【 tulaoshi.com - Java 】
文件操作是网站编程的重要内容之一,asp关于文件操作讨论的已经很多了,让我们来看看jsp中是如何实现的。
这里用到了两个文件,一个jsp文件一个javabean文件,通过jsp中调用javabean可以轻松读取文本文件,注意请放置一个文本文件afile.txt到web根目录的test目录下,javabean文件编译后将class文件放到对应的class目录下(tomcat环境)。
Read.jsp
<html
<head
<title读取一个文件</title
</head
<body bgcolor="#000000"
<%--调用javabean --%
<jsp:useBean id="reader" class="DelimitedDataFile" scope="request"
<jsp:setProperty name="reader" property="path" value="/test/afile.txt" /
</jsp:useBean
<h3文件内容:</h3
<p
<% int count = 0; %
<% while (reader.nextRecord() != -1) { %
<% count++; %
<b第<% out.print(count); %行:</b
<% out.print(reader.returnRecord()); %<br
<% } %
</p
</body
</html
//DelimitedDataFile.java bean文件源代码
//导入java包
import java.io.*;
import java.util.StringTokenizer;
public class DelimitedDataFile
{
private String currentRecord = null;
private BufferedReader file;
private String path;
private StringTokenizer token;
//创建文件对象
public DelimitedDataFile()
{
file = new BufferedReader(new InputStreamReader(System.in),1);
}
public DelimitedDataFile(String filePath) throws FileNotFoundException
{
path = filePath;
file = new BufferedReader(new FileReader(path));
}
//设置文件路径
public void setPath(String filePath)
{
path = filePath;
try {
file = new BufferedReader(new
FileReader(path));
} catch (FileNotFoundException e) {
System.out.println("file not found");
}
}
//得到文件路径
public String getPath() {
return path;
}
//关闭文件
public void fileClose() throws IOException
{
file.close();
}
//读取下一行记录,若没有则返回-1
public int nextRecord()
{
int returnInt = -1;
try
{
currentRecord = file.readLine();
}
catch (IOException e)
{
System.out.println("readLine problem, terminating.");
}
if (currentRecord == null)
returnInt = -1;
else
{
token = new StringTokenizer(currentRecord);
returnInt = token.countTokens();
}
return returnInt;
}
//以字符串的形式返回整个记录
public String returnRecord()
{
return currentRecord;
}
}