CSV文件简介:
Comma Separated Values
,简称
CSV,即
逗号分隔值
,是一种纯文本格式,用来存储数据。在
CSV
中,数据的字段由逗号分开。
CSV
文件是一个计算机数据文件用于执行审判和真正的组织工具,逗号分隔的清单。常常被用于移动表格数据之间的两个不同的计算机程序,例如关系数据库程序和电子表格程序。建议用记事本新建一个文件然后修改后缀名,也建议用记事本打开CSV文件。用Excel打开,有时候会报错。
下面是最开始写的比较累赘的代码:
package
test
;
import
java
.
io
.
BufferedReader
;
import
java
.
io
.
BufferedWriter
;
import
java
.
io
.
File
;
import
java
.
io
.
FileNotFoundException
;
import
java
.
io
.
FileReader
;
import
java
.
io
.
FileWriter
;
import
java
.
io
.
IOException
;
public
class
OperateCSVfile
{
public
static
void
main
(
String
[]
args
){
String
[]
str
=
{
"省"
,
"市"
,
"区"
,
"街"
,
"路"
,
"里"
,
"幢"
,
"村"
,
"室"
,
"园"
,
"苑"
,
"巷"
,
"号"
};
File
inFile
=
new
File
(
"C://in.csv"
);
// 读取的CSV文件
File outFile = new File("C://out.csv");//写出的CSV文件
String inString = "";
String tmpString = "";
try {
BufferedReader reader = new BufferedReader(new FileReader(inFile));
BufferedWriter writer = new BufferedWriter(new FileWriter(outFile));
while((inString = reader.readLine())!= null){
char [] c = inString.toCharArray();
String [] value = new String[c.length];
String result = "";
for(int i = 0;i < c.length;i++){
value[i] = String.valueOf(c[i]);
for(int j = 0;j < str.length;j++){
if(value[i].equals(str[j])){
String tmp = value[i];
value[i] = "," + tmp + ",";
}
}
result += value[i];
}
writer.write(inString);
writer.newLine();
}
reader.close();
writer.close();
} catch (FileNotFoundException ex) {
System.out.println("没找到文件!");
} catch (IOException ex) {
System.out.println("读写文件出错!");
}
}
}
利用String类的replace()方法之后的代码简化为;
package
test
;
import
java
.
io
.
BufferedReader
;
import
java
.
io
.
BufferedWriter
;
import
java
.
io
.
File
;
import
java
.
io
.
FileNotFoundException
;
import
java
.
io
.
FileReader
;
import
java
.
io
.
FileWriter
;
import
java
.
io
.
IOException
;
public
class
OperateCSVfile
{
public
static
void
main
(
String
[]
args
){
String
[]
str
=
{
"省"
,
"市"
,
"区"
,
"街"
,
"路"
,
"里"
,
"幢"
,
"村"
,
"室"
,
"园"
,
"苑"
,
"巷"
,
"号"
};
File
inFile
=
new
File
(
"C://in.csv"
);
// 读取的CSV文件
File outFile = new File("C://out.csv");//写出的CSV文件
String inString = "";
String tmpString = "";
try {
BufferedReader reader = new BufferedReader(new FileReader(inFile));
BufferedWriter writer = new BufferedWriter(new FileWriter(outFile));
while((inString = reader.readLine())!= null){
for(int i = 0;i
tmpString = inString.replace(str[i], "," + str[i] + ",");
inString = tmpString;
}
writer
.
write
(
inString
);
writer
.
newLine
();
}
reader
.
close
();
writer
.
close
();
}
catch
(
FileNotFoundException
ex
)
{
System
.
out
.
println
(
"没找到文件!"
);
}
catch
(
IOException
ex
)
{
System
.
out
.
println
(
"读写文件出错!"
);
}
}
}
效果图;
之后我又在网上查了一下资料,发现java有专门操作CSV文件的类和方法。java开源框架csvreader提供了一个轻量级的、简单方便的统一操作接口可用。要使用CsvReader,CsvWriter需要下载一个javacsv.jar导入到项目中才行,在项目上点击右键--属性--库--添加jar文件,选择javacsv.jar文件即可,然后在程序中用import com.csvreader.CsvReader,import com.csvreader.CsvWriter导入即可。
代码如下:
package
test
;
import
com
.
csvreader
.
CsvReader
;
import
com
.
csvreader
.
CsvWriter
;
import
java
.
io
.
BufferedReader
;
import
java
.
io
.
BufferedWriter
;
import
java
.
io
.
File
;
import
java
.
io
.
FileNotFoundException
;
import
java
.
io
.
FileReader
;
import
java
.
io
.
FileWriter
;
import
java
.
io
.
IOException
;
public
class
readandwrite
{
public
static
void
main
(
String
[]
args
)
throws
IOException
{
String
[]
str
=
{
"省"
,
"市"
,
"区"
,
"街"
,
"路"
,
"里"
,
"幢"
,
"村"
,
"室"
,
"园"
,
"苑"
,
"巷"
,
"号"
};
String
inString
=
""
;
String
tmpString
=
""
;
File
inFile
=
new
File
(
"C://in.csv"
);
// 读取的CSV文件
File outFile = new File("C://outtest.csv");//输出的CSV文
try {
BufferedReader reader = new BufferedReader(new FileReader(inFile));
BufferedWriter writer = new BufferedWriter(new FileWriter(outFile));
CsvReader creader = new CsvReader(reader, ',');
CsvWriter cwriter = new CsvWriter(writer,',');
while(creader.readRecord()){
inString = creader.getRawRecord();//读取一行数据
for(int i = 0;i < str.length;i++){
tmpString = inString.replace(str[i], "," + str[i] + ",");
inString = tmpString;
}
//第一个参数表示要写入的字符串数组,每一个元素占一个单元格,第二个参数为true时表示写完数据后自动换行
cwriter.writeRecord(inString.split(","), true);
//注意,此时再用cwriter.write(inString)方法写入数据将会看到只往第一个单元格写入了数据,“,”没起到调到下一个单元格的作用
//如果用cwriter.write(String str)方法来写数据,则要用cwriter.endRecord()方法来实现换行
//cwriter.endRecord();//换行
cwriter.flush();//刷新数据
}
creader.close();
cwriter.close();
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
}
}
得到同样的效果。