Unit test for files

Target1.java

package com.test;

import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Target1 {
    private static final String CRLF = "\r\n";

    public void doSomething(Path path, List<Person> persons) {
        final boolean needHeader = !Files.exists(path);
        try (BufferedWriter writer = Files.newBufferedWriter(path, Charset.forName("sjis"), StandardOpenOption.CREATE,
                StandardOpenOption.APPEND);) {
            if (needHeader) {
                writer.write(getHeaders());
                writer.write(CRLF);
            }
            persons.forEach(p -> {
                String val = Arrays.stream(new String[] { p.name, String.valueOf(p.age) })
                        .collect(Collectors.joining(","));
                try {
                    writer.write(val);
                    writer.write(CRLF);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private String getHeaders() {
        return Arrays.asList("名前", "年齢").stream().collect(Collectors.joining(","));
    }
}

Target1Test.java

package com.test;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.List;

import org.junit.Test;

public class Target1Test {

    @Test
    public void testDoSomething() {
        Path path = Paths.get("/Users/tomo/tmp/test.csv");
        try {
            Files.deleteIfExists(path);
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        List<Person> persons = Arrays.asList(new Person("はなこ", 1));
        Target1 target = new Target1();
        target.doSomething(path, persons);
        persons = Arrays.asList(new Person("たろう", 2));
        target.doSomething(path, persons);
        try {
            doCheck(path);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void doCheck(Path path) throws IOException {
        List<String> lines = Files.readAllLines(path, Charset.forName("sjis"));
        String lineHead = lines.get(0);
        assertThat(lineHead, is("名前,年齢"));
        String line1 = lines.get(1);
        checkLine1(line1);
        String line2 = lines.get(2);
        checkLine2(line2);
    }

    private void checkLine1(String line1) {
        String[] cols = line1.split(",");
        assertThat(cols[0], is("はなこ"));
        assertThat(cols[1], is("1"));
    }

    private void checkLine2(String line2) {
        String[] cols = line2.split(",");
        assertThat(cols[0], is("たろう"));
        assertThat(cols[1], is("2"));
    }

}