java web导出csv_Java 导出CSV文件及实现web下载CSV
这个下载文件是"用Java EE 5实现的网上书店实例"的更新版本, 原来版本是在NetBeans 5.5.1上开发, 新版本是用NetBeans 6.0开发,并且增加了jMaki实现的Web层. 下载地址: http://developers.sun.com.cn/blog/ada/resource/javaee_bookshop_nb6_zh_CN.zip Track
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 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
Java web下载文件功能的确很简单。如下代码片段 String fileName ="...."; response.setHeader("Content-disposition","attachment; filename="+fileName); //response.setContentType("application/ms-word"); BufferedInputStream bis = null;
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;
}
@Override
public 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 stooges = new ArrayList();
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 getCsvLine(Student stu) {
List csvLine = new ArrayList();
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 。