本文主要介绍Java 导出CSV文件到本地及实现web下载CSV。

1.Java 导出CSV文件到本地

csvWriter:

package com.csvio;import java.io.BufferedWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.List;public class CsvWriter extends BufferedWriter {/*** set wirter* * @param out writer*/public CsvWriter(final Writer out) {super(out);}/*** csv Write line* * @param csvLine*            csv line* @throws IOException IOException*/public void writeLine(final List<String> csvLine) throws IOException {StringBuffer sb = new StringBuffer();for (int i = 0; i < csvLine.size(); i++) {String line = csvLine.get(i);if (line == null) {line = "";}sb.append("\"").append(line.replaceAll("\"", "\"\"")).append("\",");}super.write(sb.deleteCharAt(sb.length() - 1).toString());super.newLine();}}

Student.java

package com.csvio;public class Student {private String name;private String sex;private int age;public Student() {}public Student(String name, String sex, int age) {this.name = name;this.sex = sex;this.age = age;}public int getAge() {return age;}public String getName() {return name;}public String getSex() {return sex;}public void setAge(int age) {this.age = age;}public void setName(String name) {this.name = name;}public void setSex(String sex) {this.sex = sex;}@Overridepublic String toString() {return "Student [toString()=" + this.name + "-->" + this.sex + "-->"+ this.age + "]";}
}

client：

package com.csvio;import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;public class CsvClient {/*** @param args*/public static void main(String[] args) {File file = getFile();List<Student> stooges = new ArrayList<Student>();for (int i=0;i<5;i++){Student stu = new Student();stu.setAge(i+10);stu.setName("name " +i);stu.setSex(i/2==0 ?"boy":"girl");stooges.add(stu);}CsvWriter cw = null;try {
// J2EE Web下载时为下面注释的代码，传人的参数是HttpServletResponse
//            cw = new CsvWriter(response.getWriter());cw = new CsvWriter(new PrintWriter(file));for (Student stu : stooges) {cw.writeLine(getCsvLine(stu));}cw.flush();} catch (Exception e) {e.printStackTrace();} finally {try {if (cw != null) {cw.close();}} catch (IOException e) {e.printStackTrace();}}System.out.println("Done.");}private static List<String> getCsvLine(Student stu) {List<String> csvLine = new ArrayList<String>();csvLine.add(stu.getName());csvLine.add(Integer.toString(stu.getAge()));csvLine.add(stu.getSex());return csvLine;}private static File getFile() {String path = "E:\\test\\";String filename="abc.csv";File directory = new File(path);if (!directory.exists())directory.mkdirs();File file = new File(path + filename);if (!file.exists()){try {file.createNewFile();} catch (IOException e1) {e1.printStackTrace();}}return file;}}

2. web下载CSV

web下载csv的原理和输出到本地一致，就是将HttpServletResponse的流内容（writer）写入到浏览器，前提是该response的header中content-Type要告诉浏览器以下载模式接受，具体参数参见http://blog.csdn.net/bluefish625/article/details/6659288 。