姓名,性别,年龄,手机号码,住址";
    			bw.append(title).append("\r");
    
    			if (dataList != null && !dataList.isEmpty()) {
    				for (Person data : dataList) {
    					bw.append(data.getName() + ",");
    					if (data.getSex() == 1) {
    						bw.append("男,");
    					} else if (data.getSex() == 0) {
    						bw.append("女,");
    					} else {
    						bw.append(" ,");
    					}
    					bw.append(data.getAge() + ",");
    					bw.append(data.getPhone() + ",");
    					bw.append(data.getAddress());
    					bw.append("\r");
    				}
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    
    			if (bw != null) {
    				try {
    					bw.close();
    					bw = null;
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			}
    			if (osw != null) {
    				try {
    					osw.close();
    					osw = null;
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			}
    			if (out != null) {
    				try {
    					out.close();
    					out = null;
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			}
    
    		}
    		System.out.println(finalPath + "数据导出成功");
    	}

注意：生成的csv文件用EXCEL打开时，总是产生乱码，但是用NOTEPAD++打开时，显示正常。这是因为导出的文件是UTF-8不含BOM格式编码的，为了要让EXCEL正确的显示，需要手动的给将要输出的内容加上BOM标识。

除了写文件流的方法外还可以通过开源类库opencsv来生成csv文件。需要引入jar包

<dependency>
    	<groupId>com.opencsv</groupId>
    	<artifactId>opencsv</artifactId>
    	<version>3.10</version>
    </dependency>

调用方法如下

public void writeCSV2(List<Person> dataList, String finalPath) {
    		try {
    			Writer writer = new FileWriter(finalPath);
    			writer.write(new String(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF }));
    			
    			StatefulBeanToCsv beanToCsv = new StatefulBeanToCsvBuilder(writer)
    					.withQuotechar(CSVWriter.NO_QUOTE_CHARACTER)
    					.withSeparator(CSVWriter.DEFAULT_SEPARATOR)
    					.withEscapechar('\\').build();
    			beanToCsv.write(dataList);
    			writer.close();
    		} catch (IOException e) {
    			e.printStackTrace();
    		} catch (CsvDataTypeMismatchException e) {
    			e.printStackTrace();
    		} catch (CsvRequiredFieldEmptyException e) {
    			e.printStackTrace();
    		}
    		System.out.println(finalPath + "数据导出成功");
    	}

生成的文件中的表头是字段名，象name，age，sex等。如果想替换成别的内容可以使用注解@CsvBindByName

public class Person {
    
    	@CsvBindByName(column = "姓名")
    	private String name;
    	
    	@CsvBindByName(column = "年龄")
    	private int age;
    	
    	@CsvBindByName(column = "性别")
    	private int sex;
    	
    	@CsvBindByName(column = "手机")
    	private String phone;
    	
    	@CsvBindByName(column = "住址")
    	private String address;
    }